What is the best flat roof, or roof material for flat roof replacement? This is a question I have asked a whole lot, and to be honest there was never a right or wrong answer – But the advice I was given by Richard Davies of RD Roofing when I called his company out for the roofing of a new extension, there’s sometimes a kind of flat roof that will suit a flat roof of a particular size, shape, detail level or budget. So if you want some impartial guidance on the kind of roof I generally go for these days when remodeling properties free of sales patter, read on.
These have stormed onto the UK market after extended results in the USA and some other countries. The rubber or E.P.D.M. (Ethylene Propylene Diene Monomer) is normally made by Firestone, and can often be installed in one full layer without having to use joins (dependant upon size) which makes it an appealing prospect. It is very lightweight per square metre, extremely elastic and tough, so it lends itself to a lot of roofing situations. Nearly all new residential rubber roofs are glued down to a new wooden roof substrate, although they can in some situations be laid on top and mechanically fixed or weighed down with ballast. My personal preference for domestic roofs is a new install with new roof decking as a single ply membrane.
A well installed rubber roof, to the right roof, could last up to Half a century. Some firms will supply a guarantee for 50 years, but this guarantee varies from installer to installer. I question whether the company is still going to be trading in 50 years or if they’d honour the guarantee after a couple of decades have passed, so take this with a pinch of salt.
The Benefits of Rubber for the Roof
Price – Competitively priced, expect to pay 20-30% more than a torch on felt roof.
Suitability – Ideal for green roofs, light-weight, flexible and solid. Will not install well into roofing with tricky details, pipes, curved upstand walls, complicated gulleys or gutters because it will become full of joints, which can look ugly and lead to leaks. Good for nice simple shaped roofs, no naked flames needed.
Damage level of resistance – An incredibly durable roof, it can resist nearly all kinds of punishment besides heavy impact from pointed objects, but not being cut or vandalised.
Repairability – It is usually repaired very easily with rubber patches, similar to a cycle tyre, although they are not pretty to look at.
Appearance – For me personally, right here is the achilles heel. It’s a personal factor but a big sheet of black rubber, looks like a big sheet of black rubber if you ask me. Of course if it’s not noticeable from a window, should it matter?
Installation problems – Regrettably the evident ease of install has attracted shady roofers who fancy some fast cash. Look for a roofing company with good trading reviews or a history of fitting other kinds of flat roof. A large rubber roof will shrink over time, some say up to 10%, personally I’ve seen it at about 5%. Shrinkage may cause edge details and upstands to pull away from wall structure if they’re not fitted with the right fitting details, like a russ strip (mechanically fixed edge fixings). A better made fleece backed EPDM will resist or stop shrinkage, so if you have a large roof, this can be worthy of a look. A simple roof can be installed in rubber by a savy DIYer.
My personal choice these days when dealing with a new flat roof is rubber, for the reasons mentioned above, but there are lots of other options available which all have their own merits and qualities. In the Midlands I always use RD Roofing for my flat roofing projects, thye specialise in Rubber but take a look at their site if your in the area for more information on various other materials for flat roofs. For the DIYer you can buy the material direct from Permaroof UK Ltd.