Poor workmanship causing internal leak

[dpllewis]

I need some advice on what I hope is an unusual situation - at least I hope few others are victims to such shoddy workmanship. You'll see from the picture below that the junction at the bottom of the roof tiles is the wrong way round - the liquid applied waterproofing on the flat roof runs up and over the tiles, not under them. Can you guess where the water goes? Yep, it runs off the tiles and goes behind the waterproofing and is causing an internal leak. We're left with this issue and cannot get the installers back to remedy it (don't ask!).

Dunlace Roof

• dpllewis
• 5 Feb 2017

What are my options here? I know the correct installation would see the tiles sit over the liquid applied waterproofing so the water runs off correctly, but this might be tricky here. Ideally we would like to avoid taking off all the tiles, and avoid scaffolding four floors up if possible (perhaps unlikely).

Is there a way of propping up the bottom tile and re-doing the bitumen? Is there a filler/foam? What other approaches are there? I'd be enormously grateful for advice here before asking roofers for quotes.

 

[freddiemercurystwin]

Anything that doesn't involve removing the tiles will fail. But you probably know that already.

 

[Doggit]

Oddly enough, what they've done is correct, but shoddy. They've used the sealer because the can't lift the bottom row of tiles, and would need to go up to at least the second row of tiles, in order to get the bottom ones out. What I wonder, is the ridge at the bottom of the tiles, which shouldn't be there. You don't by any chance have a "before" picture.

If the waterproofing has been applied properly, then any rain should come down the tiles, and then over across the roof, so where is the leak really coming from. I suspect they didn't know, and just applied the sealer to try and deal with it. As you can get access out on to the parapet, you should be able to work there without scaffolding - as long as the problem is with the tiles of course.

Where does the leak appear inside the room, and where does the rain run off the parapet to.

 

[datarebal]

The water will run between the bonds (butt joints) and under the black stuff.
What ever you do will involve at least two whole courses of slate.. Unless of course you used some alloy or lead soakers hung from the CDR,to take care of the bond. It will work untill the sealer unsticks...but I never suggested this method

 

[catlad]

What they have done is correct for moron's who give roofing a bad name.
No real fix here without removing the tiles.

 

[^woody^]

Oddly enough, what they've done is correct

Nonsense

Any cladding should always project over a roof covering or an upstand

 

[^woody^]

You need a flashing behind the bottom row of slate, and this should go over the upstand of the flat roof. Likewise for that window cill, but its going to be difficult on those corner posts, so some sort of double flashing with the topmost edge fixed and sealed.

 

[Doggit]

Nonsense

Having thought about some of the comments posted, I accept your criticism completely, and unreservedly.