Roof repair not worked that well

[trevorbayliss]

I have a flat valley about 50cm wide dividing two semis on the roof.

I had a crack in the valley where another valley runs into it. The valley is felted, but is older.

So i coated this valley in fibrepol (a sticky water proof paint solution with fibres) and it looked like it helped improve the thickness of the felt covering.

After this (a few days later) i stuck a patch of lead over the cracked area to sort of do a puncture repair on the roof.

However, the stixall i used didn't adhere and the lead just peeled up when i tugged it.

So i cleaned off the lead and applied the CT1 adhesive and this stuck a lot better.

Today has been the first day of rain for quite a few weeks and the leak is still there, but is much improved.

So i need to reattached this lead patch again as it must be letting water in underneath it.

What other product could i use to get the lead to stick down ? Would leadmate be a better bet ?

Replacing the whole run of felt is most likely the best option, but I dont think the block of flats has enough money to take it up and reslate around the lower sections draining into this valley.

I have a video showing the water running down into the area, but i cant load it on here.

 

[oldbutnotdead]

You may find that water is getting under the felt above the area you're playing with- if it's failed in one spot it's probably failed in others
Felt has a finite life, glueing patches on felt is never going to give a long term fix.
You/they may want to bite the bullet and price for a proper repair (lead would be favourite, for that area material costs will be low compared to labour).

 

[trevorbayliss]

I think it might be a rubber system, not felt, but anyway it has failed.

Got some patch up advice and he said to use fibreglass and resin over it. Sand it back a lot and then lay the fibre glass over the bad area and resin over.

It's much cheaper than having to replace the whole valley. The flats just dont have any money to do a proper repair. So we need a solution.

I was hoping leadmate might just do the trick.

 

[tell80]

Why not show pics of the whole area you have mentioned above?

FWIW: nothing is cheap if it doesn't work.

 

[Nige F]

Why not show pics of the whole area you have mentioned above?

FWIW: nothing is cheap if it doesn't work.

Wise words

 

[oldbutnotdead]

GRP (fibreglass) won't bond to felt, probably won't bond to rubber either.
Problem you have with patching from above is you are fighting gravity- with a patch the seal has to be perfect.
If it is a rubber system there will be better patch options but if it's reached end of life you'll be patching forever.

 

[trevorbayliss]

Well it has helped by 70% and a small bucket will collect any water coming into this loft void now but I want to try get it sorted properly.

I have a video but you can’t load them here

This is the only photo I have and the issue is at the bottom of the valley as you look down onto the dorma roof. It runs into a big flat valley and the leak comes in on the left side of the big valley where my gun is. You can see my lead patch, and this is tucked under the rubber valley coming down.

 

[oldbutnotdead]

Mmm. With the age of those slates I'm surprised there isn't lead up there
Ripping and tingling that lot to effect a full repair wouldn't be fun, probably lose a load from breakages. Unless you were 'lucky' and find they used cut nails and they've rusted out....
With your next patch you might want to try getting under the narrow valley felt/whatever but it's a high risk option (might make things worse if the felt goes under the slate verges on the valley)

 

[tell80]

OP,
Presumably you live in the dormer flat - whats to stop you from stepping out and taking pics of all three valleys, and the front apron area of the dormer?

The valley in question has had a previous lead repair piece higher up and the other valley isn't shown.
The dormer apron upstand LH wraps around to the dormer cheek incorrectly.
The slates below the dormer apron LH side are a bit jumbled.

The valley in question has perished - its finished.
The box valley was wrongly constructed in the first place.
The junction of all three valleys was also badly constructed.
Roof leaks can occur anywhere & present somewhere else.

Sooner maybe than later, you will have to get a roofer up there for a pro opinion - once a roof starts to go then its one thing after another.
Cleanly stripping most of the slates is easy enough to do without breakages - if the roofs are fully stripped then a modern installation would be with insulation and felt etc.

 

[trevorbayliss]

Can you see the patch ? I managed to lift the rubber narrow valley at the joint and push the lead about 10mm upwards to give it a little lap.

I didnt want to go higher in case i created more problems. I use a sealant on this join as well.

Its a 1890 aged building converted into flats in 1985. So i think any roof work might have been done around the time of conversion. The dorma was done then as well and this is what it looked like the other week.

I’ve repaired a fair few slates this last week as well, but I just don’t want to have to tackle that valley. Lots of issues like you say. Plus would need the other block to chip in and pay. So a whole load of admin issues.

 

[trevorbayliss]

OP,
Presumably you live in the dormer flat - whats to stop you from stepping out and taking pics of all three valleys, and the front apron area of the dormer?

The valley in question has had a previous lead repair piece higher up and the other valley isn't shown.
The dormer apron upstand LH wraps around to the dormer cheek incorrectly.
The slates below the dormer apron LH side are a bit jumbled.

The valley in question has perished - its finished.
The box valley was wrongly constructed in the first place.
The junction of all three valleys was also badly constructed.
Roof leaks can occur anywhere & present somewhere else.

Sooner maybe than later, you will have to get a roofer up there for a pro opinion - once a roof starts to go then its one thing after another.
Cleanly stripping most of the slates is easy enough to do without breakages - if the roofs are fully stripped then a modern installation would be with insulation and felt etc.

The flat is fully ripped out and I will be renting it out so no one there at the mo, but i can take photos.

I'm not a roofer, but i ended up doing the dorma in fiberglass but the roof was done first and then it was decided to do the slates again. So yes ideally the lead apron would be under the facia, but I couldnt change it. The previous dorma was wrapped in bitumen type paper just nailed to the OSB cheeks, then slates hung off the OSB. Ive wrapped it in a membrane, battened it out and notched the battens. Then new slates have gone on.

It is pretty sound all round so no issues should be popping up.

The valley does fill with water when heavy rain. My mate who owns one of the flats is a surveyor and he was thinking the issue is water is spilling up on the sides of the valley and in that way, but I think it is still the damaged section of valley where i have stuck the lead patch.

I really want to know if leadmate is a better product to use than CT1 adhesive and stixall. A roofer i know uses stixall for roofing for many bodge jobs so i have seen it uses well on slates. It didnt bond well with the lead though.

Ive applied a coat of fibrepol to this valley as well and the leak is much better, but still there.

So any idea on leadmate compared to CT1 adhesive ? Any better. For £10 i have to try it out first before we decide to rip it all off and get into all the issues with the neighbour paying etc.

 

[tell80]

You made quite a good job of renewing the dormer - well done.
However, I think you've got the location of the lead apron I mentioned wrong? The bottom of the outside corner where lead wraps around the corner is where i meant - moisture could be going behind it?

I've no opinion on adhesives for your purpose but definitely not leadmate.

 

[trevorbayliss]

I think the flashing will be ok. That break is there for expansion. Some sealant behind it will work if it becomes an issue.

Thanks all for opinions

 

[DAZB]

It may be nothing but looking at your photo of the dormer it looks like the lead below the white fascia has a gap to it on the left side and the fascia should ideally sit over the lead whereas it looks like it is butted up to it. Could this be the entry point over the roof edge and water is travelling down the inner timbers ?
p.s If you are nr Leeds I don't mind having a closer look for you. F.O.C

 

[trevorbayliss]

No the leak is damaged felt and is 2 yrs old. The dorma refit was nothing to do with it but yes the lead would be tucked under the facia but it was decided to do the sides after the roof went on.

So I have a small gap but have left it for now. A silicone bead will sort it out if an issue