Ask a Tradesman
Strip off felt prior to epdm?
I have been given 2 estimates for a continuous new flat roof over our porch, garage and laundry.
The first roofer said he can dry out the existing boards from inside and cover the old felt with EPDM. If required he would use 12mm osb boarding.
The second said to replace the wet board with 18mm osb boarding, leaving board that's ok, strip off all the felt and use EPDM / Both builders use Firestone EPDM
I must admit that I'm not looking forward to clearing the garage of all our property and the first builder said I wouldn't have to.
Who is correct?
hi im a certified installer of the Firestone rubber cover, overboarding is fine considering the boards underneath are not soaked and rotten,
rotted boards should be completely removed and replaced with 18mm OSB leaving a 3mm expansion inbetween all boards, its ready for the rubber then,
11mm OSB is fine for overboarding onto a solid deck And if the felt isnt in to much of a state and is fairly flat then the drippers can be removed (felt around the edges of the roof and wall upstands if any) and u can then overboard being sure to find and hit the joists with your screws.. NEVER OVERBOARD SOAKED OR ROTTEN DECKS!
Answered 28th Mar 2017
The second one sounds better to me, garage shouldn't need emptying,that's depends on the roofer.
Answered 3rd Apr 2013
you may get a little bit of wet board fall down but only in pieces like weetabix so no need to empty garage. By the sounds of it the second builder will just cave in the old roof and let it fall into garage.
Answered 7th Apr 2013
I would go with the second roofer, If I come across a roof with wet rotten boards in the roof, there is no question it must be removed down to the joists, ok the garage may need clearing if there are important items in there then re-lay the roof with 18mm OSB ,only then can you lay the EPDM , but if it's your laundry/utility area, it will need venting using a stand up 193mm polypropylene vent.
All the best
Answered 8th Apr 2014