Exterior block wall options

[ScotcH]

Starting construction soon ... one last decision to make.

Given everything else being equal, which of these 2 wall designs would be the better option? Is the 1" air (pink stuff) just basically a waste of space, and would the single leaf design be similar, or even better? What about the concrete block wall itself ... does it already act as a 2 leaf because it's hollow blocks, or does the mass of the blocks, and the fact that the air gap is not contiguous negate that?

[Starlight]

Your question about the air gap seems to be a continuation of your other topics, Contrary information? and Basement studio/drum room advice needed, where you have plenty of helpful advice from Jag94 and others. If your final drawing, version 2, in the latter topic is still correct then the gap will be necessary to create the room within a room, otherwise no gap simply means the inner and outer rooms are touching, negating all the work on the other 3 walls and ceiling.

The concrete blocks act as a single leaf because there us no gap between them, there are just gaps inside them; they are still connected, still touching.

[ScotcH]

Source of the post Your question about the air gap seems to be a continuation of your other topics, Contrary information? and Basement studio/drum room advice needed, where you have plenty of helpful advice from Jag94 and others. If your final drawing, version 2, in the latter topic is still correct then the gap will be necessary to create the room within a room, otherwise no gap simply means the inner and outer rooms are touching, negating all the work on the other 3 walls and ceiling.

The concrete blocks act as a single leaf because there us no gap between them, there are just gaps inside them; they are still connected, still touching.

And this is why I post here ... you make excellent points that I did not consider. And a valuable lesson: Can't just consider a single point in the design, must take it as a whole! Thanks for that.

I'll post an updated design in the main thread.