Building notes on thermal upgrading of building elements

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Building notes on thermal upgrading of building elements

TECHNICAL TRANSLATION TRADUCTION TECHNIQUE 2069 Author/Auteur: Title/Titre: Reference/Reference: Translator/Traducteur:

Swiss Federal Office for Economic Development.

Building Notes on Thermal Upgrading of Building Elements.

Merkbiatter Baukorper, 211.1 - 249.3, 1980.

P. Hessel.

•

Canada Institute for Scientific and Technical Information

Institut canadien de i'informatlon scientifique et technique

Ottawa, Canada KiA OS2

•

"

PREFACE

Concern has grown in many countries over the large amounts of energy used to heat buildings. In Canada roughly one third of all secondary energy has been used to heat buildings. The cold climate and some other factors such as long transportation routes have made Canadians one of the highest per capita energy users of the world.

Many efforts are being made to improve the thermal performance of buildings.

Research and Development on the subject have increased at the Division of

Building Research of the National Research Council and elsewhere. The

capabili ties in Canada to deal with the problem have been expanded, for

example by a series of DBR seminar-workshops which have been used to transfer the latest conservation techniques to members of the construction industry across the country.

DBR staff has made efforts to stay abreast of similar efforts in other

countries. One of these countries is Switzerland where there is a coordinated effort to deal with the subject. The Federal Office for Economic Development

(Bundesamt fur Konjunkturfragen) has organized courses for professional

development as part of its Incentive Program for Thermal Upgrading of

Buildings. For these courses a series of Information Sheets (Her-kb Iatter ) were published which are the subject of this translation. These Information Sheets deal in detail with methods of improving the thermal performance of

walls, roofs, floors, ceilings, windows and doors. While they deal partly

with types of construction that are not common in Canada, many aspects and

their approach warrant attention. They provide another view of the same

problem and thus could encourage Canadians to consider new ways of dealing with the problem.

DBR has maintained good contact with the building research community in Swi tzerland over the years, for example by hosting guest workers from EMPA

(Swiss Materials and Testing Laboratory in Dubendorf near Zurich). DBR is

pleased, therefore, to make this information available to the Canadian

construction industry and wishes to express its sincere thanks to P. Hessel

who translated this paper under contract to the National Research Council

Canada, Canada Institute for Scientific and Technical Information. It was

checked and revised for technical accuracy by William Schriever, P. Eng , , a

retired member of staff of DBR/NRC, who because of his Swiss origins and

continued contact with EMPA staff and others, has a good knowledge of Canadian and Swiss terminology.

..

..

•

INFORMATION SHEETS

Information Sheets on Construction Elements

Note re numbering of Information Sheets: The first two digits indicate the chapter in the Guidelines on Thermal Upgrading of Buildings, as well as in the Handbook "Planning and Design".

Example: Information Sheet 241.1 ---'Guidelines, Chapter 2.4 ---tHandbook, Chapter 2.4

Table of Contents

Information Sheets - Walls

Walls: Exterior Insulation

Walls: Interior Insulation

Insulation plus stucco 211.1

Insulation with open-rain-screen

type cladding 211.2

Insulating stucco 211.3

Insulation using composite board 212.1

Insulation behind masonry 212.2

Insulation behind cladding 212.3

Information Sheets - Roofs Roofs: Sloped Roofs

Roofs: Flat Roofs

Interior insulation Exterior insulation Insulation by means upside-down roof

for sloped roofs 221.1 for sloped roofs 221.2 of an added

222.1

..

Information Sheets - Floors and Ceilings Floors and Ceilings: Attic Floors

Attic insulation, non-walk-on type Attic insulation, walk-on type Interior insulation for concrete slab ceilings

Interior insulation for wood joist ceilings

231.1 231.2

231.3

Doors

Windows and Doors: General Windows and Doors: Checklists

Floors and Ceilings: Slab or floor above an air space, or above an

unheated room Exterior insulation of floors

Interior insulation of floors Floors: Slab on the ground Interior insulation of floors

Information Sheets - Windows and Doors

Windows Calculation and design

Glass elements Glazing technique

Window frames made 0f wood

Window frames made of plastic Window hardware

Weatherstripping

Connecting windows to structural elements

Upgrading the glazing Replacing windows Upgrading doors Care and maintenance

Survey of condition - shutters and blinds

Survey of condition - doors

232.1 232.2 233.1 241.1 241.2 241.3 241.4 241.5 241.8 241.9 241.10 241.11 241.12 242.1 248.1 249.2 249.3

..

INFORMATION SHEET

Walls: Exterior Insulation Insulation Plus Stucco System

211.1

11

In most exterior insulation systems, insulation glued to the wall is covered

with thin, mesh-reinforced stucco, occasionally also with thick,

mesh-reinforced stucco.

glue layer

thermal insulation

undercoat of stucco and mesh reinforcement finishing coat of stucco

Stucco layer

The thin stuccos (appr-ox , 3 to 4 nun) are made with an organic binder. The thick stuccos (5 nun or thicker) are made with mineral or cement binder and thus are more brittle than the thin stuccos, Le. they are more inclined to

crack from shrinkage. Special precautions, such as grooved sheets, are

necessary for proper bonding of cement-based stucco to insulation sheets. Cement-based stuccos are mechanically more resistant than the thin-organic

stuccos. However, the mechanical resistance of thin stucco can be

..

considerably improved by using an appropriate mesh-reinforcement.

Normally stucco is applied in two coats with a plastic-covered fibreglass mesh

reinforcement between. A coloured finishing coat of stucco is applied for

Insulation Material

The most widely used insulation material for stuccoed exterior insulation systems at present is expanded, fire-resistant foamed polystyrene (PS) or mineral wool.

If there should be any warping of the insulation it should be remembered that foamed PS produces far greater stresses in the overlying stucco than does mineral wool. For that reason, only well seasoned foamed PS-sheets should be used. Cracks over the joints, frequently found with PS-sheets, are a rare occurrence with mineral-wool sheets.

Mineral wool sheets constitute a so-called "soft" base. On such a base thin stucco, tends to crack more easily from shrinkage than if applied to a harder base such as foamed PS-sheets.

Water from leaking pipes, etc. usually remains confinea to a local area. ...1ｴｾＱ

foamed PS-sheets, wheareas it tends to spread over and soak larger areas when mineral wool sheets are used.

Fire safety regulations limit the applicability of foamed PS-sheets, while mineral wool sheets can be used even in highrise buildings.

Foamed PS-sheets are usually either butt-jointed or moulded with tongue and grove joints. However, the latter offer no particular advantages.

The tickness of the insulation layer should be selected in such a way that the dew-point falls wi thin the insulation. For reasons of economy, too, its is recommended that the insulation layer be as thick as possible - up to approx. 12 cm,

Application

. Exterior insulation systems using foamed polystyrene sheets have been used in Switzerland for over 15 years for building upgrading and new construction. Through the solution of early problems considerable experience is now available.

Exterior insulation systems using mineral wool sheets have been used in SWitzerland for three or four years only and long-term practical experience is still scarce. It is still uncertain for example whether condensation water that might occur in the mineral wool sheets might not in time lead to the separation of the individual layers •

experience with foamed glass.

•

Preparation of the surface

insulation made The use of these

of polyurethane, materials is thus

The base must be solid. Surface layers that are not solidly attached to the masonry and crumbly patches must be removed. The base must be dry and free of substances which reduce adhesion. I t must have uniformly low absorbency and provide proper anchoring for the insulation system. For sensitive bases glueing and tensile adhesion tests are recommended. Inadequate bases require appropriate pre-treatment or mechanical fastening of the sheets.

Unevenness in the base up to a depth of 5 mm can usually be accommodated by the adhesive. Deeper uneven areas may have to be patched with plaster filler. I t is also possible to equalize recesses, evg , near parapets, by using thicker sheets.

Installation principles

The instructions of the contractor or systems designer must be strictly observed. Generally the sheets are laid with tight butt joints in alternating arrangement. Around corners the material must be finger jointed and the projecting "fingers" must be sanded smooth. Depending on the base, the insulation sheets are either glued to the base or mechanically fastened with nails and large washers. The sheets are either glued over the entire surface

intermediate strips. The required waiting times must be strictly observed, particularly when stucco is applied. The coats of stucco must be applied in such a way that the fibreglass reinforcement is embedded and the colour of the mesh is no longer visible.

Interfaces

Interfaces between the insulation and adjacent parts of the construction must be worked out in cooperation between architect, contractor and insulation systems designer.

At the interface between the insulation and a flat roof i t is ususally necessary to change the flashing. Window sills are usually adapted by means of metal sills or appropriate extensions of artificial stone. Window reveals should be insulated as much as possible although problems may arise when connections for shutters and window frames have to be changed. If the glazing is upgraded as well, it is sometimes possible to adapt the new frames to the new insulation system.

Expansion joints in the wall must be carried through the exterior insulation. It is also recommended to arrange for a joint along the line of support of a slab supporting a flat roof.

It is usually possible to continue the insulation underground. extruded polystyrene sheets or special coatings should be dampness.

In this case, used against

Metal parts such as tracks for blinds, house numbers, water pipes, oil filler pipes, etc. can be fastened through the insulation, but they must be especially sealed; they usually remain critical points.

Important Pointers

Different exterior insulation systems should not be combined for an "ideal" solution.

9

-Protection against wetting (rain) such as canopies are of great advantage for the exterior insulation as well.

Fancy relief-like ｦ｡ｾ｡､･ features cannot be followed by the insulation.

Horizontal or slightly sloped stucco portions exposed to the weather should be avoided.

Colours should be as light as possible, since the temperature of the stucco depends solar radiation. Avoid dark colours!

Cracks in the masonry caused by temperature changes and deflections in concrete floor slab can as a rule be bridged by the exterior insulation system. Fairly thick insulation layers are an advantage in this respect. Settlement cracks should, however, be investigated to see whether movements are still occurring.

Tenders

The following information should be included when tenders are called: existing wall construction, particularly existing base,

connections: window sills and reveals, blinds, eaves, foundation walls, expansion joints, etc.,

penetration by metal parts,

desired stucco finish (for mineral stucco only),

See also CRB standards catalogue, NPK No. 119. Position 200: Insulation with stucco.

Products

Information about the suitability of products can be obtained from:

product list "Thermal Insulation Materials", Application Area ALl,

results of comparative testing carried out in the course of the Incentive Program sponsored by EMFA (Swiss Institute for Materials Testing),

INFORMATION SHEET

Walls: Exterior Insulation

Insulation with Open-Rain-Screen Type Cladding System

211.2

An open-rain-screen system consists of an insulation layer, a vented space and a cladding. The insulation layer may be glued and/or mechanically fastened to the base.

The vented cladding ensures the elimination of water vapour that may come from the inside as well as of any rain water that may penetrate from the outside. In summer, such venting can also prevent excessive heat build-up. The optimal air space is about 3-5 cm wide. Wider spaces have no significant benefits and a width of less than 2 cm should be avoided. The diameter of air intakes and outlets should not be smaller than that of the air space.

Such systems usually do not require a vapour barrier. However, an air barrier is essential.

Insulation materials

Insulation materials for vented claddings should be of low combustibility (combustibili ty class 5) and for highrise buildings they should be non-combustible (combustibility class 6). As a rule, non-coated mineral fibres are used. Coated mineral fibre batts are unsuitable. A insulation thickness of 10 cm or more is desirable to achieve a k factor of 0.3.

Cladding

Either large sheets, butt-jointed and with sealed joints (closed cladding) or small, overlapping (shingle-like) elements may be used. The type of fastening for the cladding should be chosen carefully, particularly from the point of proper anchoring.

1 6

Z

Z

furring for cladding 5 cladding 6 joint-support 7 consoles 8 edge-support Insta11ation Installation principles A. Shingle-like cladding

The insulation is pressed between horizontally mounted furring. Vertical furring is fastened over the horizontal furring to produce an air space and as support for the cladding (such as shingles or wood siding). For very thick insulation, it is preferable to apply the furring and the insulation in two layers. This reduces the size of the wood furring and improves anchoring to the wall. Recently also metal furring for small-format shingle-type cladding has become available.

B. Butt-jointed cladding on wood furring

The supports are constructed basically in the same manner as for the shingle-like cladding. The anchorage, the size of the wood members and the arrangement of the wooden grid must suit the weight and size of the cladding sheets. The butt joints are usually sealed by special gaskets.

12

-c.

Instead of wooden furring, special metal slats can be used which are anchored in the bearing wall. If the wall is not solid enough, it may be possible to

improve the anchorage by using special dowels. The insulation is fitted

carefully between and around the slats. Horizontal or vertical members are

mounted at the appropriate spacings for fastening the sheets. Systems with adjustable members have the advantage of providing more latitude in choosing insulation thickness, ventilation space and in accommodating uneven areas.

For relatively thick insulation, they may also be more economical than wooden

furring. Early consideration should be given to the most aesthetic

arrangement of the sheets keeping in mind available standard sizes. Large

sheets require appropriate fastenings to take care of additional weight, wind forces and temperature movements.

Details

Air spaces should be vented as directly as possible.

Openings at the foundation wall should allow free air entry and free water escape, and yet prevent the entry of driving rain and water backsplash. The openings must not become plugged by plants or dirt. Animals (birds, mice, insects) must be kept out by means of suitable screens.

Details at the eaves should also allow free air escape, prevent water from entering and keep animals and insects out.

Details at adjacent construction elements such as window sills and roof

lintels must be appropriate. Windows and blinds must not be interfered with. When rigid insulation board is used, such as foamed polystyrene type F, the

vertical furring is often fastened to the masonry with dowels which pass

through the insulation. In such cases - particularly when the insulation

layer is relatively thick and when cladding panels are heavy - special

attention must be paid to the strength of the fastenings: Dowels must have adequate bending, tensile and shear strength.

Important Pointers

Wooden furring should be pretreated with preservatives, not so much against dampness as against insect damage.

All metal parts must be made of non-rusting metals.

The construction must be watertight to withstand driving rain. It must also prevent water from penetrating through joints during high winds. Damage from small leaks can be prevented by good ventilation.

The insulation boards should lie as flat as possible on the bearing wall to prevent empty spaces in which air could circulate.

Tenders

The following information should be included when tenders are called: existing wall construction,

required work, possible alternatives,

required k-factor in W/m2k, or insulation thickness, cladding type, total area, connections.

Products

Information about the suitability of products can be obtained from:

product list "Thermal Insulation Materials", Application Area A 1.2,

results of comparative testing carried out in the course of Incentive Program sponsored by EMPA (Swiss Institute for Materials Testing),

Swiss Wood Council (LIGNUM), Zurich, Swiss Metal Union (SHU), Zurich.

INFORMATION SHEET

Walls: Exterior Insulation Insulating Stucco

System Composition

211.3

Insaluting stuccos consist of a ready-mixed dry mortar mix in bags to which an insulating material is added for application in a single operation. Most of the insulating stuccos on the market consist of over 80% pressure-foamed polystyrene beads with a diameter of about 0.5 rom to 4 rom, hydraulic bonding agents of lime and cement, and chemical additives. Some insulating stuccos are made wholly or in part with crushed polystyrene wastes from the bui Ld Ing material or packaging industry. This kind of mixture may result in certain disadvantages in terms of workability, compressive strength and moisture properties.

Structure

Most insulating stuccos consist of three layers which are applied in three separate operations:

1. Application of a cement mortar or special rendering mortar, about 0.5 cm in thickness, by hand or with a sprayer.

2. Application of the insulating stucco, up to 6 cm in thickness, in one operation, by hand or by machine.

3. Application of a finishing coat, which must be compatible with the insulating stucco, ususally mineral-based, which comes in different types of grain, textures and light colours. Depending on the system, a smoothing coat is applied prior to the finishing coat. Sometimes the finishing coat is also painted. As a rule, only mineral-based mortar is used as finishing coat. Organically based or organically-enriched finishing coats should be used only if their properties have been especially adapted and tested for the system involved.

Application

Insulating stuccos have a coefficient of thermal conductivity of 0.05 W/mK to 0.099 W/mK. Stuccos with a k-value of 0.1 W/mK or better are called light stuccos or light mortars.

Insulating stuccos or plasters can be applied as exterior and interior insulating to all types of masonry, or to existing mineral stuccos or plasters in old buildings if they are sound.

However, if they are the only insulating layer of an exterior wall they are relatively inefficient. Their insulating value is one to three times smaller than that of a good insulation material such as polystyrene or mineral wool. In the case insulating stuccos with several layers, there is a risk that the layers will separate. Single-layer insulating stuccos should however be applied with a thickness of not more than 5 -

6

&I.: .. : ,•• : .... ',_

finishing coat insulation stucco cement pre-spray

Installation Preparatory work

The base must be dry and clean. Old stucco must be pretreated in such a way that the insulating stucco will adhere to it. Paint and synthetic-resin stucco coats have to be removed. Existing stucco coats with insufficient strength must be completely removed. Light-weight woodwool slabs, joints between different materials, wood or steel beams must be reinforced by mesh. For corners, seams and joints specially galvanized metal supports are available.

Such supports are available for stucco thicknesses of 2 cm - 10 cm, and there are three different types: 135°, 110°, and 90°. These supports are either spot-glued with adhesive plaster every 30 cm, or even better, fastened with dowel-screws to the rough masonry or the existing mineral plaster base.

Installation principles

Insulating stucco should preferably be applied in one layer. To achieve a specified thickness it is best if the stucco is about 0.5 - 1 cm thicker when applied. Each plaster layer must harden sufficiently before the next coat is applied. The finishing coat should not be applied earlier than 2 weeks after the insulating stucco has been applied. No stuccoing should be done at temperatures under 5°C. If the finishing coat is to be painted, this should not be done earlier than 2 weeks after the finishing coat has been applied.

Interfaces

Where the stucco connects with wooden or metal parts, and where water could penetrate behind the heat-insulation layer, sealant joints should be provided. Underground seams should be avoided or if unavoidable, protected with a suitable material (silicon, bitumen).

Insulating stucco can be successfully applied even to so-called difficult bases by means of metal lath or expanded metal fabric, (evg , wooden beams, change from one base to another, etc.). By embedding a glass fibre mesh in the outermost layer, it is possible to apply stucco to bases which may change from masonry to concrete, or from one type of masonry to another or which may have areas subject to cracking.

Important Pointers

No vapour barrier is necessary when using exterior insulation.

When using interior insulation, it must be calculated how the vapour diffusion will occur.

When insulating stucco is painted, the paint must be permeable to vapour diffusion but repel rain.

As a rule, organic coats cannot be applied as a finishing coat. Insulating stuccos must be mixed by machine. The mixing time should not exceed 2 minutes per batch.

Insulating stuccos should not be applied thicker than 5 - 6 em but on the other hand should not be thinner than

3

Tenders

The following information should be included when tenders are called: existing base,

required k-value in W/m2K or thickness of insulating stucco, type, structure and grain size of finishing coat,

See also eRB standards catalogue, NPK No. 119, 1979, item 300: Insulating stucco.

Products

Information about the sUitability of products can be obtained from:

product list "Thermal Insulation Materials", Application Area ALl,

results of comparative tests under the Incentive Program carried out under the sponsorship of EMPA,

INFORMATION SHEET

Walls: Interior Insulation Insulation using Composite Board System

Composition

212.1

Composite board consists of an insulation material and a protective outer layer that sometimes acts as a stressed skin. The sheets are fastened directly to the existing construction (glued or mechanically fastened). If the base is uneven, they are installed with spacing-bolts or on a levelled wooden frame. In the case of wooden walls, a wooden frame or at least slats to overcome shrinkage effects are required.

Insulation materials

Insulation materials used may be rigid foams, mineral fibre, or soft fibreboard, The skin material can be plasterboard, wood-wool board or hard fibreboard. Insulation thicknesses of 6 - 10 cm are recommended.

Vapour barrier

A vapour barrier is usually necessary for: air-conditioned interior rooms,

vapour-tight exterior walls, such as concrete walls,

vapour-permeable heat insulation materials, such as mineral fibre board.

The vapour diffusion behaviour of the construction should be analyzed.

cork strip

...B - - bonding-mortar

m ...- -composite board such as

Installation Preparatory work

The existing construction must be dry and structurally sound. If the glueing method is used, the existing plaster must have adequate strength and adhere well to the base. Wallpaper and paint must usually be removed. Plumbing and heating pipes in the existing construction must be insulated or relocated to

the warm side.

To prevent surface condensation along uninsulated concrete ceilings, a heat insulation strip about 50 cm wide and 1 - 2 cm thick should be installed on the ceiling along the exterior wall. Insulation strips of greater thickness are impractical, since this would only shift the problem of cold surface temperatures further inside.

Installation principles

Composite board with gypsumboard:

Gypsumboard (about 50 cm x 100 cm) should be tongue-and-grooved all around. The sheets should be arranged in a bond pattern, finger-jointed at the corners. To prevent cold-bridges in the corners, the finger-jointed sheets are not butted directly into the corners but laid against an insulation strip so that the board does not touch the cold exterior wall. The space between the composite board and the ceiling or wall should be filled with insulation and plastered over with mortar to which gypsum is added. In case of wooden constructions, the sheets are fastened mechanically.

Composite board with gypsum wallboard:

The size of sheets must be such that a single sheet can cover the entire height (up to 260 cm) of a room. The sheets are glued spot-glued or strip-glued (distance between spots or strips about 30 cm) , Joints between sheets must be smoothed over with a joint sealer.

Composite board with wood-wool board:

These sheets are available in large formats (up to 300 cm long) and small formats. In case of solid walls, the sheets can be glued. In case of frame construction, they should be bolted or fastened with gyprock nails. To prevent cracks, the joints between the sheets should be covered with a mesh.

Composite board from wood products:

These boards also are available in large-format sheets. They can be either glued or nailed to wooden slats or installed by means of spacer bolts. Joints between sheets should be tongue-and-grooved and glued.

Connections

Rigid connections between composite board and adjoining structural elements, particularly flat-roofs should be avoided. For this purpose appropriate small gaps should be left.

If composite board made from wood products is used dimensional changes due to shrinkage and expansion of about 0.2% should be expected. This should be taken into account in designing the connecting joints.

Composite board should never have any air spaces behind and therefore all openings for plumbing and other pipes should flexibly and hermetically sealed.

Gypsum board sheets should be set down on a strip of compressed cork.

Important Pointers

Rigid foam composite board unfortunately tends to reduce longitudinal sound insulation of the exterior wall. If this is critical, mineral fibre insulation should be used.

22

-When sheets are not abutting properly, or if adhesives form a continuous mass in the joints, this results in a heat-bridge. Such joints will show on the surface. Gaps in the heat insulation layer in corners and edges should be avoided.

Tenders

The following information is essential when tenders are called: existing construction,

required type of composite board, thickness of insulation and of support, desired final surface (paint, wallpaper, etc.),

height of wall,

connections and openings.

Products

Information about the suitability of products can be obtained from:

product list "Thermal Insulation Materials", Application Area A2, B2, results of comparative testing carried out in the course of the Incentive Program sponsored by EMPA,

Swiss Association of Master Cabinetmakers and Furniture Manufacturers (VSSM), Zurich,

INFORMATION SHEET

Walls: Interior Insulation Insulation Behind Masonry System

Composition

212.2

In the case of insulation plus interior plastered masonry, the insulation is first applied to the existing construction, then, if necessary, a vapour barrier is installed and in front of that, a wall of masonry units or slabs is constructed. Depending on the type of masonry, plastering or a mere surface finish (paint, trowel coat) is required.

Insulation materials

Most insulation products available in sheet form are suitable for this purposes.

In the case of vapour-permeable insulation materials, an integral vapour barrier is desirable.

A thickness of insulation of 6 - 10 cm should be aimed for.

Vapour barrier

In the case of vapour-permeable insulation materials such as mineral fibre products, with air-conditioned interior rooms or vapour-inpermeable exterior wall parts, the need for a vapour barrier should be analyzed. Vapour barriers of aluminum must not, because of corrosion problems, be in direct contact with the mortar of the masonry. In the such cases, a plastic-coated vapour barrier or a film such as polyethylene must be used. When the insulation consists of rigid foamed that is relatively vapour-tight, a vapour barrier may not be necessary. In doubtful cases, a specialist in building physics should be consulted. Foamed glass is vapour-tight and requires no vapour barrier.

/ / . , . . . . : 1- '1(, ,,' • -• • • • • - « •

'-'I" .•.... - "

.

compressed cork strip styrofoam strip -- thermal insulation 'vapour barrier '-- masonry cladding ' - plaster Installation Preparatory work

The floor must be even and able to support the added weight of the masonry cladding.

If the floor is uneven, a bed of mortar should be provided. The masonry

cladding should be erected over a strip of compressed cork. Plumbing and

heating pipes in or on existing walls should be insulated or re-laid on the warm side.

Installation principles

The thermal insulation sheets must be applied to the existing masonry with a suitable adhesive. If a vapour barrier is installed, the joints should be overlapping by 10 cm and covered with sealing tape.

25

-Cladding consisting of gypsum slabs:

Depending on the height of the wall, the following slab thicknesses can be used: height of wall 3II 3 m 4 m 5 111 slab thickness 4 em 6 em 8 em 10 em size 50 x 100 em 50 x 66,6 em 50 x 66,6 em 50 x 66,6 em

The sheets are laid in a bond pattern. The joint between the cladding and the ceiling or wall should be plastered over with a special mortar to which gypsum is added. The frost-proofing along the ceiling must be separated by means of a soft material. After smoothing, the surface can be treated directly (paint, trowel-finish) •

Interior cladding consisting of hollow clay tile of bricks:

The thickness depends on the product. To prevent cracks in the plaster, the masonry cladding should be as thick as possible (at least 7.5 cm) which is also an advantage regarding sound insulation. In the case of very high ceilings, the masonry cladding may have to be anchored to the existing construction.

Connections

Connections of plumbing and other pipes should be flexibly and hermetically sealed.

This interior cladding should not carry the load of any adjacent constructions, such as ceilings or walls, since this would lead to cracking. For that reason, appropriate joints or at least semi-cuts are required in the plaster.

26

-Important Pointers

If placed on an uneven floor or base, the cladding may crack. In damp rooms, ciadding should not consist of gypsumboard.

Because construction and plastering are not a "dry" construction process, cladding made of hollow clay tile, etc. is more suitable for total renovations where the premises are not used for some time.

Tenders

The following information should be included when tenders are called: existing construction,

type of masonry cladding, thermal insulation, and, if necessary, vapour barrier,

type of interior plastering, nature of finished surface, height of wall,

connections and openings.

Products

Information about the suitability of products can be obtained from the following:

product list "Thermal Insulation Materials", Application Area A2,

results of comparative testing carried out in the course of the Incentive Program sponsored by EMPA,

Swiss Association of Master Painters and Plasterers (SMVG) , Zurich, Swiss Association of Architects (SBV), Zurich.

INFORMATION SHEET

Walls: Interior Insulation Insulation behind cladding System

Composition

212.3

As a rule, the insulation is installed between wood or metal furring members and then covered. Sometimes it is also possible to glue the insulation continuously without gaps and to fasten the cladding in front of i t with spacer-bolts. The cladding may consist of large-format sheets, such as gypsum wallboard or particleboard, or of wood panelling.

Depending on te nature of the construction, a vapour barrier or vapour retarding layer may be necessary between the insulation and the cladding.

Insulation materials

Various materials are suitable in the form of sheets or batts:

polystyrene, mineral fibre, cork, chipboard, etc. or mineral fibre batting with a laminated vapour barrier. Insulation thicknesses of 6-10 cm are recommended.

Vapour barrier

When vapour-permeable insulation materials such as mineral fibre are used, a vapour barrier is desirable. Rigid foams are relatively vapour-tight and do not require a vapour barrier except in rooms with high humidity (kitchens, bathrooms, air-conditioned rooms) or in the case of vapour-tight exterior walls (concrete walls).

D-It---furring rto.4+--- insulation ｾｈＭＭＭＭｶ｡ｰｯｵｲ barrier I"k:IMf---cladding Installation Preparatory work

The existing construction should be dry and structurally sound. Plumbing and heating pipes in the existing construction should be insulated or re-laid on the warm side of the insulation.

Installation principles

The insulation should either be pressed with the vapour barrier toward the warm side between supports, glued or mechanically fastened.

Cladding with gypsum wallboard:

Sheets should be of such a size that a single sheet can be used for the entire height of a wall (up to 260 em). The sheets are fastened to the supports, and

joints should be finished over.

Cladding with chipboard:

Sheets can also be cut so they cover the entire height of a wall. The tongue-and-groove joints should be glued and finished over. Length changes of up to 0.2% due to shrinking and expanding can be expected. Appropriate gaps should therefore be provided at the joints.

Cladding with wool-wool board:

The sheets should be arranged in a bond pattern. If they are plastered subsequently, they must be covered with mesh. Prior to the first coat of plaster, a coat of cement mortar should be applied.

Cladding with wooden panelling:

Wooden panelling should be fastened to the furring with staples or nails.

Connections

The cladding should not be squeezed between adjoining constructions, since this may cause cracks. Appropriate gaps should be provided.

Connections with plumbing and other pipes and openings should be flexibly and hermetically sealed.

Important Pointers

In damp rooms the cladding should not consist of gypsum wallboard. If the insulation is also to provide soundproofing and fire protection, mineral fibre insulation should be used.

Often the deflection of concrete ceilings is not SUfficiently taken into account. This often causes cracks at the joints.

Tenders

The following information is essential when tenders are called: composition of the existing construction,

required k-value in W/m2K, or insulation thickness, type of cladding,

connections and openings, height of wall.

Products

Information about the suitability of products can be obtained from:

Product List "Thermal Insulation Materials", Application Area A2, B2, results of comparative testing under the Incentive Program sponsored by EMPA,

Swiss Association of Master Cabinetmakers and Furniture Manufacturers (VSSM), Zurich,

INFORMATION SHEET

Roofs: Sloped Roofs

Interior Insulation for Sloped Roofs System

Suitability

221.1

This system is sui table only for roofs with an existing and intact sub-roof,

specifically when only parts of a roof are to be insulated. Interior

insulation of roofs requires a sub-roof. Sub-roofs installed later from the

inside are risky. This system is also unsuitable when the rafters are to

remain visible.

Structure

The insulation is applied, with a vapour barrier or vapour retarder on the

inside, either between or under the rafters. A ventilated space must be

provided between insulation material and SUb-roof, if no vapour barrier is

used or in case of extreme climates. It is very important that the entire

roof area and all connections be absolutely wind-proof.

separate wind seal should be installed.

Insulation materials

If necessary, a

For this type of insulation, mineral fibre batting is commonly used because of

its adaptability. The width of the batts corresponds to the most common

distances between rafters. In addition the paper or "Alukraft" covering

provides a wind-proof skin. Also on the market are flame-resistant rigid

foamed sheets which can be fitted between rafters by cutting. However, they require a separate wind seal, since the fitting cannot be made Wind-proof.

For foamed-in-place roof insulation, the commonly used material is

urea-formaldehyde.

Insula tion thicknesses of 10 cm or more should be used in order to reach the recommended k-value of

0.3

Vapour barrier

In general, a vapour barrier or vapour retarder is recommended. However, this is not essential if sufficient ventilation is provided between the insulation and the sUb-roof, and if only rooms without much dampness (i.e. no bathrooms, kitchens, etc.) are situated in the attic. The ventilation space should be 4-10 em, the exact amount depending on roof slope and length. for special problems, a specialist in building physics may have to be consulted.

Installation Preparatory work

The wood construction should be checked for any dampness, dry rot and insect damage, and repairs should be carried out where necessary. The sub-roof must be checked for water-tightness. If there is no sub-roof, a sub-roof should be installed continuously over the rafters.

Installation principles

Version A

The batts (rolls, usually with a laminated vapour barrier) are pressed between the rafters and fastened to these with lathing. When the insulation batts are thicker than 8 em, this type of fastening becomes difficult. Direct fastening with staples is impractical (because of insufficient rigidity and density, and because the laminated vapour barrier might tear). The width of the rolls should correspond to the distance between rafters plus 8-10 em. If the insulation material does not have a vapour barrier, a film may be applied. But because of the high risk of damage to the film i t should quickly be protected by a covering.

1. roofing 2. sub-roof

3. insulation batt 4. insulation batt with

laminated vapour barrier and installation tabs

5. vapour barrier 6. cladding

7. foamed-in-place insulation 8. existing plaster ceiling B version 3 4 5 Ｖｾｾｾｾｾｾ A version 7 3

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_C.D

Batts with laminated aluminum vapour barrier and installation tabs along the sides are pressed between the rafters. The installation lips are stapled to the underside of the rafters, and the stapling lip is taped over with special tape. In the case of a finished attic, the insulation is covered by some cladding.

Version C

In the case of very thick insulation it is recommended to install the insulation material in two layers. The first layer (felt roll without vapour barrier) is laid between the rafters, and then cross-furring is fastened over the rafters. The distance between laths should correspond to the width of the insulation batts (with vapour barrier and installation lips). The installation lips of the second layer are stapled on the horizontal cross-furring. Hollow spaces between the two insulation layers should be avoided.

Version D

If the ceiling height in the attic is of no consequence, the entire insulation can be installed below the rafters. This solution would be preferred mainly when the rafters are spaced very irregularly. This makes i t much easier to attach the insulation to the rafters. As in the case of the second layer of version C, a horizontal furring is fastened to the rafters, the batts are laid between, and the installation lips are stapled to them. If no additional covering (such as wood panelling) is required, special hangers which are stapled to the rafters can replace the cross-furring. With this version, mineral fibre sheets with laminated vapour barrier are used instead of the

felt rolls. The insulation sheets are pressed against the rafters, and the tabs of the hangers are bent over. The butt joints are sealed with aluminum tape.

Version E

Another possibility is to foam the space between sub-roof and inside cladding in place with urea-formaldehyde foam (UF). Since this actually eliminates the ventilation of the sub-roof, this solution should only be used under certain conditions and in cases where conventional solutions are too expensive. This solution is not suitable for extreme climatic conditions. This solution is also unsuitable for relatively vapour-tight SUb-roofs (tar paper, film) which could prevent the drying of the foam, and for damp rooms without vapour barrier on the inside. Normally it is impossible to install an inside vapour barrier.

To foam an entire roof, a vapour-permeable, continuous SUb-roof (wood shingle sub-roof, GA-sub-roof, et c , ) is necessary. The insulation value of foam is excellent. But the quality of the insulation layer depends very much on the

•

workmanship. Such work has to be carried out by experts. The foam is produced in place and sprayed into the air space by means of small drill holes at distances of about I m. It solidifies after approximately 30 minutes.

Connections

Attention should be paid especially to all connections, particularly between the insulation and end rafters and sills. Problems can also occur at headers, intermediate purlins and ridge purlins. These connections must be carefully planned and executed because a hermetical seal is necessary.

Good seals are mainly necessary to prevent warm inside air from escaping to the outside and causing condensation in the sub-roof.

Ventilation between insulation and sub-r-oof' is ensured only when there is a sufficiently large air inlet opening under the eaves and an outlet opening at the ridge that is about 25% larger than the inlet opening.

Tenders

The following information is essential wnen ｴ･ｮｵｾｲＺＩ are called:

existing construction: depth of rafters, length of spaces, spacing of rafters, sub-roof,

desired construction: insulation thickness and material, vapour barrier, air seal, cladding,

openings and connections.

Products

Information about the suitability of products is available from:

Product List "Thermal Insulation Materials", Application Area D2,

the results of comparative testing under the Incentive Program sponsored by EMPA,

Swiss Wood Council (LIGNUM), Zurich,

Swiss Association of Master Roofers (SDV), Niederuzwil, Swiss Association of Master Carpenters (SZV), Zurich,

Swiss Association of Master Cabinet Makers and Furniture Manufacturers (VSSM) , Zurich.

INFORMATION SHEET

Roofs: Sloped Roofs

Exterior Insulation for Sloped Roofs System

Composition

221.2

•

This system requires the total removal of the roofing down to the sheathing or rafters. Vapour barrier, insulation and sub-roof for the new roofing can be applied either in individual layers or as a complete sub-roof.

Four basic versions are possible within this system:

1. roofing 2. sub-roof

3. seamless sub-roof membrane 4. thermal insulation 5. insulating sub-roof 6. vapour barrier/retarder 7. sheathing ,-·version A version

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A. Version with vented sUb-roof

This solution is suited to situations that are particularly demanding in terms of building physics and climate. Instead of a vapour barrier, a wind seal functioning as vapour retarder may suffice under certain circumstances. Mineral fibre board is the most suitable insulation material. Depending on roof slope and length, the depth of the vented space should be 4-10 em,

Rigid, self-supporting materials must be used for the sub-roof.

B. Version with sub-roof membrane

Because in this solution there is no ventilation behind the insulation material, a vapour barrier must always be provided on the inside. Insulation materials used are often compression-resistent, non-shrinking polystyrene foam products. Furring that is fastened through thick insulation layers requires particular attention, especially when high winds and heavy snow loads can be expected. Sometimes the insulation material can have integrated furring. Plastic membranes (non-perforated) or asphalt sheets are suitable for sub-roofs, but they must have a greater vapour permeability than the vapour barrier.

c.

Since the sub-roof is below the insulation layer, the insulation must be non-water-absorbent. The fastening of the furring through thick insulation layers again is difficult. Wooden parts should not be integrated in the insulation material, since there is a danger of rotting. This means that one should choose a rigid foam that is as strong in compression as possible (p ｾ

30 kg/m3 ) . With this system, the SUb-roof must be seamless.

D. Roof construction with an insulating sub-roof system

The insulating SUb-roof consists of composite elements comprising a wateproof membrane and an insulation layer available in different thicknesses. The composite element is laid either onto existing sheathing or directly onto the rafters. Depending on the system, the composite elements also have a laminated vapour barrier and integrated furring. A separately laid continuous vapour retarder or vapour barrier is an advantage, however, and may also serve as wind seal. Insulating SUb-roof systems are a relatively recent solution, and long-term experience is still lacking. Such systems are mainly intended for moderate climates.

Insulation materials

The insulation materials that can be used were described above in the section entitled "Structure". In addition regulations must be taken into account, especially for version C.

Insulation thicknesses of 10 em or more are recommended, so that the k-value of 0.3 W/m2K can be achieved.

Installation Preparatory work

The old roofing including furring and cross-furring must be removed. The eXisting sheathing and beams must be checked for damage by dampness, mould and insects, and repaired if necessary. An shingled SUb-roof is not suitable as a vapour barrier and should be removed since otherwise the vapour barrier might be damaged by the protruding edges.

Installation principles Version A

The vapour barrier, or retarder, is laid in sheets over the solid base (wood sheathing, chipboard), the joints are overlapped and sealed; all connections are made windproof. New furring is installed over the rafters (furring height plus insulation thickness should be at least 4 em), the insulation batts are pressed between, and a new sub-roof, cross-furring, battens and roofing are laid over this.

Version B

The vapour barrier is laid in sheets over the smooth base, the joints are overlapped and sealed. Then the butt-jointed insulation boards and the seamless sub-roof film are laid. Over this, the cross-furring is fastened to the rafters with special nails (holes must be predrilled in the furring insulation). The nail holes thrOUgh the plastic film are sealed with a special sealer. Sometimes the cross-furring is additionally fastened in the ridge area and along the eaves for more strength.

Version C

The membrane is laid directly onto the smooth base and sealed. Note that shingled sub-roofs are not suitable as a base because of the risk of damage to the membrane along the edges. This membrane also serves as vapour barrier. All connections should be windproof. The insulation boards which must be non-compressible and non-water-absorbent are laid and fastened with nails to the cross-furring along the rafters. Since the nail holes through the sUb-roof membrane cannot be sealed, asphalt sheets such as v-60 are particularly well-suited for this system. In this case, too, it is advisable to inter-connect the cross furring in the ridge area and at the eaves for additional strength.

Version D

The installation varies depending on the product and the manufacturers' instructions should be followed. It is particularly important that the individual boards be laid as closely butted together as possible (in the case of mineral fibre, the fibre should actually be in termeshed) , in order to achieve a construction that is as windproof as possible. It is always advisable to apply the sheathing over the rafters, to get a good base for the sub-roof system, and as an additional air barrier. Also for this system, the roofing material should always be laid over furring and cross-furring.

Details

The best details will always depend on the product used. Connections in the ridge area and on the eaves and end rafters must be carefully planned and executed.

Important Pointers

The impermeability of the vapour barrier be greater than that of the waterproof covering.

The best way of fastening of the cross-furring for relatively thick insulation and large roofs, must be determined carefully. In some cases, furring integrated in the insulation material can be used, but this always requires a sub-roof on top.

The vapour barrier should be made as airtight as possible to prevent moist indoor air from escaping to the outside and forming condensation on the cold side.

Tenders

The following information should be provided when tenders are called: existing construction,

required sUb-roof, thickness of insulation,

required additional construction elements (sheathing, vapour barriers), required connections.

Products

Information about the suitability of products is available from:

Product List "Thermal Insulation Materials", Application Area Dl,

the results of comparative testing under the Incentive Program sponsored by EMPA,

Swiss Wood Council (LIGNUM), Zurich,

Swiss Association of Master Roofers (SDV) , Niederuzwil, Swiss Association of Carpenters (SZV), Zurich.

INFORMATION SHEET

Roofs: Flat Roofs

Insulation by Means of an Added Upside-Down Roof System

Composition

222.1

In the upside-down (protected membrane) roof, the membrane lies below the

thermal insulation. It is thus located in an area of low temperature

fluctuations and is protected from mechanical damage during installation and when in service. In this system, in order to improve the thermal insulation of an existing conventional roof, an additional insulation layer is laid on top of the cleaned existing membrane and weighted with a protective gravel layer. The insulation and the protective gravel layer are separated from each other by a plastic mesh.

This type of insulation is suitable for flat roofs whose membrane and metal flashings are intact. I t is not suitable for roofs with damaged cladding or

corroded terminal plates. Upside-down roofs can be built with or without

slope. The great advantage of additional reverse roofs is that often the

flashings do not have to be adapted.

Insulation layer

Such a roof requires a non-decaying, weatherproof and walk-on insulation

material that absorbs very little water even over long periods of time.

Practical experience has shown that only extruded polystyrene foam meets these requirements. This material is characterized by a closed-cell structure and, if certain rules are followed, by very low water absorption. Depending on the

width of flashings and existing insulation, thicknesses of up to 12 cm

insulation can be used. The thickness of the new insulation should also

preferably be such that the temperature of the roof membrane does not fall below freezing. To compensate for the heat loss caused by the water flowing off on top of the membrane, the thermal resistance of the insulation should be chosen about 20% greater than that of a corresponding conventional flat roof with the membrane on top of the insulation.

Protective gravel layer

As protection against UV-radiation, but. also to counteract wind suction and buoyancy, the Insulation must be covered with gravel (grain size 16/32 mm). The thickness of the protective gravel layer depends of the thickness of the

insulation.

thickness of the insulation thickness of gravel

over the roof cladding

0-6 em 6 em

8 em 7 em

10 em 8 em

12 em 9 cm

The existing gravel-sand mixture of the existing roof may be reused as a

protective layer.

When rather thick insulation is added to a norr-gr-ave l l ed existing roof, the structural capacity of the roof should be checked, i.e. it must be determined whether the additional load is permissible.

protective gravel layer ＭＭＭＭｾｳ･ｰ｡ｲ｡ｴｩｮｧ plastic mesh

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__ existing roof membrane

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Installation Preparatory work

The existing gravel layer is removed in stages. One must not deposit the entire amount of gravel in one place, as for example in the middle of the roof, since this could exceed the local carrying capacity of the roof floor. Clean and carefully wash the roof membrane.

To check the membrane it is recommended to make sample openings every 10 - 20 m. If the insulation is wet, the entire membrane and insulation should be replaced. If the flashings are corroded, they must be replaced and the membrane around them renewed. In the case of one of the newer roofs made of plastics, the welded seams in particular should be checked.

In case of an existing black-top roof, it is often advisable to install, prior to laying the insulation, an additional asphalt finishing coat plus membrane or perhaps a plastic sealer over a special mesh.

Installation principles

The extruded polystyrene foam boards are butt-jointed and laid on the roof membrane with staggered joints. Over the boards a separating layer of vapour permeable and non-decaying plastic mesh is applied. The gravel layer is spread over the separating layer.

On walk-on roofs, the patio slabs should not be laid directly over the separating layer. They should either be layed on gravel chips or over spacers.

Connections

The connections with flashings and expansion boxes should extend about 10 - 12 em above the new level of the walk-on roof or protective layer. Since this is often impossible, one solution is to reduce the thickness of the insulation along the sides over a width of about 50 em (see figure above). To prevent major stresses in the roof membrane, however, insulation of at least 2-3 cm in thickness should be laid along the sides.

If the gravel layer has a slope the gravel will tend to shift. Cement or synthetic-resin "gravel solidifiers" can be used, but this is sometimes problematic. A better solution is to use angles which are laid on spacers along the roof edge and keep the gravel back. Leaf screens at roof drains should also be adapted to the new height.

Important Pointers

Only vapour permeable materials should be used for the separation layer. Perforated plastic film sufficiently vapour permeable and should not be used.

If the additional upside down roof applied on top of a plastic film roof consti tutes an insulation value of 2/3 or less of that of the existing roof construction, a separating layer should be laid between the plastic film and the polystyrene insulation. This will prevent a possible softening and creep. This does not apply to ordinary upside-down roofs.

Whether the existing sand and gravel layer can be left on the roof during the renovation depends on the strength of the building and on the size of the area. It is often less work to remove the mixture of sand and gravel from the roof during the work. Quite often the existing gravel is badly soiled, in which case it is better to use new gravel.

In the case of an ordinary (not an added) upside-down roofs it must be remembered that the rain water that penetrates through the gaps in the patio slabs and flows along the roof membrane removes heat. In wood or steel plate constructions, the surface temperature on the warm side can decrease so much that as a result surface condensation occurs. Therefore, true upside-down roofs should only be used on concrete slab roofs.

Tenders

The following information is essential when tenders are called: existing roof construction,

required k-value or thickness of insulation layer, flashings, connections to other building elements, adapting of roof drains,

checking roof cladding, existing insulation and connections,

contractor's warranty (normally the contractor guarantees the proper functioning of the entire roof construction).

Products

Information about the suitability of products is available from:

Product List "Thermal Insulation Materials", Application Area E 1.1,

the results of comparative testing under the Incentive Program sponsored by EMFA,

Floors and Ceilings: Attics Floors Attic Insulation, Non-Walk-On Type System

Composition

INFORMATION SHEET

231.1

The insulation is laid without joints on the upper side of the ceiling (e.g. in an attic) i.e. the insulation forms the top layer and cannot be walked on.

rafter edge member top plate insulation

r---

Suitable as insulation materials are all good quality materials such as mineral fibre batting or sheets, cork, organic foam products, expanded mineral products, wood fibre products with ａｾ 0.06 W/mK, etc. Since the insulation material has no support function, products low density are suitable. The optimum economic insulation thickness is around 8 - 12 em.

Vapour barrier

Generally no vapour barrier is necessary. But there are insulation materials which already have a vapour barrier attached. It is essential that this be

placed on the warm side of the insulation.

Installation Preparatory work

Ceiling constructions made from wood joists, and also existing insulation materials, should be checked for damage and possible dampness and insect infestation. In the case of attics, it is important that the roof be waterproof, so that the insulation will not become wet. Possible air passages in wood joists ceilings must be filled. If there are many areas where air can escape, a continuous overlapping film of polyethylene can be laid under the heat insulation.

Installation principles

Batts are rolled out, sheets are laid, loose material is spread evenly across the ceiling. It is essential that the individual insulation batts or sheets are carefully joined together to prevent unwanted air circulation below the insulation. In some cases, the insulation may have to be spot-fastened or weighted down.

When several insulation layers are applied, the joints should be staggered. The upper layers must not have any vapour barrier.

Connections

All connections with exterior walls, roof constructions, chimneys, etc. must be executed carefully. In particular, the insulation must be laid to the outer edge of the construction (flush with the ｦ｡ｾ｡､･Ｉ［ in some cases the top plate of the eaves may have to be included.

Important

If an existing insulation layer is added to, attention must be paid to the vapour permeability of the insulation material that is used. The new layer must not be more vapour-impermeable than the existing layer. If a combustible insulation material is used, permission of the fire insurance company must be obtained beforehand.

Tenders

The following information should be provided when tenders are called: existing construction,

working conditions (e.g. accessibility),

desired insulation thickness, if required the covering for insulation, connections with existing constructions.

Products

Information about the suitability of products is available from:

Product List "Heat Insulation Materials", Application Area H 1.1,

results of comparative testing under the Incentive Program sponsored by EMPA,

Swiss Wood Council (LIGNUM), Zurich,

Swiss Association of Master Cabinetmakers and Furniture Manufacturers (VSSM), Zurich.

INFORMATION SHEET

Floors and Ceilings: Attic Floors Attic Insulation, Walk-On Type System

Structure

with insulation material of load-bearing capacity:

231.2

The insulation boards but ted together as close to each other as possible. Loose insulation should be spread evenly and compacted. Over the insulation layer, a walk-on covering is laid (e.g. chipboard, gypsum wallboard, decking).

- compression-resistent

or concrete slab construction

with insulation material on non-load-bearing capacity:

First furring members are bolted to the construction, then the insulation is laid flush between them, and a walk-on covering is laid over everything.

ｾ covering

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Insulation material

Most good quality thermal insulation materials are suitable. For insulation to be load-bearing, adequate rigidity is important, and this should be determined beforehand. With mineral fibreboard the density should be at least 100 kg/m

3,

3•

Vapour barrier

No vapour barrier or vapour retarder is necessary for dry constructions. If plasterboard is used as a walk-on surface, the manufacturer should be consulted re the need for a vapour barrier. If the insulation material comes with an attached vapour barrier, it must be placed on the warm side (bottom).

Installation Preparatory work

The existing floor must be dry and clean. For newly constructed concrete slabs, a dampness test is recommended. When rigid foam or composite board is used, the floor surface should not have any major unevenness so that the boards will adhere completely.

Installation principles

If the insulation consists of two layers, the joints should be staggered. The upper layer should not have a vapour barrier. Along the edges (at gable walls, sills) the covering should be laid with an adequate gap to allow for expansion, e.g. 0.2% of the room dimensions. To achieve better sound insulation against footstep noise, a reinforced concrete subfloor could be installed with a separation layer against the insulation. A separation layer should also be installed between loose insulation and walk-on covering.

51

-Connections

Connections to gable walls, sills, chimneys, etc. must be as tight as possible so that the insulation is not circumvented by air currents which would reduce its effectiveness. This is particularly important in the case of rigid insulation boards. In the case of composite board, the end joint must be plugged with loose insulation. The joints of sheets forming the walk-on covering may also have to be sealed.

Important

If combustible insulation materials are used permission of the fire insurance company must be obtained beforehand.

Tenders

The following information is essential when tenders are called: existing roof constructions,

working conditions (e.g. height of working space, accessibility), connections with existing constructions,

expected load on the covering, sound insulation requirements.

Products

Information about the sUitability of products is available from:

Product List "Thermal Insulation Materials", Application Area H 1.2,

results of comparative testing under the Incentive Program sponsored by EMPA,

Swiss Wood Council (LIGNUM), Zurich,

Swiss Association of Master Carpenters (SZV), Zurich,

Swiss Association of Master Cabinetmakers and Furniture Manufacturers (VSSM), Zurich,

Floors and Ceilings: Attic Floors

Interior Insulation for Concrete Slab Ceilings System

Composition

INFORMATION SHEET

231.3

The insulation is glued or fastened mechanically to the underside of the ceiling. If furring is used many types of cladding can be chosen (gypsum wallboard, chipboard, panelling, et.c , ) , In the case of suspended ceilings, the insulation can be laid over the suspension system. The vapour barrier must always be placed on the warm side of the insulation.

ｾｾ

Insulation materials

Insulation materials that can (density 40-70 kg/m

3) ,

be used are mineral fibre board or batts foam products 20 kg/m3 ) , foamed glass and

,.

in rare cases cork. Well-suited for installation between furring are batts with vapour barrier on one side and longitudinal, continuous installation tabs. Composite board of gypsum or wood particles in combination with organic foam products (p = 20 kg/m3 ) , or mineral wool (p = 100 kg/m3) have also proven suitable. The optimum insulation thickness is between 8-12 em.

Vapour barrier

When vapour-impermeable insulation such as polystyrene are used in rooms with normal moisture conditions, a vapour barrier is unnecessary. For relatively damp rooms (kitchens, bathrooms, etc.), a specialist should check whether a vapour barrier is required. With vapour-permeable insulation (such as mineral wool), a vapour barrier is necessary. This must always be placed on the warm side of the insulation material. Insulation consisting of foamed glass boards does not require a vapour barrier. Recently composite board with the vapour barrier between insulation and cladding had become available.

Installation Preparatory work

For the glued version the underside of the ceiling must be free of uneven areas, dust and oily residues. The surface should be prepared according to the instructions of the glue manufacturer. Foamed glass should not be glued directly on a surface containing gypsum.

In using furring the thickness of the laths should correspond to the insulation thickness. The lath distance should be 5-10 rom smaller than the width of the board or batts, so that the insulation is slightly compressed.