Ask a Tradesman
Flat roof re-felting
We have a small roof on top of a ground floor bay window that needs re-felting, can anyone advise please?
by all means use epdm rubber as it is the best material on the market if laid correctly, but please do not put it over the top of a felt roof unless you want future problems, this is total lazyness and a cowboy job
do not use epdm as it is a pitched roof you are enquiring about it should be a breathable membrane, up grade your thermal insulation at the same time, I am assuming it is a small bay and as it is less than 20% of your total roof area will most probably not require building regs. but as every council is differant you would need to enquire with your local building regs officer.you will have to remove the existing felt.
Answered 1st Dec 2012
I would recommend using Firestone Rubber as it can be laid over the existing felt if it is in reasonable condition and this material carries a long guarrantee.
[ Norjan Properties Ltd ]
Note: The answer from ADR is misleading as Firestone EPDM can be fully adhered , mechanically fixed or ballasted. Therefore leaving the existing roof surface in place is neither lazy or a cowboy job and provided the surface is good as I said is a sensible precaution this time of year.
Note : The answer I gave was based upon the information given in the question . I did not make any assumptions on what ' might be ' happening as ADR & Fibretech seem to be doing. I always feel it is better to give your opinion on known facts rather than conjecture it avoids the lengthy confusion that appears to be growing around a very simple problem with a very simple solution.
Answered 28th Nov 2012
Na - i would say that ADR are correct if the roof is being replaced it is generally due to is leaking. If you have wet boards and felt then these will sweat and coarse mould. Of course you should also be insulating bays to prevent interstitial condensation since these are generally unventilated flat roofs.
Answered 7th Dec 2012