Type of roof for a small extension

[Faz786]

Hi all,
Need some advice. We are getting a small kitchen extension and I want to know if I should go ahead with EPDM roofing. My builder is suggesting not to and go with fiber glass . I am not sure if it is because he has never placed EPDM roofing before

 

[freddiemercurystwin]

Ask him why. Fibreglass is OK provided he knows what he's doing. EPDM is far more forgiving. There's a mahoosive thread on here somewhere with people complaining about their roofs expanding (and making cracking noises) in the heat, I recall it's generally to do with enough fixings of the board into the joists.

 

[freddiemercurystwin]

A

Thread 'Noise from GRP flat roof'

21 Aug 2013

About 3 years ago we had a cold deck flat roof built onto a new extension (approx 35m sq). The roof is constructed of OSB T&G board with a grey GRP coating.

From the outset we have had creaking and banging noises from the roof that coincide with rises/falls in temperature, the problem being mainly restricted to the warmer months of the year.

We have checked the plastic fascia and guttering and even had expansion joints retro-fitted but the problem persists. Windy weather is not a problem (unless it's hot).

Our builder and roofing installer are at a loss what to do next...

• ajs1954
• Replies: 112
• Forum: Roofing and Guttering

• 

 

[^woody^]

Lots of builder's offer fibreglass because they think it's easy - a few tins from the merchant and a roller.

Strictly, installers should be fully trained in the system they offer.

I would only specify liquid coatings for very large commercial roofs as there are some advantages for certain roofs and situations and long warranties from accredited installers.

There are no such advantages for new small extensions, but there are more risks

So left with traditional bitumen felt or a single- ply membrane such as EPDM, single-ply wins every time.