Dormer Valley Detail

[Paul W12]

I noticed a damp patch on the sloping part of my bedroom ceiling under the dormer cheek and had a look on the roof and the where the dormer valley outfalls onto the main roof, some of the water seemed to be finding its way under the tiles, I've temporarily fixed this gap but does anyone know of a good guide showing detailed drawings that I can use to form the end of the valley correctly. I've seem plenty of drawings showing a valley terminating in a gutter but can't seem to find anything that covers a dormer valley outfalling onto a tiled roof

Thanks

 

[datarebal]

which tiles and what valley system do you have

 

[datarebal]

some images here pretty shoddy but gives the idea
https://www.google.co.uk/search?q=d...UIHY9hCasQ9QEwB3oECAEQNg#imgrc=BhQaALDFcHDdoM:

 

[Paul W12]

Thanks Datarebal,

I appear to have a grp valley that terminates in some lead work before discharging onto the roof tiles, tiles are double roman concrete tiles

 

[datarebal]

Sounds about right. Under the tiles each side of the valley,Check the edges of the lead are turned up to prevent water running side ways..
Other detailing is straightforward

 

[noseall]

I appear to have a grp valley that terminates in some lead work before discharging onto the roof tiles

Check the edges of the lead are turned up to prevent water running side ways

Here's one we did earlier....

Dormerlead1

• noseall
• 17 Nov 2019

Dormerlead2

• noseall
• 17 Nov 2019

Dormerlead3

• noseall
• 17 Nov 2019

 

[datarebal]

not much of a turn up there....will be running over the edge in a short time once the debris builds up.
cut the valley back more bring the lea over the batten higher up allows a better turn up

is that 19 x 38 batten btw?

 

[noseall]

is that 19 x 38 batten btw?

Yes, had to match the existing batten. All, on 400mm c/c (or less).

cut the valley back more bring the lea over the batten higher up allows a better turn up

Does bringing the lead over the batten mean that tile won't hook on though?

 

[datarebal]

try it next time... im not trying to pick.. but there is a finer way

 

[noseall]

try it next time... im not trying to pick.. but there is a finer way

I have never worked with a proper roofer so have had to learn everything by trial and error (and a smattering of common sense). Being of multi-trade background has its limits.