Flat roof repair or replace?

[Kuffs]

Hi all, I have a 6x3m garage roof that has started letting water in. I apologize if I don't use the correct terminology in the following expatiation. I should mention that I'm about to sell this house and obviously I want to avoid spending a fortune on fixing this problem. I have a friend who is a general builder and he has said that we should not bother removing the existing felt and just over-board it with shuttering ply and then torch on the new felt. Now, I'm a tradesman my self, but not a roofer. To me this doesn't seem like good practice, as I feel we would be trapping damp under the new timber sheeting? If I was keeping the house, I would rip off the old felt and make good the boarding underneath. If you take a look at the photos I have attached, you will see that the roof is failing mostly at the gutter end and along the cloak tops. I was thinking about using Acrypol+ to patch things up. Any advice would be much appreciated. Thank you!

 

[alan333]

If you want to do it on the cheap (and the boarding is sound) then just remove all the chippings and torch a layer over what's there.

 

[Kuffs]

Hi Alan333, Thanks for your response. I'm guessing my mate was thinking that by over boarding the existing felt,is would make a better bonding surface for the new felt. I do take your point though. Thanks very much.

 

[ree]

OP,
you would be practicing fraud on any new buyer's if you sold with that roof as it is but merely covered up.

The odds are that with that roof there is hidden damage - water damage & fungal wet or dry rot damage inside the roof envelope.

Your roof has no falls and sagging (perhaps damaged) joists. Whoever built it didn't know how to create falls so the roof appears literally flat.

Whoever laid the felt didn't have much more idea either.

Torch-on wont properly take to that surface - plus DIY torch-on could be dangerous for you and your roof.

If you go ahead and fake it then any competent surveyor or roofer inspection would instantly reveal it for a cover up.

 

[Kuffs]

Hi Ree, As I mentioned in my post, I am not a roofer, and I am questioning what my friend is suggesting we do to remedy the problem. Even I, as a none roofer can tell that it has problems with the joists. You are right about the water and mold, as the roofing joists are exposed in the garage. I have put a level on the under side of the joists, at right angles to them and there is fall, but the second to last joist before the point where the water runs of into the gutter has sagged/not been installed correctly in the first place. The fall at that point is actually in the opposite direction to the roof fall. The roof falls from one side to the other, as well as from end to end. To be fair to my friend, he has not seen the roof. I'm giving serious thought to ripping off the felt and making fills to correct the fall and bowed joists and then re-boarding in 18mm ply. He can then torch on the new felt for me. By doing this ill give him a decent roof structure to felt onto. The cost will then be only slightly higher than boarding straight over the felt. Thanks for your input.

 

[Richie1972]

Competent roofer should have that off and back on in a day,
Strip it off looks like it would be an easy strip