Drylining airtightness advice

[bmj1]

Hi all,

 

We've got our shell erected, brick and block cavity wall construction.

 

I'm looking to retroactively bring our wall u values up, and it looks like drylining with insulated plasterboard is the only realistic option.

 

I was previously hoping to use wet plaster for the "easy" air tightness, but this doesn't appear to be feasible...

 

Any recommendations for how we can best ensure we get decent air tightness with insulated plasterboard dot and dabbed onto concrete blocks?

 

Parge coat?

Tape applied where?

 

If anyone can give me a bullet proof spec, that would be awesome.

 

Thank you in advance

[nod]

Many on here swear by Parge But from an airtightness point of view it’s a waste of time 

It’s better to make sure that the continuous lines of dab are applied around all perimeters sockets and window reveals Acoustic sealant should be applied to ceiling edges also 

and before you start make sure all joist ends are pointed in tight 

Pink backed PBS for dabbing 

Edited May 22, 2023 by nod

[Big Jimbo]

I want @nod to do my dot n dab.

[bmj1]

16 hours ago, nod said:

Many on here swear by Parge But from an airtightness point of view it’s a waste of time 

It’s better to make sure that the continuous lines of dab are applied around all perimeters sockets and window reveals Acoustic sealant should be applied to ceiling edges also 

and before you start make sure all joist ends are pointed in tight 

Pink backed PBS for dabbing 

 

wow, awesome, thank you. This should be easy enough to specify and explain with your picture and comments

[nod]

14 minutes ago, bmj1 said:

 

wow, awesome, thank you. This should be easy enough to specify and explain with your picture and comments

Your welcome 

Simply repeat around the house 

Window reveals and heads 

Parge won’t do any harm Your only looking an afternoon for two spreads to do a four bed home

But don’t refer to it as an airtightness layer 

It will say on the bags Sound coat 

As soon as you say airtightness They won’t bother solid dabbing the angles 

 

Most of The properties that I dot and dab have to achieve a rating of 2 

Whilst they big builder saint test many 

They do test some and we never know which ones 

 

 Good luck 

[Big Jimbo]

The problem with @nod is that i think he is a blinking Northerner. Not that i am against them. My wife is One. Just that he ain't coming down to sunny Hertfordshire on the promise of a packet of Hob Nobs is he ?