valleys: felt on top of \ or under the boards

[luk4sh31]

Hello.

 

I have new valley installed last year for extension and the roofers put membrane on top of the boards before lead work. I was told recnelty that you should not used breathable felt on top of the valleys when laying lead. Can someone else share their views in this matter. thanks 

 

[Dave Jones]

grp valleys are better than lead and cheaper.

 

no issue with membrane below a valley. belt and braces etc

[nod]

Most of the housing associations insist on a length of 600 dpc under the Fibre glass 

Lead is more expensive but far better than fiberglass You can walk up lead also 

[Temp]

6 hours ago, luk4sh31 said:

Hello.

 

I have new valley installed last year for extension and the roofers put membrane on top of the boards before lead work. I was told recnelty that you should not used breathable felt on top of the valleys when laying lead. Can someone else share their views in this matter. thanks 

 

 

I thought the membrane should drape in to the valley gutter, so any rain or snow blown under tiles runs down into the valley gutters.

 

[makie]

5 hours ago, Dave Jones said:

grp valleys are better than lead and cheaper.

 

no issue with membrane below a valley. belt and braces etc

 

There is, breathable membrane should never be used under lead as it sweats badly. Lead manufacturers recommend building paper.

[makie]

25 minutes ago, Temp said:

 

I thought the membrane should drape in to the valley gutter, so any rain or snow blown under tiles runs down into the valley gutters.

 

 

You should have a run of membrane under the the valley and then membrane should lap the grp/lead etc