Airtightness for Durisol, Velox, Isotex builds

[Grendel]

Hello all

We are up to wall plate of our build in Leicestershire and wondering how to sort out airtightness.

It's an ICF Velox build so a solid airtight concrete layer, but the Velox blocks are quite an open weave of mineralised woodfibres.

Our experience of wet plaster on Velox in an outbuilding is that it took years to dry out.

Has anyone used a spray like purple passive or blower-proof liquid on Velox, Durisol or Isotex. Or how did you sort out internal airtightness?

 

Any suggestions?

thanks

[Russell griffiths]

https://www.british-gypsum.com/~/media/Files/British-Gypsum/Brochures-and-Leaflets/Product-information/Gyproc-Soundcoat-Plus-Brochure.pdf

[tonyshouse]

We plaster should be ok , need to hermetically seal to adjoining air tightness layers , need to eliminate air ingress round joists and in any first floor void and any penetrations 

[Grendel]

1 hour ago, Russell griffiths said:

https://www.british-gypsum.com/~/media/Files/British-Gypsum/Brochures-and-Leaflets/Product-information/Gyproc-Soundcoat-Plus-Brochure.pdf

 

Thanks Russell, a parge coat might be best given the porosity of the velox, if Purple Passive can gaurantee the air tightness then

30 minutes ago, tonyshouse said:

We plaster should be ok , need to hermetically seal to adjoining air tightness layers , need to eliminate air ingress round joists and in any first floor void and any penetrations 

 

We were looking at alternatives to wet plaster. Agree it's an effective method but we are looking for a dryer method to avoid bringing so much water into the building structure

[tonyshouse]

Most such methods result in colanders, very draughty and huge heat losses - beware