My VCL has some leaks, how big a deal is it?

[MisterBoy]

I put the plastic sheeting on my pitch roof VCL but haven't been able to progress further due to weather. Figured it meant the roof was weatherproof since VCL is stapled on top of the sub-deck.
In heavy rain we get leaks in 3-4 spots. Can't find why. No obvious holes or tears. No guarantee leak is where the water comes through ceiling since it might run down roof inside VCL looking for a way in.
The proper roof will prevent this but it means VCL is not perfect. Does it matter much? Foil-taped PIR will go on top. Maybe VCL is just belt&braces anyway.

 

[^woody^]

Pitch roofs don't have a vcl, so it's not a big deal at all.

 

[MisterBoy]

Mine does. BC demands it cos its a warm roof.

Back 2 the question...

 

[MisterBoy]

Unless this https://www.sigroofing.co.uk/info-h...-27/insightnews-flatroofing/wheres-that-leak/

Since no insulation yet could VCL be CAUSING problems not preventing them?

 

[^woody^]

Mine does. BC demands it cos its a warm roof.

Back 2 the question...

Then someone at your council and your designer do not understand how to specify and construct a pitched roof.

And BC can't "demand" jack if you know how to build.

If you are constructing an insulated pitched roof, then the only time a vcl is required is when insulation is within the roof structure. And in this case the vcl would be on the underside of the rafters - as like the name suggests, it controls vapour [from getting into the roof]

Back 2 the problem ...

 

[MisterBoy]

I just want to fix it.

Anyone know Is small leak in VCL a big deal, can I fix it when up there doing insulation?
I think maybe wind tore around a staple, maybe tape or patch with polythene sound reasonable?

 

[Leofric]

Do you actually mean a vapour control layer/vapour barrier/ vapour check ,or are you referring to a breathable membrane

 

[MisterBoy]

Do you actually mean a vapour control layer/vapour barrier/ vapour check ,or are you referring to a breathable membrane

Full barrier. Stops warm air reaching wooden top deck and condensing inside roof. Seems standard for warm roofs looking online.
Think breathable normally goes on cold side when insulation office roof not outside? Or cavity walls?

 

[^woody^]

Nope, a couple of vodkas are not helping at all. The mud sill has no clarity.

 

[MisterBoy]

Better duck this topic then leave it to them who understand.

 

[Nige F]

I just want to fix it.
patch with polythene sound reasonable?

To me it does sound reasonable - stuck with some silicon or roof seal - I patched a hole in 1960's slaters felt ( bitumenous) in my roof space. ( don't ask how it got there) sucessfully a couple of years ago with a patch "glued" on. Still OK this Christmas when I was up there

 

[Ian H]

To me it does sound reasonable - stuck with some silicon or roof seal - I patched a hole in 1960's slaters felt ( bitumenous) in my roof space. ( don't ask how it got there) sucessfully a couple of years ago with a patch "glued" on. Still OK this Christmas when I was up there

How did it get there?