Roof valley lead

[StevieV1]

Hi all

When doing a valley in lead, does it have to be any specific width?

Also, is there a specific amount that the tile overlaps the lead or sufficiently to be watertight?

Thanks in advance

 

[yorkie1969]

Standard width is 400mm. If you get 450 wide lead you can turn 25mm back on each side to act as a return welt. Put pieces on no longer than 1.5 metres and lap over 150mm with each new piece. Code 4 is okay but it is worth paying a little extra to use code 5 as the valley will get a lot of water.Try and get a 100mm side lap (minimum 75mm) over the lead with your tiles. Ping a line to follow so it looks straight and true.
I would say 95% of valleys are the same width but it is worth measuring it just to check.
Good luck.

 

[Blagard]

There are plenty of details out there to help, as one example below. As yorkie has indicated the width is not "cast in stone" so I would look for a detail that is for your particular roof tile/slate
Lead Valley Detail

 

[StevieV1]

Thanks very much for your advice. 450mm lead it is then!