leak valley (i think)

[Ciaransmith]

morning guys,

need some help, we have a leak in bedroom that sit roughly under the valley, I've been in the loft and can see a wet line under the lead/wood support from about half way up that runs down and drips down the bottom. I can't see into locate the leak due to how it's constructed. These are pics from outside, can somebody suggest where I should start looking?

regards
C

 

[Ciaransmith]

the gaps on the ridge tiles have seen filled in to rule that out

 

[Cubist]

A couple of possibilities both associated with driven and heavy rain come to mind. First may be water forced back under a damaged or loose tile. The second being water forced back under one of the lead leaves of the valley.

 

[Ciaransmith]

by lead leave you mean the overlaping lead? if so how would you solve that, mastic is down? as for loose tiles, I'm assuming just give them a wiggle and see

 

[Ciaransmith]

closer inspection, the lead at the edge looks open to water running down, I'm guessing it should look like this?

 

[Cubist]

by lead leave you mean the overlaping lead? if so how would you solve that, mastic is down? as for loose tiles, I'm assuming just give them a wiggle and see

Yes. A mastic pushed under the leading edge would prevent/limit driven rain penetration. As far as the tiles are concerned they need to be properly seated against their neighbours.

closer inspection, the lead at the edge looks open to water running down, I'm guessing it should look like this?

The photo is particularly clear but, to my poor eyes, it looks like edge at the side of the lead is open. The lead should have been installed beneath the mortar - in effect the lead would be embedded in the mortar and not left free.

 

[Ciaransmith]

for the edge that potentially is exposed would mastic be a temp fix until it can be sorted next year?

 

[Ciaransmith]

looks to be under the mortar, but has some random cracks along the way. would again these with mastic temp fix?

 

[Cubist]

looks to be under the mortar, but has some random cracks along the way. would again these with mastic temp fix?

Yes, and gently smooth it with a wet finger end but don't press too firmly - you could make the problem worse.

 

[fernicarry]

I had a pinhole leak in a lead valley. Only noticed it because I'd taken down the ceiling below and at certain angles I saw a flash of daylight. I had attributed the wetness to a badly detailed overflow pipe nearby, but with that deleted the wetness was still there. Was hard to find it on the outside in order to patch it. Something like that wouldn't be at all obvious from a photograph.

 

[Ciaransmith]

I hope that's not the case and it's simply filling the holes in

 

[fernicarry]

Given that lead expands and contracts by quite an amount (that's why the valley is done in several overlapping lengths not one continuous piece) the junction with the mortar will always be on the move so it will never be truly watertight. But it seems like you are relying on that fillet of mortar to direct the run off from the edge of the tiles into the valley. Round here we don't seal the slates on to the valley, they just overhang by a few inches.

 

[Ciaransmith]

Tbh I did find that abit weird I'm no expert but I would have thought the tiles would have a little overhang with the mortar pushed right in, so gravity would take care of most of the water running down and not run down the mortar. I'm Derbyshire and most houses seem to be this method, so must work