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IS0
I NTERN AT1 ON A L O RG A N I ZATl ON FO R STAN DA RD IZAT I O N
IS0 RECOMMENDATION
R 393
ASBESTOS-CEMENT CORRUGATED SHEETS
FOR ROOFING AND CLADDING
1st E DIT I O N
November 1964
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRlEF HISTORY
The IS0 Recommendation R 393, Asbestos-cement corrugated sheets for roofing and
cladding, was drawn up by Technical Committee ISO/TC 77, Products in ushestos-cement.
the Secretariat of which is held by the Association Suisse de Normalisation (SNV).
Work on this question hy the Technical Committee began in 1956 and led, in 1963,
to the adoption of a Draft IS0 Recommendation.
In December 1963, this Draft IS0 Recommendation (No. 691) was circulated to all
the IS0 Member Bodies for enquiry, It was approved, subject to a few modifications of
an editorial nature, by the following Member Bodies:
Australia Ireland Republic of South Africa
Austria
Israel Romania
Belgium
Italy Spain
Colombia Lebanon Sweden
Czechoslovakia Morocco Switzerland
Denmark Netherlands Turkey
Finland
New Zealand U.A.R.
France Norway United Kingdom
Germany Poland U. s. s. I<.
Greece Portugal Venezuela
Hungary Republic of Korea Yugoslavia.
Four Member Bodies opposed the approval of the Draft:
Brazil, Japan, Mexico, Peru.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0
Council, which decided, in November 1964, to accept it as an IS0 RECOMMEND-
ATION.
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ISO/R 393 . 1964 (E)
CONTENTS
Pages
.................................
I . Scope 4
...........................
2 . Corrugated sheets 4
2.1 Composition . 4
2.2 Classification . 4
2.2.1 Geometrical classification . 4
2.2.2 Mechanical classification . 5
2.2.3 Choice of the classifications . 5
2.3 General appearance and finish . 5
...........................
7.4 Characteristics 6
2.4.1 Geometrical characteristics . 6
2.4.1.1 Profiles and sizes . 6
2.4.1.2 Length, width and coverage . 6
.........................
2.4.1.3 Thicknesses 6
2.4.1.4 Tolerances on the nominal dimensions . 6
2.4.2 Mechanical characteristics . 6
2.4.3 Physical characteristics . 6
.
2.4.3.1 Impermeability . . .
6
2.4.3.2 Frost cracking . .
6
...............................
2.5 Tests 7
2.5.1 Measurement of the thicknesses . 7
2.5.1.1 Checking of the minimum thickness . 7
2.5.1.2 Measurement of the thicknesses in the broken sections . 7
2.5.2 Bending tests . 7
2.5.2.1 Unit bending stress .
8
2.5.2.2 Classifying index . 8
2.5.3 Impermeability test . 9
2.5.4 Frost cracking test . 9
.............................
2.6 Marking 9
................................
3 . Fittings 9
............................
3.1 Composition 9
3.2 General appearance and finish . 9
...........................
3.3 Characteristics 9
3.3.1 Geometrical characteristics . 9
...........................
3.3.1.1 Shapes 9
3.3.1.2 Length, width and coverage . 10
..........................
3.3.1.3 Thickness 10
3.3.1.4 Tolerances on the nominal dimensions . 10
3.3.2 Physical characteristics . 10
3.3.2.1 Impermeability . 10
........................
3.3.2.2 Frost cracking 10
.............................
3.4 Marking 10
...................
4 . Sampling, inspection and acceptance
10
4.1 Inspection of each item of the consignment . 10
4.2 Inspection by sampling . 11
..........................
Appendix A - Testing 13
Appendix B - Extracts of IS0 Recommendation R 390 " Sampling and Inspection
of Asbestos-Cement Products . 14
.. 3 ..
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E!!!
ISO/R 393 - 1964 (e)
IS0 Recommendation R 393 November 1964
ASBESTOS-CEMENT CORRUGATED SHEETS
FOR ROOFING AND CLADDING1
1. SCOPE
I
This Recommendation applies to straight or curved asbestos-cement corrugated sheets and
fittings without any metallic reinforcing media, to be used for roofing and cladding.
It defines certain conditions of manufacture, dimensions and acceptance tests for these
products.
2. CORRUGATED SHEETS
2.1 Composition
The sheets are made from a close and homogeneous mixture essentially consisting
of a suitable inorganic hydraulic binder, asbestos fibre and water, excluding any
materials liable to cause ultimate deterioration in the quality of the sheets.
The sheets may be left in their natural colour or colouring matter may be added
in the composition; they may also receive adherent coloured or uncoloured coatings
on their surfaces.
2.2 Classification
The sheets are classified both according to the height of their corrugations and accord-
ing to their load bearing capacity.
2.2.1 Geometrical classiJication
(Classification according to the height of the corrugations)
I
DEFINITION - The height h of the corrugations is the height measured from the
valley of the corrugation up to the crown of the next corrugation (see Figure I).
This dimension includes one thickness only.
Fig. 1
1 Asymmetrical section corrugated sheets are covered by-ISO Recommendation R 394.
z This Recommendation also applies to autoclaved sheets when the binder is partially replaced by ground silica.
I --
_. 4 -
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ISO/R 393 - 1964 (E)
DESIGNATION Of- THE CATEGORY
(1 ) deep corrugations
height not less than 42 min
(2) medium corrugations
height less than 42 mm
and not less than 30 mm
(3) shallow corrugations
height less than 30 mm
and not less than 15 mm.
2.2.2 Mechanical classification
(Classification according to the load bearing capacity)
DEFINITION - The sheets are classified according to a classifying index C,, which
takes into account the minimum unit bending stress value of 160 kgf/cm2, that
defines the intrinsic quality of the asbestos-cement material (2.4.2), and the nominal
bending section modulus W, corresponding to the theoretical profile (2.4.1.1) and
to the nominal thickness (2.4.1.3) of the sheet.
The classifying index C,,, represents a minimum acceptable load bearing capacity
related to a width of one metre.
DESIGNATION OF THE CLASS
(I) class 150 C,,,: 150 kgf/m
(2) class 212 C,,,: 212 kgf/m
(3) class 300 C,,,: 300 kgf/m
(4) class 425 C,,: 425 kgf/m.
One lower class may be introduced into this classification; it has to be chosen from
the same series of preferred numbers as the classes above.
2.2.3 Choice of the classifications
The national standards may prescribe one or other or both the above classifications
on the condition that the minimum unit bending stress value of 160 kgf/cm2
provided for in 2.4.2 is maintained.
(a) In order to facilitate the interchangeability of the sheets and consequently to
ensure the tightness of the roofs when matching sheets, a sheet should keep
within the category of its geometrical profile irrespective of its minimum load
bearing capacity.
(6) It is not permissible to change the class according to the minimum acceptable
load bearing capacity of a sheet as determined by 2.2.2, even if the verification
of bearing capacities carried out according to 2.5.2.2 indicates an index cor-
responding to a higher class than the classifying index C,, for the sheet.
2.3 General appearance and finish
The sheets are elements the cross-section of which consists of approximately sinus-
oidal corrugations to make the sheet rigid. The surface intended to be exposed
to the weather should be finished smooth.
The edges of the sheets should be square, straight and clean.
-5-
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6
ISO/R 393 - 1964 (E)
2.4 Characteristics
2.4.1 Geometrical characteristics
2.4.1.1 PROFILES AND SIZES
The profiles and sizes of the sheets should conform to those in the national
standards of the producing country or, failing this, should be as specified in
the manufacturers’ catalogues.
2.4.1.2 LENGTH, WIDTH AND COVERAGE
These nominal dimensions should conform to those in the natioiial standards
of the producin_s country or, failing this, should be as specified in the manu-
facturers’ catalogues.
2.4.1.3 THICKNESSES
The sheets are of two types
- A, sheets with a constant thickness
- - B, sheets with a profile of regularly varying thickness.
The nominal thickness of the sheets of type A and the extreme nominal thick-
nesses of the sheets of type B should conform to those in the national standards
of the producing country or, failing this, should be as specified in the manufac-
turers’ catalogues.
The actual thickness measured according to 2.5.1.1 should at no point be less
than 5.5 mm for the sheets of type A and 5.2 mm for the sheets of type B.
For the sheets of the category “ shallow corrugations ” (2.2.1) the actual
thickness should be not less than 3.5 and 3.2 mm respectively.
2.4.1.4 TOLERANCES ON THE NOMINAL DIMENSIONS
(a) on the length
Upper deviation: -+ 5 mm
Lower deviation: - 10 mm.
(h) on the width
Upper deviation: + 10 mm
Lower deviation: - 5 mm.
(c) on the thickness
Upper deviation : free
Lower deviation: - 0.5 mm.
2.4.2 Mechanical characteristics
Tested as provided for in 2.5.2 (compulsory test), the sheets should give a minimum
unit bending stress of 160 kgf/cm2.
2.4.3 Physical characteristics
2.4.3.1 IMPERMEABILITY
Tested as provided for in 2.5.3 (optional test), traces of moisture may appear
on the lower surface of the sheets, but in no instance should there be any form-
ation of drops of water.
2.4.3.2 FROST CRACKING
Tested as provided for in 2.5.4 (optional test), the sheets should not show
signs of cracking or surface alteration.
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ISO/R 393 - 1964 (E)
2.5 Tests
The acceptance tests should be carried out at the manufacturer’s works on sheets and
test pieces cut off the sheets which the manufacturer guarantees to be sufficiently
matured.
(a) Compulsory tests
1. Measurement of the thicknesses (method as defined in 2.5.1).
2. Bending test (method as defined in 2.5.2, number of tests as indicated in the
extract of the table in Appendix B).
(b) Optional tests at purchaser’s request
3. Impermeability test (method as defined in 2.5.3, number of tests as indicated
in the extract of the table in Appendix B).
4. Frost cracking test (method as defined in 2.5.4, number of tests as indicated
in the extract of the table in Appendix B).
2.5.1 Measurement of the thicknesses
The methods of assessing these measurements and the instruments used should be
in accordance with the national standards of the producing country.
2.5.1.1 CHECKING OF THE MINIMUM THICKNESS
The actual thickness measured at any point should be not less than the minimum
provided for in 2.4.1.3.
2.5.1.2 MEASUREMENT OF THE THICKNESSES IN THE BROKEN SECTIONS
The thickness is measured in the crown and valley of the corrugations. The
actual average thickness is the arithmetical average of the measurements so
obtained.
2.5.2 Bending test
This test serves
- to determine the unit bending stress of the tested sheet,
-- to verify the classifying index C, according to the classification by the load
bearing capacity.
The test is carried out on pieces cut off straight sheets with a minimum length of
1.22 m. The width of the test pieces corresponds to the total width of the sheet
reduced at the edges by cutting along the axes of the outer valleys. Before testing,
the test pieces should be immersed in water for 24 hours.
Fig. 2
The test piece should be placed on two transverse fixed rigid flat parallel supports
5 cm wide, leaving between them a clear span of 1.10 m. It should be loaded at
mid-span by means of a self-aligning rigid flat beam 23 cm wide, parallel to the
supports and loaded at mid-span.
The thickness is not measured in the side of the corrugation,
3 This measurement also applies to sheets of type B.
as it is in direct relation with the thicknessses measured in the crown and valley of the corrugations and may be
deduced therefrom either by calcuIations or graphs.
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ISO/R 393 - 1964 (E)
Strips of felt or soft fibre not more than 1 cm thick are interposed between the
test piece and the supports and under the beam by which the load is applied.
The speed of application of the load should be regulated so as to realize an in-
crease of the unit stress of about 4 kgf/cm2s up to breaking point.
2.5.2.1 UNIT RENDING STRESS
The unit bending stress expressed in kilogrammes-force per square centimetre
is given by the formula:
where
P1
M=-
4
W = bending section modulus in relation to the part of the test piece
exposed to tension and determined from the theoretical profile given
by the manufacturer and the actual average thicknesses measured
at the broken section of the test piece according to 2.5.1.2, expressed
in cubic centimetres
P = breaking load, expressed in kilogrammes-force
I = clear span between the supports, expressed in centimetres.
The unit bending stress R,, corresponding to the breaki
...