Non-motoring > Repairing roofing felt overlap Miscellaneous
Thread Author: smokie Replies: 11

 Repairing roofing felt overlap - smokie
My (rather poor) neighbour had her side of the adjoining extended garage roof re-felted a year or so back. It may or may not be related but I have water leaking down the common wall. So I got up and had a look.

There is an overlapping piece of felt the whole length of the roof (probably 40ft), about 18" wide. It doesn't seem well stuck down on my side, so it could be the culprit. It was clearly put in when her roof was done, but I don't really want to pursue it with the neighbour, nor do I want to pay a roofer to do it.

I can lift at least 2 inches of it so could put some stuff (adhesive maybe) under it and press it down rather than trying to go along an edge.

Does anyone any recommendation for a product to seal the joint better? It would need to be able to be applied to wet felt (as it won't be drying out anytime soon I imagine!), and reasonably easy to apply? I have used those sealants in tubes but found them quite messy to use, and to get enough would probably be quite expensive, so I'm wondering what product might be easier to apply (brush or trowel maybe). I don't want to spend an arm and a leg because it may not be the problem, but I want to do a half decent job...

 Repairing roofing felt overlap - Kevin
I used Black Jack bitumen paint and bitumen roll to seal the joints, underside and felt roof of her garden shed. That's over 10yrs ago and there's no sign of water ingress or rot yet.
 Repairing roofing felt overlap - Manatee
Is a flat roof with a wooden deck that the water has got into? If so it will need stripping, drying/repairing and refelting, Shirley? I hope I've got the wrong end of the stick. Are you sure it's got in at the overlap? Once it gets on the deck it can come out somewhere else. The flashing where it joins her house for example. Is the party wall in question the one that separates your two garages?

There are gun sealants that claim to work wet or dry. I haven't tried any of them.

adiseal.com/repair-felt-roof/#:~:text=Adiseal%20is%20a%20remarkable%20adhesive,roof%2C%20even%20during%20rainy%20weather.

I've done a couple of roofs with bituminous felt but only on sheds, where the fall negates the need for a leakproof sealant. I had a flat roof replaced on the bungalow with butyl sheet which is a lot better if properly installed. It was still good at 20 years when we demolished the bunglyhole for other reasons.

 Repairing roofing felt overlap - CGNorwich
Felted roof will only last 10 years or so. If it’s older than that it needs replacing. Do it sooner rather than later, it will only get worse. If you are lucky the wooden deck beneath will be OK. Otherwise that too might need replacement. If it does make sure marine quality ply is used. Butyl rubber will last a lot longer than felt - about 50 years so go for that if you can afford it.
 Repairing roofing felt overlap - smokie
Yer well - I know the proper answer is stripping re-felting and £££s.

Which is all very well till she has another leak on her side and gets some other cowboy in to fix it who wrecks my side in the process.

My side of the roof is well past it's sell by but generally looks pretty good. it was done as an insurance job I don't know how long ago, but was done properly.

When I come to replace it, I'm expecting it will be a big expensive job as the back half is my extended kitchen and it needs better insulation so probably change the height of the ceiling but a few inches etc etc. I'd also probably use the rubber stuff as we had the other flat roof done with that and it seems to have lasted really well so far (12+ years).

However I have a new bathroom being fitted before Xmas which is soaking up my money at a rate of knots, so I am not in a position to spend loads on the roof at the moment (and not really at this time of year anyway). That's why I asked for cheap options!! :-)

I realise the leak is possibly nowhere near where I'm seeing the leak which is another reason for not wanting to spend too much - I am addressing what I think might be the problem but don't want to waste too many £££s in case it isn't!

The water is coming in into the passageway which goes front to back of the extended bit so isn't really much of a problem in itself - and may only have come about due to the storms last week, which I missed, being in Portugal :-)

So Kevin's Black Jack stuff is looking favourite atm!! I'd already found the goo but searching bitumen roll has brought up some other interesting products.
Last edited by: smokie on Mon 6 Nov 23 at 16:21
 Repairing roofing felt overlap - CGNorwich
Well let's hope you get lucky. All the best.
 Repairing roofing felt overlap - smokie
Thanks, but it's not a matter of being lucky - my roof is, I believe, in reasonably good condition (and has at least another year or so in it) and it seems the current problem is due to work carried out on the adjacent roof, not mine.
 Repairing roofing felt overlap - sooty123
Best hope your next door neighbour is lucky then, for your sake ;)
 Repairing roofing felt overlap - Biggles
If you were to place a length of wood underneath the edge, would this be enough to stop any water flow from her side to yours?
 Repairing roofing felt overlap - smokie
Previously when ours was done our man put a small something to make a ridge between the roofs so that water from one couldn't bother the other. I'm not sure if that's still there, but I think the water now coming through my ceiling is because of them putting this strip of felt along the length of the roof to cover the meeting of our roofs but not sticking my side of it down very well.

Her side has a large puddle of standing water on it. It has no stones, whereas mine has stones (and probably less standing water!). I believe no stones is now and option, so I'm not being critical of that. But some areas of hers are lie a patchwork quilt where the bloke has skimped on felt. I can easily see it all from my landing window whereas she has frosted glass so probably can't.

When she told me she was getting it done I asked her to get both priced up as it'd be cheaper to do them both at once. But seeing the workmanship I'm glad she didn't ever bother with that!!
 Repairing roofing felt overlap - Fullchat
Flashband is good for sealing joints and holes.

Also spotted this product which claims to be able to be applied on damp material:

tinyurl.com/ywrmhchv

 Repairing roofing felt overlap - smokie
Thanks. Most of the tapes reviews (where I've found them) have a few saying it didn't stick. Gorilla stuff is generally pretty good though, I'll bear it in mind.

After rooting around for some time I've ordered a £25 pot of tinyurl.com/mr376xr7- looks brushable and can be applied to damp surfaces. Hope it does the job!!
Last edited by: smokie on Tue 7 Nov 23 at 00:08
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