Leaking Valley

[Echovertex]

Hello

I had extention done on our bungalow about a year ago and had to form a box gutter between the two roofs, at the end of gutter there's a small valley. The roofer wasn't to sure on how to do this and the neatest way. He ended up doing some kind of lead valley underneath the tiles, which worked fine at first but has now started leaking! Just wondered if someone on here could help, what type of valley should be used, how it would work. The new roof is a 32 degree pitch and old 40 degree. Any advice would be great appreciated. Many thanks

 

[catlad]

Looking at the design, its not going to take a lot to block it and cause a dam.

 

[noseall]

Hello

I had extention done on our bungalow about a year ago and had to form a box gutter between the two roofs, at the end of gutter there's a small valley. The roofer wasn't to sure on how to do this and the neatest way. He ended up doing some kind of lead valley underneath the tiles, which worked fine at first but has now started leaking! Just wondered if someone on here could help, what type of valley should be used, how it would work. The new roof is a 32 degree pitch and old 40 degree. Any advice would be great appreciated. Many thanks View attachment 391900View attachment 391901View attachment 391902View attachment 391903View attachment 391904View attachment 391905

It's simply being overwhelmed due to its slightly thoughtless design. Fixable with some modification to the tile batten etc.

 

[Echovertex]

Thanks, would you recommend leaving as it is with lead valley beneath the tiles? And just changing the batterns around? What do you think about doing some kind of GRP valley?

 

[catlad]

Why has it not been designed as a standard open valley? I don't recognise those tiles, what make are they?

 

[Echovertex]

It's just what the roofer did, the architect didn't spec in detail for that. The tiles are Sandtoft 2020 Interlocking.

 

[noseall]

Thanks, would you recommend leaving as it is with lead valley beneath the tiles? And just changing the batterns around? What do you think about doing some kind of GRP valley?

We ALWAYS fix GRP dry valleys. This involves removing the valley tiles, removing the batten and felt, fitting support trays (level with the rafter tops) and reinstating the valley set up along with your new dry valley.
I cant see it being successful without doing something with the battens.

 

[datarebal]

The lead should have been fully supported .
An open valley used . What you see here we've seen many times on preformed grp "dry" valleys . Fitted by others as we don't use them.
The sandtoft 2020 is a good tile

 

[Echovertex]

Ok thanks, Would you recommend a traditional lead valley, supported with 12mm or 18mm ply? And cemented in? Would this have to be quite wide to take both roofs( see photo).