I have put a non breathable membrane to the back of the stud wall on the cold side is this wrong?

[Andy80]

I have fixed a full non breathable DPMembrane to the back of the stud wall on the cold side with a 50mm cavity before the brick wall, should this have been breathable? Will it pass building regs if I leave it ?

 

[jeds]

It's wrong and will cause condensation. My advice is remove it. You will be better off without it.

 

[Andy80]

I have fixed a full non breathable DPMembrane to the back of the stud wall on the cold side with a 50mm cavity before the brick wall, should this have been breathable? Will it pass building regs if I leave it ?

I will put a full vapor barrier on the warm side but trying to understand if I leave the cold side on or cut it off

 

[jeds]

And it won't (shouldn't) be signed off by BC!

 

[Andy80]

Thank you, I thought that may be the case, if I remove is it ok to leave it without any membrane an the cold side ?

 

[jeds]

As long as the cavity is well protected and not likely to become saturated it won't be a problem.

 

[Andy80]

Thanks, it’s a new single brick double garage ? Had no issues with any wetness or dam in the last three years ?

 

[Andy80]

I have stud walls which sit 50mm from a single brick wall, do you have to put breathable membrane on the back (cold side) if you are using kingspan insulation boards ?

 

[mrrusty]

It's a garage. You're worrying too much. It's only a condensation risk if you are generating warm damp air in the garage that can condense. In an unheated garage, condensation risk is minimal. If your garage is big enough for building regs, - >30sqm - then I'm not sure what the requirements for a garage are - I'm sure others will chip in or speak to your BC

 

[jeds]

? a garage. Out of interest, why are you dry lining a garage?

 

[Andy80]

I have put the breathable membrane on the back of the stud on the cold side and just realised i have installed with the printed side facing in! Will this cause issues or will i get away with leaving it? Using kingspan for insulation....