Seeking advice on replacing lead on valleys.

[Munchincocopops]

Hi – I am looking to replace lead valleys as one failed (split) and I did not know until it bowed the bedroom ceiling.

Anyhow leak is temporary fixed but now I have decided to replace all 6 valleys.

I noticed the wood valley probably needs replacing and am thinking of 9mm OSB….is that ok.

Currently it looks like flooring T&G.

Also I expect the water got in as there is nothing below the lead on the valley.

So I’m after “belts and braces” solution and am thinking of new 9mm OSB valleys, new sarking underneath on top of 1.5mm Classicbond rubber running down the valley OSB and 2ft or so either side, then code 4 lead on top of that.

 

I’d appreciate any comments on this and can anyone recommend a good quality sarking.

 

 

The house was built in 1989 and the sarking is that bitumen based product that rots as it reaches the gutter. So I plan to fit new sarking under the old as it meets the gutter too.

 

 

I’m no roofer but I am a serious DIY who has bult a large garden room and I used Classicbond on OSB for that roof as it’s a 7 deg slope.

 

 

Thanks for any advice.

Edited 3 hours ago by Munchincocopops