General Suburban Updates and Rumours

[ijmorlan]

Just a single data point (well, 2 data points), but the townhouses I have lived in had common walls made of a single layer of concrete blocks with drywall glued directly on. Excellent sound transmission (which is bad, obviously), although probably OK for fire isolation.

I suspect that year of construction is strongly correlated with method of construction, but I don’t actually know anything about this.

I'm certainly no building expert, but you're right that probably provides some measure of sound insulation. To be honest, I'm a bit surprised that's a valid form of construction, drywall is a product that cannot touch moisture, while brick/concrete is a pourous material that can transmit water (even from the ground), so I wouldn't think gluing drywall to brick would be ... a good idea.

Actually my point is that it transmits sound just fine. Sound goes directly through the drywall to the blocks and then into the room on the other side of the wall. What is needed is mechanical separation (ideally, a small air gap, together with appropriate sound deadening materials).

I don’t know if there is a problem with moisture. The walls in question are entirely interior so there shouldn’t be any way for moisture to get into them; they’re built on concrete foundations (also interior) and are also closed at the ends and top — the outside walls and roofs are either continuous from one unit to the next or job over/up/down but in any case unless there is a leak there is no way for water to get to the concrete block.