Builders Share: Layer Upon Layer

It'll probably take a couple of weeks to get all the plastering done --again, the DIY dilemma of only being able to work on the project in my "spare" time-- so I'll go back to describing the work it took to get to this point.

Like in the downstairs walls, after I installed new electrical and plumbing service, I filled the stud bays with pink fiberglass bats on both the exterior walls (for insulation) and the partition walls (for soundproofing). I then installed 1" rigid foam board insulation over the top of the studs of the exterior walls. Downstairs I used 1/2" foam boards, but the 1" boards provide double the R-factor for about $6 more per sheet, and since I used fewer than 20 sheets upstairs, I've significantly increased the R-factor in my walls for less than the cost of two nights in a flea bag motel.

Putting the thicker foam boards on the upstairs walls meant an extra step in the rebuilding process though. With the 1/2" foam boards, I was able to mount the sheet rock right over the insulation using 2" drywall screws that could pass through both materials and anchor soundly to the wall studs. With 1" foam boards, sending a screw through 1-1/2" of material before reaching a wall stud wouldn't make for a strong enough wall; so I needed to install a layer of wood strapping over the insulation to provide a strong surface to mount the drywall to. The gap between the drywall and insulation created by the strapping is also a nice little dead air space that bumps up the R-factor of the wall a little more as well.