Is this blockwork ok?

[WWilts]

2 hours ago, tonyshouse said:

Insane, very draughty 

Noted. Sealing the internal face of the inner leaf seems doubly important, for airtightness. I'm told concave jointing is best for air tightness. Hope that's true.

 

Thermal conductivity of air at room temperature is reportedly 0.028 W/(m*K) [even lower at 0 degr C]. Mortar much higher thermal conductivity, over 1.000 W/m*K, even higher if saturated. 

[tonyshouse]

Trouble is future cracking, for me exposed blocks are unacceptable as if/when they crack there will be draughts, 

[WWilts]

47 minutes ago, tonyshouse said:

Trouble is future cracking, for me exposed blocks are unacceptable as if/when they crack there will be draughts,

Very true. Makes the quality of dabbing and taping critical if drylining is inevitable for various reasons. Preference for wet plaster is well understood, just not possible here for various reasons.

[Onoff]

What about a parge coat at least, on the internal block work? 

Edited October 4, 2021 by Onoff

[Onoff]

@recoveringbuilder , scrub that, @ToughButterCup didn't you slop on your page coat with a broom or similar?

Edited October 4, 2021 by Onoff

[WWilts]

Just realised that the small voids in the perpends of the inner leaf cavity face will likely be filled by the bonded EPS beads. Doesn't contribute to airtightness of the inner leaf, but improves thermal insulation a bit, compared to air.

[Onoff]

 

[WWilts]

Great stuff. If an approachable brickie / PM were not available, this is what any sensible person would do.