Flat roof repair

[Anonymous]

I have a flat roof, single story extension, which had it's last felting done 11 years ago and now requires redoing. I have been told about using "green felt", whatever that is and also fibreglass method. The area is approx. 36 square yards.

Can you please advise me on the best method and if possible explain the pro and con reasons.

Will be most grateful for your help.

Many thanks

 

[Anonymous]

I would not advise fibreglass for a roof of that area. The expansion and contraction will be considerable and will cause problems with excessive movement at the abutments and edges.

A three layer felt system is the most reasonable all round method. It's fairly easy to install, does not need specialist repair if you get a problem with it and is in the midde cost wise. You can choose a system that will last anywhere between 5 and 30 years. (More years, more cost) The finished surface can be one of a number of options including green mineral, chippings, solar reflective paint or foil. personally I would recommend green mineral (or you can get red mineral if you prefer)

There are other single ply systems - a common one is Trocal. I wouldn't recommend this type in your situation. It is really a specialist application and needs specialist installation and repair.

 

[Anonymous]

We are in a similar situation - ours will need renewing in the next 5 years. a friend has said he has heard of a thick rubbery material that is now available with an expected lifespan of 50 years, but we don't know any more details - does anyone else?

 

[Anonymous]

Yes, I saw something about this - its called 'rubbershield' they claim to provide it in widths of 15m so can do lots of roofs as a single sheet with no joins

I have seen +ve reviews by roofers on diynot or somewhere.

Mark


rubbershield

 

[Anonymous]

Thanks very much to Johneds for his excellent and very helpful reply.

 

[Anonymous]

I did a green roof for my parent garage with a epdm pond liner (with a stated life of 25 years plus)

being a green roof (just a root barrier, drainage layer and seedums) it is further protected from UV which is the big enemy of these kinds of roof.

Another option to consider is copper. It's pretty specialist and I imagine expensive but it shouldnt ever need doing again.

G.