Roof leak - trying to find source

Lewis_Benson

Hi folks,

Trying to find the source of a leak on my roof becoming more frustrating every day.

The house is an L shaped bungalow, cottage style, guessing 40s build, extention added around 2000.

So I have a leak on an inside corner, south facing,

https://youtube.com/shorts/E-_DL3Xeqvs?feature=share

It started as a stain on the wall, where the light switch is in the video.

I initially thought it was Condensation coming from the bathroom, but then I discovered there was water coming down the outside wall in the corner from behind thw facsia, I pulled off the gutter and to me it looked like the water was running off the roof tiles and wicking up underneath the end of the lead valley and down behind the gutter, onto the wall, and running down both thw outside and inside of thw wall.

I can't find any wet timbers in the attic, the only moisture I can find is If I pull back the attic insulation and get my hand down to the top of the concrete wall right down in the corner, which is where I was assuming the water was coming in behind the gutter.

I mixed a small bit of sand and cement and stuffed some under the end of the lead valley so that any water running off the tiles couldn't get behind the gutter, I thought problem solved.

About 3 days later we had heavy rain and I could see no water running down the outside so thought all was good. Unfortunately I started to notice water spots the living room wall, which is just inside the door where the water marks are at the start of the video.

I was trying to think back to when this started, and the only thing I could think of, was around the time the solar panels were installed back in February.

I called the installers and got them out to have a look, they could not see any issues with the panel install and pointed out to me that there was a crack about halfway up the lead valley.

So as a trial and error I put some bitumen roof sealer on it to see if it would stop the leak, unfortunately it didn't, as the water spots grew and new ones appeared.

I called a local roofer who lives nearby, he took a look and decided to try cutting the lead whee the crack is and put in a new sleeve of lead to cover it, he removed a number of the tiles to do it properly. the new section of lead goes about 6 inches under the upper section, and 6 inches over the lower section so the crack is well covered off.

He put some expanding foam under the tiles where he had to knock out the existing pointing, and repointed with fresh morter.

For a few days this seemed to be all good, we had some very heavy rain last Friday night and I couldn't see any water coming in, so was hopeful.

For the next few days all seemed good. Then we got some light rain and southerly wind one of the nights this week, and I could see a "snail trail" of water coming down along the door frame, where you see at the beginning of the video.

It's such a small amount of water coming in, which in a way is frustrating, if it was pouring in, it would be easier to find.

The roofer is away on holidays for a few days now so can't get him back for another week.

Anyone any ideas where else I should be looking, I am at a loss now.

brokenbad

Had a leak issue a few years back where there was droplets on the floor in the hallway which were coming from the ceiling during periods of heavy or windswept rain. Upon further investigation in the attic i found one of the ceiling slabs had moisture on it and managed to trace it back to a tiny gap in the tiles where rainwater was seeping in. I ran a piece of string through the gap so i would know exactly where to re-point the tiles on the outside. Once this was done, the issue never re-occurred.

Suggest getting into the attic next time it rains and explore the area above the doorway and try and trace it back to the source - maybe use a damp meter if you can get one. Look around for any areas where outside light is getting in with the attic light turned off.

GreeBo

lay some newspaper in the attic as its helpful to spot a small leak rather than on insulation or even wood floor.

I had a similar issue during windy rain and the leak was much higher up the valley, running down the valley rafter and out under the gutter into the soffit.

I had similar staining on the exterior wall and traced it back to this. Valley rafter and soffit were rotten and soft :(

iwillhtfu

Looking at your video it would be hard not to see it being related to the solar panels.

Water is likely coming through at one of the points they cut the tile and running down the felt or roof trusses and finding the ceiling over your door. It's certainly worth a look, I had a roof leak appear in a front bedroom when the cause was further back on the roof.

Does the timeline match up with the PV and staining appearing? Could be a number of months after the install.

10-10-20

Is there a hint that the water is discoloured yellow slightly? Sometimes that can be soot, but other times it's leachate or tannins from the wood suggesting perhaps that the water is penetrating the wood for a long duration of time and it's not just a run-off issue?

Guessing from a distance and agreeing with the previous posters, I'm going to suggest that one of the tiles got moved and affected the lead guttering alright. I think this is why SEAI wanted 600mm between solar panels and the edge of the roof though!

GreeBo

https://www.boards.ie/discussion/comment/120964656#Comment_120964656

Thats exactly what I had, outside corner of exterior wall was yellowing and traced it back to water running down the valley and through the fascia /soffit area.

Previous owners had painted the wall but not addressed the leak!

listermint

It'd very inclined to check the ridge tiles for cracks or damage. It can happen from people sitting on them perhaps installers. When they crack or have a gap in then old membrane is useless for keeping water out and water will trail down any of your rafters and drop down at any point along it a nail or anything even down to the base plate.

Its the first place I'd discount rather than pulling up valleys.

GreeBo

I found my issue by being up in the attic during the rain with news paper under the entire length of the valley. When the rain was heavy enough the water would drip off the valley rafters and other than the lead on top there was nothing to direct it into the gutter, the old membrane didnt overlap enough/at all or was broken down in the valley.

You should also be able to tell just by looking in the attic, the timber will be either wet or stained or both.

BrokenJetpack

https://www.boards.ie/discussion/comment/120967002#Comment_120967002

How did you fix the problem?

GreeBo

https://www.boards.ie/discussion/comment/121331396#Comment_121331396

Well I was reroofing anyway, but you would need to get they valley redone, if indeed thats the problem.