E/ CN .141 Asl II/2fj Page 56

is only a broad guide as to "hat might be expected, and a guide on the low ·side. The major ways aluminium can be justifiably used in African construction should be examined.

54.

Looking briefly at the USA, the economies there of using aluminium as a building material have been sO successful that construction has been for some years the leading field for the metal, only recently matched by transportation equipment (led by automobiles). The major

applic~iions

are in sheet for the sides and roofs of buildings --both corrugated and flat with variations in surface treatment and colcur--and in extruded profiles used in making doors, 'windows, colcur--and supporting

framew~rk for panels on the outside and inside of buildings.

55.

In Africa, sheet for buildings may now be the leading use also, and take more aluminium than utensils. In Ghana, out of a possible consumption of some

8,000

short tons of aluminium in

1964,

about

6,000

tons were in corrugated sheet form. In Nigeria out of some

4,000

tons consumed in

1964,

about two-thirds w~re also i~ corrugated sheet, according to Alcan Africa Limited. In other countries of Africa, the proportions of aluminium consumption in building use are eVidently lower. Extrusions are produced only'in South Africa and used only in limited amo'0nts, and imported in _oth~r African countries, usually for government and'commercial buildings.

56. Aluminium has its most obvious economies in government buildings including hospitals and schools, and in commercial bUildings, where it is more _d~able and requires less maintenance than wood and steel, and no painting~ It may not be as appropriate as concrete in North Africa nor in some sections of Africa where concrete roofs are used as catchment basis for water on public buildings. Where labour and transportation costs of materials are important, the lighter aluminium also saves additional costs. OonsaquantLy , if governments and bus.iness _..

establishments would 00nsistently calculate the alternative'costsof building materials over the servioe .life ot: a building, including the ini tiJal costs of the materials a.s.installedand tltecosts of maintenance

' \

J¥'CN .,14/

^AS/

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'1 "

on roofing and· Qutside.

temperaturesduringcj;he and replacement, aluminium in Africa would steadily grow in demand,

" f

particularly in the hUmid areas of Africa.

.. J'.~

57.

For factories and workshops, ~luminium

walls likewise contributes to cooler inaide

" ;~'j " , " "; , , ", ... ' ' , . . ' ,

day and to gr~ater productivity

q;f

J.a;t>0Uf·' ,In parts of Afric" where the nights are cold, the inside surfaCe. of. the aluminium,_{'"e-: ' ,} .. "',)-~ .., ' "-','-' c~~.act as.

a reflector of any interior heat,. >lar~tng the building., '!ihe use of,,;.

- ^{,;.,:, "}

aluminium in this manner >lould no, clmws be desirable in.",truqtures

, " ;::,,~~' .., , '

where heat _~s produced during the day from manufiioturing,operations and arrangements ha!e to be made for the heat to espape";tp,tJlJ',,ol,l,tside.

Therefore, the ways ,i!l vhi ch aluminium should)Je us ed w~th"O.I!L¥i,tl;i.out

, 1 , ~

other materials ;requires study acc9;rding to. the con4i~ionfilc'iiff~9~Ang,

,.-" '::'-.]' -,' , ' , --., ^,

each building.

58. The quantities of aluminium econo~ically justifi~ble for use in

~;;~ ~r;

government and connercf.aL buildings in Africa can qn1yJ)~;.d,,~ermined

in'~h~'~hort-term'asPlan~.beco~~.knOWnf;:t'

gcve;rnmental:l',""<l. private, projects. For tllis

. r~:r:orh inqtq~'ies wer~ m~de

^""," " , .-- ^,~, ^of

some~~~iciin~

^.

governments as to their plans for public buildings andmateriiil

require-mentsan~'ai~~ihd~'a

ttitude t"r:Cl'ds alumini;

~iJ;lfP~hli; ~;uSing.

^The

re~ults

^rehe';t'

c~~~lictil)g Y:i.ew;:p~ints

^and

~'~~~riences;

^{a lim:kted}

acee;t~'ce

-: ;!,,;" ^";1:, of'aluminiun' ..-, ".

fo.rwi~dows

' , : , , : : :; :,: b'ut also . continued use of.-;:.' j ' , ,." ' .'

s~eel

-,

painted windows; some_{. ,~}, " .. ," ' . . dissatisfaction~>li~hi -', i " __ c , " certain previcys" " •'.' '.' expe~~ences','

with aluminium roofing:tljat .indicated i9,Proper install,atiqnsaI]d

. - - ' : ' . " • ul ~-.'."oJ " "

improper uses typica~ M early ,exPJriences 11).. oH,er .co~1';qi,eii';.,ins'l!i'i,,cient familiarity with the ~etal and technical methods of installation; and

in'sli'f'fJ:'cie~ts'a'1es pr~mb't:f\:ih

by alumini;,m 'cqmpanies or

age~ts;

^high

.,':' " ' " 1 . " . ' " ,.c,L.L, , .',:J; ',,' !:: J

priess Tor aluminium products associated wi th the small usage; and in certain coUiih·ies'a common acceptance of asbes'tos-o'ement

ro~i'i~g

made in those :countrieS.

59 •.

Nevertbefess, i

t _w~uld'

se"em .that in public housing and indivi,d,.ual private

housihgincl~di~

^rUral

d>le'll~ngs,

aluminium is bound to

oontinue to make inroads Ln Africa en galvam.z.ed iron. roofing and

" ' , ' , , ,

.

Ft.cN .14/ AS/III21

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58

"'1.

asbestos-cement roofing. The galvanized deteriorates'~nd^becomes

un-sightly as well as unusable-after some years' of' exposure to rain

~~

oxids,tion inmost oountz-d e e , -"Only repeated painting can lengthen the"life of the -galvanized~roof. Th" asbestos-cement'roofing material is ,heavy, and suffers oonsiderable Loao from breakage -in transport - ' andino-installatiOn. ,lin' unattractive fungus cover-s i t at -times.-Aluminium does not ha-ve these disadvantages~ 'For-true economy where

as, i,J), m~,cases a dwelling, even if made of mud and grass', can be

maintaine&ifo~,4.0 yeal's-or more and kept attractive

,lith

plaster

and paint" _al~iumwould justify encour-agemerrt in'-hOUsingproirammes by governments. This ,Iould be particularly 'approp:Hate

as

part of

ca.rnpa.i-grtac£~;r:1i:<iIt,terhoustng in order to improve' sanftation -and

to

reduce disease.

60.

The grass and thatch rodf dver'aclay-m~dwall1s -oommon in .-, tropiical Af'rieb.,,' This ccmbination shelters disease carrying insects Lnc.Ludf.ng ticks,_'f'Laas and 'l:Cce) that spread typhus (noketts:ta) and relapsing fever, and'mites that also spread 'typhus. These di·~e':3.ses' a.l;e preva;lent in EastA1ld..6a, Uganda, Ethiopia, Mozambique

,zitmi:H.i/'

anjl I!J;lS_t ,Mrica.

11

The clay mud wali, if sufficiently thick, has 'the

advantage_'Of,. cool -interior during the hot days , - I f ' sprayed with insecti,cides,·and Lf,tho crBiG-ksaro sealed, the wall can become' relatively aaniiary. __ , The grass or thatch rocf cannot

be

given the same _eff~ctive treatment. Also, it is a constant' fire menace, and ,reCiJ.ires pe:t.'iodic repair or re:placement.

j ,.: .

t~opicalAfrioats" -. c. I

One,of

J .'.

whenever 'people can afford it.

The metal roof has consequently been adopted in 61.

rural'and'iu'ban dwellims

the ffrst"S'i~~s th~y iiike when they acquire sufficient cash is, -\;0

.' - c,

ins~all-a metal roof, not only to save on maintenance but _a~so as a matter of prestige over their neighbours. Galvanized iron has been commonfy 'usedi,- pl'aced abo,fe" 'the' mud-clay 'walls. But except -in oertain

11

^{George H.T.'} Kitlible, Tropical

Africa,

The Twentieth

Gen'turyFund,

New York,

1960,

Vol.

II,

pp. 48-49.

E/~1.14/AS/II/2/j Page 59

locations in Africa, as in the high elevations of Ethiopia, galvanized

deterior~tes rapidly unless repainted periodically. Also, as already noted, it transmits heat into the dwelling unless insulated from the interior by another material. Aluminium, on the other hand, reflects most of the heat when new, does not re~uire another insulating material, and still retains an advantage over galvanized after both become dull.'

Conse~uently, the shine of the aluminium roof is seen commonly as one flies by airplane over parts of West Africa, and it is increasingly appearing in remote sections of East Africa.

62. Some countries have made better roofs a matter of government policy. In Venezuela, the government in 1958 was contributing part of the costs of aluminium roofs to farmers who would remove the thatch roof with its hazard of disease carriers. In Ghana, a

sche~~

was adopted in 1955 to make loans to rural Villagers through village housing societies for the improvement of roofs. About 5,500 loans were made in five years, averaging ~109 each (US~306). The various materials used for roofing in this scheme were not reported.

lI

,93.

Charla has made the general encouragement of the use of aluminium instead of galvanized iron a government policy. In the Volta River resettlement housing scheme to care for persons displaced by the reservoir of the Volta project, the government adopted aluminium roofing and siding. The Ghana Housing Corporation builds a rental dwelling for lower incume groups using aluminium sheets on the roof of a two-storey building with six dwellings; built of

concrete.~

The government does not Grant import licenses currently for galvanized sheet. To stimulate the growth of aluminium consumption in Ghana and

Roof Loans Scheme for Rural Housing, memorandum report of B.A.N.

Travallion, Chief Town Planning Officer, Accra, Ghana, to the

Bureau of Social Affairs, United Nations, New York, 3 November 1960.

Economic Commission for Africa, Pilot Enquiry into Housebuilding Costs (HOU/WP/5/ 31 July 1964) p.6.

E/

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looking towards the future supply of ingot from the Volta power-aluminium projeot, the government granted special concessions in 1959 to Aluminium Limi ted (Canada) to establish an aluminium building sheet plant in ",hioh the government also obtai~ed a 40 per cent participation in the equity capital. The company promoted the sale of corrugated aluminium and other sheet products by means of direct selling methods to reach illiterate sections of the population. A oolour cartoon film was shown in regular cinemas and sent by mobile trucks into villages.

Also, sales vans, roofed and deoorated with aluminium sheets, went around the countryside, manned by Ghanian salesmen, giving sales tal~

through a loud-speaker system to the oongregatinu' crowds around the

L

trucks.

Y ; ,

64. The greatest difficulty facing the adoption of corrugated and other aluminium roofing in Africa is its initial higher cash cost over galvanized iron in most countries. An additional factor may be the growing capacity ~o produce galvanized in Afrioa. Typical retail or wholesale j1ribt:s in 1965 for getl""'nized iron_and alum;p; urn

Y

J'.A.Person, The Promotion of Aluminium Fabricating in ,rest Africa Conference On Africa of the School of Advanced International Studies, Johns Hopkins University, Washington, D.C. October 1960.

EI CN .14/AS! III21

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an competing gauges in East Africa"were as f0110>ls, adJustea. to US$ (Table II1-6) (field trip):

. Price

;','

TABLE III-6

of corrugated galvanized iron and aluminium in East0 A f r i c a

1965 (most common1gauges in each country)

Location

Size

& gauge

Price basis'

Corrugated Corrugated galvanized, aluminium

iron

. US$

Salisbury, Rhodesia ; ••

Dar-es-S'alaam,: Tanzania

Per piece

.rEr!;ail.~ $1.32

s

1.32 ,lholes8,l

a.

_1~12 1.12

.Retail 0.234 0.35

Retail 0.234 0.35

Wholesale

17 .2iE1

^{16. 94}

^lY'

. i

"

-.

" """ "

Mombasa., Ken·ya

Addis Ababa, Ethiopia • 1 by 2 uet.:::-es 39 & 37 gauge

24 ga.2! sq.ft.

24 ga.2! sq.ft.

23-24 S.W .0.

100 ag.ft.

Wholes.ale price, subject to negotiation. Ordinarily, there is no dif-ference between wholesale and retail price. .

Cost per 100 square feet including roof fasteners.

It will be noted that in Addis Ababa' the prices of galvanized and

aliunini~'corrugated

sheets of the same gauge and size are

ide~fica1.

In Kenya

a~d

Tanzania, aluminium is about

50

per cent more expensive

than;;'~he

galvanized for

e~uai

gauge and coverage.

:t~

^Salisbury,

•. . : -j,'c;.;,i ,~\,. " ' , .' ._ "'.

_"-Rhodesia, aluminium is slightly less costly than galvanized, including

the'g~~t

;'troof fasteners, when priced per

lob Squ~e'feet at~hole­

sale. In Salisbury and also in Lusaka, Zambia,' where corrugated asbestos-cement roofing is manufactured locally, the price is as mu.c.lLas.__

one-:~~:!,,lt!p._J_~J>E!_.tQ,M eit4§t:.;:ga),Y:~i:4edor a-lumiriiuIn roofing

wr

100sqiJ.a,re '. feet.

_ _ _ _ _ _ _ .l._""_

E/CN .14/AS/II/2/

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65.

In some other countries, corrugated aluminium is also priced

. ... ' "","

-at retail about the same as galvanized for equal _gauge~,and area coverage. In Ghana, a square metre of corrugated aluminium roofing on a government housing achemeocatsUS

,,;5.

10 as compared wi th a price range for a square metre of galvanized iron between

.UQ$5.40

and

$8.

jo on

go~ernm:enthou~.ing'

programmes in other

Airi~~~ountries.

No explanation was given fo;this

advanta~e

^of

alumi~ium.lI

^The

^ECA

'staff On housing; repoi·ts"that in the Cameroun' whereco'rrtigated aluminitimisproducedfrom imported sheet, the prioe is about the same as for galvanized iron. In the USA in 1964, a typical

whoJ.esa,le ,price for corrttgated aluminiullf w'as 40¢per poimdas'colnpared with galvanized at 7.2iZ I,e!,' pound for 26ga,.ge. At retail, the price was 44-iiZ per pound 6faluminium and 16iZ per pound of galvanized.

But for equal thickness, one-third of a pound of aluminium gave the

I• .' ' . " " , ; ; ." .," ,1

same covel'age as one-pound of galvanized, and the reta:jjl Price was

..

, almos t the s'ame for each based on coverage. In one case,

100 ..

square feet of aluminium weighing, '27, pou~ds ^{sol'd for $12.00} wbe",.e,":"

'100 square 'feet 'of'galvanized w~~gl1ing'8). .pounds sold. for $1,3.00.

" - , ~ , , " " .... --,

For such oompetition xo be truly equal in prioe, the aluminium must be used in sucn away thatcits lesser strength does not require other costs of adjustment. If an aluminium roof is to be

walk~d On frequently, as has been reported' in some African areas, ,tnen ;i.twill not . be .able towi thstand denting as would an equa.L

gauge of ga.lvanized iron. In,such,a case, aluminium'inay not b!!

appropriate unless the ecenomr-es can be~,gainedto oOrllpet~

with

galvanized by using longer .• lengths of aluminium

of

thicker gaUge, as offered by one company' in Rhodesia.

Economic Commissi6h for Africa,Pilot Enquir:r into Housebuilding Costs. (HOU/WP/5) 31, JUly 1964:, :p.29. The 111'1.Ce of $5.10 perta.'ins to aluminium roofing although erroneously shown as oorrugatediron roofing.

F/ CN .14/ Asln/zl

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66. These illustrations of equal price indicate possibilities where both metals are produced at low cost and where competition is intense, as irL!'he FSA. In "ddi!:i,o':.t:_'!l1ere transportation ccst s rise with weight, aluminium will have the lower cost for the same thickness as

the galvani~_eci,,?,!i':.1i.(Jne:,tl:l:i,I'dthe weight. But finally, whera servioe life is oompared,galvanized unLeos repainted regularly may not La.st

"vel'

·12

years,Cin cornmon-vus.e, ·-aeooI'di·ng to US exper i.enoe , WhGrBil.S the aluminium may last 40 years ^"I' long€r,.Aluminium is the'least 8cxpensive material under such conditions. \lhile this point may not appeal to-c,c

the pMI' pers~n" who 1-fah't's''t'o' 'pay' 'the Leaa't cae h today, i t is important to governmen~iS:_.investil16,;i.npub.Lt,c h9using. programmes and to commeroial buildings where the test may be to get the least cost over servic€ .'

lifiO!-;

\ '~'., ;

67.

:In>,J>a.j3t Africa, h,o:wever., an addi ti.Ql)a). consideration for gove:r:n-ment policyi~Qatthe'l'e' 'is' Tar more galvanized c=ru/sa'ting caparity in existAllce and planned tod.ay than cJrrugated aluminct.um capaoitY',:cThis oapacity, shown in the following Table 111-7, is based on imported flat iron .sh e ef and import,\d zi]1'lp ..at ..coast a.l po

st

a , So far as foreign

\'"

axchanj e is ihVolved, for a~ e.c>ual gauge of galvanized and aluminium, disregardi~,,..di.fferences~ll ,w,eight, :1<1'\8.r'",,\oul,d. 00 ,li,t,tle difference between importins and corrugating either flat aluminium or irrn sheet.

, - Zi'nc-need

-",,'f'bs litportea-for-gaIVanizi'ig--§.s--H 1s 'produced 'in Zambi

a

but is in faot imported' from ~iseWhere. There is also little dif-ferEiniJ'-e-asofl,if64in---rIDj:Jorting aluminium ingot

intoDar-es~alaan

for casting, rolling and oorrugating, or importing into Dar-es-Salaam flat iron sheet for galvanizing and ,corrugating. The o.i.f. price of the aluminium ingot was $540 per metric ton, and adjusted on a volume basis )f

1/3

was equal at ~l80 to the volume 'of a metric ton of flat iron sheet at a c.i.f. price of $186, approximately. No adjustment is made here for melting and scrap losses in converting aluminium to sheet, nor for scrap losses of the galvanized iron.

---_ ^...__

^...

E/CN.14/AS/II/2/j Page

64

TAJ3LE 111-7

East African Plants for Galvanizing and Corrugating Iron ,and corrpgating Aluminium,

1965

EAST AFRICA. Estimated capacity

_ _ _ _ _ _ _ _ _-o-:- ~m~e;..:t:::r;.;i;.;c:_~.S'!1sjyea.r

6,000E!

Galvanizing and corrugating ~lants' Existing._'

Steel Africa Ltd., Mombasa, Kenya ••••••••••••

Uganda :B.,g,tti, .Kampala, Ug and.a- ~- . . Mabati _~td., Dar-es-Salaam, T!1-llzan~'1-"""'"

~nned, '"

Steel Company of Ethiopia, Asmara , Ethiopia ••

Chandaria family, Lusaka, Zambia ' ..

Sabean

UHli

ty Sh~re,

GO.,

Akaki, Ethiopia •••

tTgandas'tee'l Ltd.; ~ilbale, Uganda ..

Aluminium oorrugatin~.plants, Existing,

aluminium Af~ioa.Coo Ltd., Dar-es-Salaam, Tanzani:>

Aloan Aluminium of Rhodesia, Ltd, Salisbury;

Rhodesia " ..

16,000 5,006 25,000

48,O~0

12,000 12,000 24,000

N.A.

48,000

N.A.

6,000

(l966)!1 (1966) (1965)

Sources, Ethiopian Aluminium Company, Addis Ababa; and

W.S. Atkins & Partners, Development of the Steel Industry in

East and Gen.tral Africa, Economio Commission for Africa, July

1965

pp,

46-47.

'!:I

Will cOl'rugate a~umil1ium, also"

BV

Mixed products.

E/ CN

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68. This rough equality from a foreign exchange pcint cf view between ccrrugated aluminium and ccrrugated galvanized iron wculd change in favour of aluminium during its service life if two or three times as much more galvanized would have to be importedfcr replacements. If the galvanized lIere protected by periodic painting,i;his extra cost would also have to be considered in the comparison.

sheet were to be made in East hfrica by 1980, as lS

If the flat iron POSsible,.!! the cost comparison f~om a foreign exchange point cf view wculd have to be adjusted again.

69. T4e consumption of galvanized ircn sheet in much of East Africa was approximately 45,000 short tons .i.n 1959, as measured by imports of flat and corrugated sheet. Incomplete data for 1962 indicate a sharp drop in imports (Table III~8).

TABLE III-8

Ga1vanized and, Flat Iron Sheet, Imports, East Africa (Short tons)

corrugd.te-cl ~_,•. " .. ,.. . Tanz ani a-flat- ^{<I ..} " " " " ' . ' "~^'0..

Malawi, -Rhodesia and Zambia-flat ••••••

corrugated ., ..

1959 1962

2, 289 13,487 19,124 3,859

159 97

5,300 2,343

292 175

4,592 2,440

3,856 N.A.

9,511 N.A.

45,123 N.b..

...

Total

• • o - • • ~ .

, ,

...

^{"' '}

..

. . . .G ..

COUNTRY' Kenya-flat corrugated Uganda-flat corrugated

Source: Alcan International Limited and Alcan Africa Limited •

.!! W.S. Atl<:in.s& Partne:,:,s) Development cf the Steel Industry in East and Central Africa, Economio Commission fer Africa, July 1965.

' . , :-~i.

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70. It .would appear from this review of the place of aluminium in building construction that the subject deserves the attention of the African' government agencies concerned with publio"works, ~ublic

housing, and health. '~he development of unifcrm and co-operative policies in these matterswher8 Justified would accelerate the demand for aluminium and have ^.the more important benefits of carrying out vital public purposes.

Aluminium and African transportation

71.

Africa" governments should also have a special interest in encouraging the use cf aluminium in buses and trucks on public high-ways, and railroad ca~R on :"ubli a railroad systems. 'The metal has

. i . ' .

made much progress in such uses in Europe and the United States for

commercial reasons. It reduces the weight of the vehicl~s, and increases the revenue per voilicle by increasing the weight of cargc or number

of persons ",hD" ca""he. carried, . 'By 196J.~_.t~h.~. US consumptio.nof··alUlDinium in transport"tioYl. ···automobiles,. truck§,J;'§,ilroa<ls, ..airplape$ ,.$hips and boats- was almost as great as in building construc]ion, the leading field.

72. Aluminium also reduoes the costs of maintenance and repair

required for steel and woed in transportation vehioles. Likewise ;_.

it reduces both the over..,all weight of the vehicle and ·the amount of wear a·nel t e ar por unit of comrnezood.e-L ·traffic (cargo or- passengers) , both of t'", '."0 . .'~G~ r·ll.', 01' t!le J.'Bi·.J.,roM bed ·or the highway. Ii>

reduces the cost of fuol consumed 'per unit of 'commercial -traffic, and permits greater speeds,

73.

Eccnoma.e s of this type are veryimportallt to"developing oountries, and espeoially in Africa, ",h8,1'e rellair and. maintenapce of r-oads-and railroads can

DO

costly due to rainfall and humidity. Vehicles do not last long ",i thout oonstant repE-ir, and roads deteriorate rapid,1y-.

from clima.~i(: vq;;'lQ,.jjriQ~~:"':'g,:lJ.,_,ffie_...po und.i ng cf'. heavy vehicles._. In_., Thailand; buses and' trucks are changing from the use of wood to aluminium to reduc8 costs of repairs and to increase pay-loads.

'--'~

,IV ^CN

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In India, the government's railroad system ;is using aluminium in""ars.

In India, the government's railroad system ;is using aluminium in""ars.

Dans le document Africa and the aluminum industry (Page 63-75)