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Leaking dormer flat roof

My rear dormer flat roof has been leaking for 12 months and I wasn't able to do anything about it due to illness. It is leaking badly now. The felt roof is over 20 years old and the roof is approx 12 sqm. I need the roof replaced and would like some urgent guidance please:
1.What questions do I need to ask the roofer before making a decision on who to hire and what type of roof replacement go for? What is best felt or EPDM? If felt how many layers would you recommend?
2. What should I expect to get from the roofer in terms of specs and price (I live in Warwickshire)?
3. Are the joists likely to be damaged and in need of replacement given the long exposure to water? If so how much would it cost to replace them all approximately?
4. At the moment the flat roof has no guttering (the water gushes down from the front of the dormer). Would you recommend I put some guttering or ask the roofer to provide a slight incline to the roof to allow the water to run into the main roof guttering as my neighbour suggested?
5. would you recommend that I have a Building Inspector from the local council to make sure that the job is done properly?

I do apologise for the long letter and lots of questions, but I have had problems with builders before and I am afraid that it may happen again unless I prepare myself well. Many thanks

2 Answers from MyBuilder Roofers

Best Answer

Epdm is the best product at the moment due to the fact there are no seams. Felt is just as good if done correctly. Always ask for 3 layers of felt 2 layers should be an sbs underlay and top layer a high performance mineral. The joist may be in a bad state if it has been exposed for that long but you can never tell until the roof comes off. guttering would be ideal so you can then chuck it off onto roof tiles to then flow into main guttering. Insulation would definitely be recommended as it makes a huge difference even if its rockwall put into rafters. I would hope to pay no more then £1500 for this work this would include scaffold but depends on average wage in your area.

Good Luck

Aaron M Baldry


Answered 6th Apr 2013

without removing the roof it is impossible to say what condition the supports are in,
epdm if the best material on the market at the moment for a roof that size it will be a single piece with no joints.
make sure they are removing some of the roof tiles around the dormer so it can be sealed under the roofing felt above and over the roofing felt on the sides.
the fact the water is running of the front of the roof means their are probably fairing stripes in place running the roof water in this direction guttering can probably be added to the front to run the water onto the roof tiles.
as far as building regs are concerned you would need to talk to your local council to see if they are required.
it would be prudent to upgrade your insulation in this part of the roof when it is being done.
scaffolding will be required .
as for cost it will depend on what your local labour rates are.
post the job on the site and get a local roofing expert to asses the damage and cost, pick one off the site that has proper feedback.
good luck


Answered 16th Jan 2013

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