Publisher’s version / Version de l'éditeur:
Technical Note (National Research Council of Canada. Division of Building
Research), 1968-11-01
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.
https://nrc-publications.canada.ca/eng/copyright
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
NRC Publications Archive
Archives des publications du CNRC
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/20338433
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Fire Tests of Canadian Asphalt Shingles
Rose, A.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
NRC Publications Record / Notice d'Archives des publications de CNRC:
https://nrc-publications.canada.ca/eng/view/object/?id=e72d6c8f-91bd-4fb1-b249-ea0aa54bf1b5 https://publications-cnrc.canada.ca/fra/voir/objet/?id=e72d6c8f-91bd-4fb1-b249-ea0aa54bf1b5DIVISION OF BUILDING RESEARCH
No.
528NOTE
'f
E
C
1HIN II CAlL
PREPARED BYA. Rose CHECKED BY G. W. S. APPROVED BY N.B.H.
DATE November 1968
PREPARED FOR
Inquiry and record purposes.
SUBJECT
FIRE TESTS OF CANADIAN ASPHALT SHINGLES
In 1966 the Fire Section of the Division of Building Res earch learned that exterior fire performance requirements for roofing might be imposed in certain areas in Canada. Construction of apparatus required for testing roofing materials under ASTM Standard El 08 -58 was begun in that year. The original intention was to survey ｴｨｾ per-form.ance of standard 210 -lb shingles from all Canadian plants with the possibility in mind that exterior fire performance requirements might becom.e widespread and eventually be incorporated in the National Building Code of Canada.
When it was learned that the Borough of Scarborough was planning to impose restrictions on roofing, manufacturers shipping into the
Metro Toronto area approached the Section with requests for fire tests on asphalt shingles befor e the survey was well launched. The conditions of acceptance under Scarborough Bylaw No. 13157 are basically those
of U L 790 {liT est Methods for Fire Resistance of Roof Covering Materials, II Underwriters' Laboratories Inc., 1958, for Class C Materials}. UL 790, which differs in minor details from ASTM EI08, is the standard for rating the exterior fire resistance of roofing systems described in the IIBuilding Materials List"of UL Inc. (See Appendixes A and B). Such ratings were originally established at the request of the insurance industry.
2
-The roof testing equipment of UL Inc .• at Northbrook, illinois,
has up to this time been unique. Any ratings of roofing materials
published in the "Building Construction" section of the" List of Materials and Equipment" of Underwriters' Laboratories of Canada have been
based on tests carried out at Northbrook. EQUIPMENT AND METHODS OF TEST
The original DBR equipment was constructed from the schematic drawings and illustrations of ASTM EI08-58, which were obscure in
certain details. Some adjustments and compromises were necessary
in fitting the equipment into the space available. A few errors in design
were corrected and improvements in instrumentation made after a visit to Northbrook in September 1967.
In the early stages of the program propane was used as the
fuel. This necessitated several deviations from the operating conditions
prescribed in E108-58. After a number of tests on American shingles
of known ratings, it was decided that no progress would be possible until natural gas was available.
With the installation of a natural gas line in November 1967,
closer approxim,ation to the required conditions was possible. The
most persistent of the remaining problems were those of air turbulence
and velocity distribution on the test deck and near the burner. These
difficulties were due to the relatively short distance and the drastic changes in section between the 40 -in. propeller -type fan and the "wind tunnel" section of the apparatus.
Turbulence was reduced and uniformity of velocity improved by a reduction in fan rpm, throttling of the fan intake, and installation of two honeycomb stabilizers and a number of deflector s in addition to the vertical fins suggested in EI08.
The E108 and UL 790 standards describe three methods of test. which, in the case of Class C m.aterials, may be summarized as follows:
Method A. Interm,ittent Flame Exposure Test
The flame is applied for three one-minute intervals with two-minute pauses between them, the 12-mph wind continuing during and after flam,e impingem.ent until all flaming ceases or failure occurs.
Method B. Spread of Flame Test
In this test the deck is 13 ft long and 40 in. wide. The flame
is applied for four minutes, then wind and flame are cut off and the
maximum distance of flame travel along the surface estimated. As
in Method A. penetration of the covering, ignition of the underside of the deck and release of flying, flaming or glowing brands, are recorded.
Method C. Burning Brand Test
In this test, the 40 - by 52 -in. deck is moved to a position 5 ft
from the mouth of the wind tunnel. Clear, oven-dried white pine
brands, 25/32 by 1 1/2 by 1 1/2 in. in size are ignited over a gas
burner and placed on the deck at one to two-minute intervals.
Twenty-five brands are placed on the most vulnerable areas of the deck. The
12 -mph wind is maintained throughout the test. Ignition of the
under-side of the deck. production of flaming or glowing fragm ents of roofing, and exposure or disintegration of the deck are recorded.
After the changes in the DBR equipment mentioned above and
minor adjustments to the burner, the required wind velocity (12
1:
0.5m,ph at three points on the I Idum myI I deck) and gas flame tem,perature
(1300 ｾ 50 deg F at the centre of the top of the eave) were established.
The pattern of charring produced on shingles, even when flame travel up the 13-ft deck was 8 ft or more, was symmetrical and well del1neated
Some deviations from ASTM E108 and UL 790 were considered reasonable, particularly in such matters as the species of lumber used
in construction of the test decks. Kiln-dried Douglas fir (Grade D or
better) and air-seasoned Eastern white pine (No. 1 Common) were substituted for the Southern yellow pine in the nominal 2 by 4 battens and Western white pine in 3/4- by 7 1/2-in. deck, boards specified in these standards.
All test decks were stored for several weeks at 48 - 52 per
cent R. H., 68 to 70 deg F before application of the roofing. The
completed decks were stored under the same conditions for at least
a week before testing. This conditioning led to a moisture content
of 7. 2 to 8. 2 per cent for the kiln-dried Douglas fir battens and 10. 5
to 12.0 per cent for the air -seasoned white pine deck boards. The
4
-Survey of Canadian Shingle Production
Preliminary tests on a wide variety of Canadian and U. S. -produced shingles, followed by those carried out at the request of manufacturers, indicated that it was a waste of time to carry out the
Burning Brand Test on well-made asphalt shingles. The Intermittent
Flame Test, while bringing out some differences between samples which varied widely in performance in the Spread of Flame Test,
was at best semi-quantitative and difficult to interpret. The latter
test was considered the only worthwhile one for purpos es of the survey.
All tests on prepared roofing (shingles or roll products) under ASTM E108 are carried out at a slope of 5 in. rise per horizontal foot, unless otherwise agreed upon by the manufacturer and testing agency. This was followed in the DBR survey.
Standard three-tab, 12- by 36-in. shingles were fastened down
by four one-in. roofing nails apiece. The starter course was an inverted
shingle. No felt underlayrnent was used. No effort was made to "cure"
self-sealing shingles in situ, as was done in the case of "official" tests. Shingles tested in this survey were purchased locally on the open market or directly from the manufacturers.
RESULTS
In none of the four-minute Spread of Flame Tests was there penetration of the covering, ignition of its underside, or production of £lying or £laming particles, even in the case of shingles exhibiting
the highest £lame spreads. The essential observations were the
maximum £lame travel on the covering (not the length of £lame front)
and the extent of blackening or fusion of the surface. The tim es at
which the asphalt fir st £lowed and ignited, although not r equir ed, wer e recorded as a m_atter of interest.
The results for 210-lb shingles from fourteen plants in Quebec, Ontario, Manitoba, Alberta and British Columbia ar e
listed in Table
1.
They are grouped by manufacturer but not ine,
TABLE I
CLASS C SPREAD OF FLAME TEST ON 210-LB SHINGLES
No. Type Colour First Flow, Ignition, Max. Flame Max. Blackening,
min. mln. Spread, ft. ft. A-I S. S.':< White O. 45 2.25 4. 3 5.0 A-2 Std. Brown 0.70
1.
30 7.0 9.0 A-3 Std. White 0.701.
40 8. 3 9.8 A-4 Std. Green 0.501.
75 5. 0 6.0 B-5 S. S. Green 0.601.
65 8.0 9. 5 C-6 S. S. Green 0.651.
30 5. 5 6. 5 C-7 Std. Green-
-
7.0 8. 3 D-8 Std. Green O. 701.
65 3. 0 5. 0 D-9 Std. Green 0.651.
90 3. 0 5.3 D-IO Std. Green 0.75 1.75 3. 5 5. 3 D-ll Std. Green O. 701.
60 8. 5 9. 7 E-12 Std. White 0.801.
30 "7.5 9.0 E-13 Std. White 0.601.
30 7. 5 8. 3 E-14 Std. White 0.601.
40 7.5 9.0 *S. S.=
self sealing. DISCUSSIONOf the eight samples with a flame spread of 7.0 ft or higher in
Table I, six wer e from. plants west of Ontario. The two highest
(Nos. A-3 and D-ll) were from. Pacific Coast plants.
Differences in flame spread performance may be due to
differences in raw materials, regional requirements and norrnal
day-to-day variation in quality. Technical representatives of
manufacturers who co-operated in this survey have expressed the opinion that differences in the characteristics of the saturating and coating asphalts are the most important factor.
6
-While the operating conditions in the tests (air velocity, flame temperature, gas consumption) were superficially in reasonable agree-ment with those at Northbrook, it was believed from the outset that this
agreement might be illusory. The many adjustments and mechanical changes
required to obtain the necessary uniformity in air velocity across the test deck might, it was thought, have lead to a real difference in the severity of the test vis -a-vis Northbrook.
Two bundles of shingles from the same shipment as sample A-3
were sent to Northbrook. Their reported flame spread was 11 3/4 ft.
More important, the photographs taken showed a much greater lateral spread of flame as far as 5.5 ft up the deck than did the test at DBR. These disparities may be due to differences in air velocity a short dis-tance above or just outside the deck, however satisfactory the agreement for the three points on the dummy deck prescribed in EI08.
However great the disparity, there is little likelihood that any
210-lb shingle manufacturedinaccordance with such standards as CSA A123.1
- 1964 would fail to meet the requirements of Section 21 (e) of the recently
published Building Code for the North* or Sentence (14) of Bylaw Number 13157 of the Borough of Scarborough (Appendix B).
Improved agreement between the DBR flame spread tests and those at Northbrook on shingles of low, medium and high flame spread will be
the object of the next phase of this work. If such improvement can be achieved
the equipment will be used for research and development work on new roof-ing materials and systems, as well as further tests for manufacturers.
*
Canada, Building Code for the North. National Research Council, AssociateTEST METHODS i-OR FIRE RESISTANCE OF ROOF COVERING MATERIALS
Standard of Underwriters' Laboratories, Inc., (UL 790)
Conditions of Acceptance for Clas sification
At no time during or after the Flame Exposure, Spread of Flame, or Burning Brand Tests shall:
A. Any portion of the roof covering material be blown or fall off
the test deck in the form of flaming or glowing brands, or
B. The roof deck be exposed by breaking, sliding, cracking, or
warp-ing of the roof coverwarp-ing, or
C. Portions of the roof deck fall away.
At no time during the Class A, B, or C Flame Exposure or the
Class A or B Burn,ing Brand Tests shall there be sustained ignition of the
underside of the deck. 1£ ignition does occur, another series of tests shall
be conducted and no additional sustained ignition shall occur.
In the Class C Burning Brand Test, there may be sustained ignition
on the underside of the deck of not more than 20 percent of the 25 brands. At the conclusion of the Spread of Flame Test, the flaming shall
not have spread beyond 6 feet for Class A, 8 feet for Class B, and 13 feet
(the top of the deck) for Class C. There shall have been no significant
APPENDIX B
EXCERPT FROM BOROUGH OF SCARBOROUGH BYLAW NUMBER 13157
(14) Any roof covering that is applied to any house after July 1 st, 1968,
shall be such that, when tested in accordance with ASTM EI08-58, Standard Methods of Fire Tests of Roof Coverings,
(a) no portion of the roof covering material shall be blown off or
shall fall off the test deck in the form of flaming or glowing brands;
(b) the roof deck shall not be exposed by breaking. sliding,
crack-ing or warpcrack-ing of the roof covercrack-ing;
(c) no portion of the roof deck shall fall away;
(d) the spread of flame does not exceed 13 feet and during the
Flame Exposure Test there is no sustained ignition on the underside of the deck, and
(e) during the Burning Brand Test there is sustained ignition on
the underside of the deck or not more than 20 percent of the 25 brands.
The provisions of Sentence (14) shall not apply to the reroofing of any existing house provided the house is reroofed with materials of fire endurance at least equivalent to the existing roofing materials at the time of application.
