Here I am down a rabbit hole called air tightness ?.    I understand that as an alternative to wet plaster you can get your walls sprayed with closed cell foam.   That would seem to be an attractive option as it would also add an additional layer of insulation.  No idea how it compares on cost with wet plaster though.

 

Anybody done this or have any pertinent info on this idea?

What product are you thinking of? 

I used a closed-cell, foam insulation, sprayed on to some internal steel columns, to exclude them from the thermal envelope and stop any risk of moisture getting to the cold, steel columns.

It was very expensive in compared to the blown cellulose fibre I used elsewhere. Very difficult to control thickness - I over-sprayed and then trimmed back to the thickness I wanted. Difficult to contain, ie. if you spray in, to full-fill an enclosed timber structure, even with well-screwed ply on C24 studs, the expansion will "pop" open the timber structure.

 

 

Edited November 16, 20214 yr by IanR

I’ve just spoken to a contractor who told me that at the thicknesses we would talking about there would be no insulation effect and it would be a lot more expensive than wet plaster.   So back to plan A I think !