Standard Colours.
Cement Grey. Other colours can
be made available dependant on quantity required.
Lengths.
Supplied in lengths required for individual applications up to 12m
(= over 39ft).
Over-Roofing can be laid as one sheet from ridge to eaves over
existing end laps, simplifying fixing and minimising laps on the new
over-roof (existing roof sheets have to be in line).
SLE Cladding Caution. When considering
using sheets in very long lengths, bear in mind the transport
problems as well as the handling problems associated with unloading,
storage and lifting on to and positioning on the roof as well as the
cost there of.
Weights.
The minimum sheet weight for the system is 2.44 kg/m2. Heavier and
reinforced sheets are manufactured to meet specific structural or
wind loading requirements.
Flashings/ridge.
Machine-made adjustable two-piece plain winged ridge flashings and
plain edged crown units are available. Hand made profile crown ridge
units and turned down eaves units can be made available.
Insulation.
Maximum 100mm quilt fibreglass mat can be used underneath the
system, using Profix 60 spacer.
Operating temperatures
The minimum and maximum temperatures for GRP sheeting are 20 deg.
C to +100 deg. C. Sheets will not become brittle or soften at low or
high temperatures.
Compatibility.
No chemical reaction with other established building products.
Means of escape.
Over-Roofing must not be used where the existing roofs form
part of or is located under a fire escape.
Labour Safety
Do NOT
walk on sheets, ALWAYS use crawling boards. Attention is
drawn to the Health and Safety Executive Guidance Notes HS (G) 33 "
Safety in Roofwork" published by HMSO in 1998.
Under this guidance note
asbestos-cement sheets are classified as fragile roof materials.
Although Over-Roofing will provide additional strength to the
old roof, for the purposes of maintenance , the roof should still be
regarded as fragile.
Transportation,
handling and storage.
Sheets are generally supplied loose. Store on clean level battens
at centres not exceeding 1.5m. Stacks should not exceed 1m and must
not overhang at ends. Secure
and protect from wind and mechanical damage. When stored in open
protect with opaque waterproof covers.
SLE Cladding Notes.
Ref. Obsolete
Profiles
There can be a
problem with really obsolete profiles, insomuch as the
manufacturers require orders totalling
a minimum quantity of 50 linear metres
before they will commence a production run of any one profile. This
quantity of orders may take a few days, weeks, months or even
years to assemble if it is a really old one or has been an unpopular
profile. Glass
Reinforced Plastic is expensive and fifty lin. metres is far too much
to purchase if only say 2 sheets are required.
The standard sheet
colour is cement grey and the surface of the sheet is very
smooth. Whilst all colours and surfaces degrade over time, it
will be some years before the sheet surface is capable of
retaining paint.
Remember these
sheets are intended for oversheeting only and not as
replacements. They are not reinforced like the DR Refurb sheets.
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