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THIS PAGE EXPLAINS IN PLAIN ENGLISH WHY ROOFKRETE IS A PERMANENT MATERIAL
RoofKrete Freeze / Thaw Resistance
If a membrane is described as waterproof it means that no water molecules will
pass through it and therefore if no water molecules will pass through it, it means
that no water molecules can be present within the membrane. The normal
laboratory test for this is to freeze/ thaw cycle a sample of the membrane.
This consists of first weighing the sample then immersing it in warm water
at plus 20 degrees celsius for 8 hours and then freezing it for 16 hours at minus
30 degrees celsius. This cycle is repeated 10 times over a period of 10 days
then the sample is weighed and if it is found to be of identical weight to the sample
before freeze/thaw cycling then it is waterproof. After freeze/thaw cycling RoofKrete
was found to be of identical weight. click here for RoofKrete Freeze/Thaw test report
Some other examples of waterproof materials used for roofing are:
Glass, Lead, Copper, Galvanized Sheet Steel.
Some examples of materials which are not waterproof but are weatherproof are:
Bitumen, Polymers, Polythene Products and in general all membranes manufactured
from petrochemical products.
RoofKrete Carbonation Penetration
Carbonation is the penetration of carbon dioxide from the atmosphere into the interior
of concrete. This causes the reinforcing metal to rust and fail even in good quality
concrete structures as the pore water in the concrete is converted to carbonic acid.
This rust builds up pressure which forces off the covering layer of about 20 mm exposing
the reinforcing bar. Urgent and expensive remedial treatment is then required.
The normal laboratory test for depth of carbonation is by a Phenolphthalein indicator.
When RoofKrete was tested using an 11 year old sample the depth recorded was less
than 0.1mm. The testing laboratory at Portsmouth University concluded that the
material would carbonate to a depth of 0.2mm in 50 years! The cover on RoofKrete
System 4 is about 1.5 mm this gives a carbonation penetration rate of about 750 years
before it reaches the metal reinforcing! But even if carbon dioxide penetrated to the
metal there is no pore water present in RoofKrete System 4 to cause rust! (see above)
click here for RoofKrete Carbonation test report
RoofKrete Dimensional Changes
Materials used to cover buildings expand or grow bigger when the temperature rises
and contract or become smaller when the temperature drops. This thermal movement
cycle happens every 24 hours winter and summer. Roof membranes can fail because
of Differential Movement.This happens when two materials are fastened together
and each have a different rate of expansion and contraction. The result is that the
weaker one will become fatigued and fail usually by cracking at various stress points.
RoofKrete solves this problem in three ways:
1. RoofKrete system 4 has a much lower thermal movement than membranes
manufactured from petrochemical products.
2. RoofKrete System 4 forms a monolithic structural system on a roof which is able
to withstand laterally imposed loads far greater than that which is normally
applied to wooden decks - it is stronger than wooden decking.
3. RoofKrete System 4 is installed as a floating system and therefore differential
movement is not an issue.
click here for RoofKrete Dimensional Changes test report
RoofKrete Heat Resistance
RoofKrete System 4 is the only waterproof membrane in the world which does not
contain any combustible material. It remained integrated when heated for four hours
in a 1000 degrees celsius furnace! That would mean that it glowed red hot for four
hours and still remained in one piece!
click here for RoofKrete Heat Reststance test report
RoofKrete Load / Deflection Characteristics
RoofKrete System 4 can deflect as much as 4 mm over a length of about 500 mm
without cracking. This is far in excess of that needed to accommodate any building
movement or foot traffic on a roof.
click here for RoofKrete Load / Deflection test report
RoofKrete Solar Radiation Resistance
RoofKrete System 4 is a mineral product and therefore is not affected in any way by
the various types of solar radiation.
Click here for more RoofKrete test reports
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