I called a contractor specializing in insulation of walls and he asked me to check if my walls are insulated. The background: My house was part of exhibit featuring the world of tomorrow at the 1939 World Fair in NY. Its purpose was to showcase modular house assembly. Soon after the fair was over, it was disassembled, transported to its current location and reassembled. It is a very pretty small house, but the problem is that my heating bill is too high. I think its walls are thinner than the ones in the regular houses and I get drafts from the bottom, where they meet the floor surfaces and also the electrical outlets. Here are the results of my investigation: I made a quarter-size hole in the wall. The outer layer was a regular plaster, I believe it is called sheetrock. That is placed over plywood. Once I went through the plywood, there is about an inch/inch and a half of air and then I hit another layer of plywood. There is no insulation in the empty space between the two layers of plywood. To recap, it goes like this (from inside out): Sheetrock, plywood, one-one and and a half inch of air, plywood, siding. I did not poke a hole into the exterior piece of plywood, because my goal was to find traces of insulation. The questions are: 1. Does this make sense? If not, where would be the place(s) to double check? 2. Does it make sense to fill with insulation the space where there is only air? I honestly expected to be wider if my walls were uninsulated. 3. Is there anything else I should be looking for/at. Thanks in advance. P.S. The hole I made was located about a foot and a half above the floor.

hi all. I installed a new bathtub and plan to use a glue up tub surround. I have green board to install around the tub for backing. question is should I mud and tape it or use something else to seal the screw heads and seams? the glue pl700 says it sticks to green board. it doesn't say anything about drywall mud or paint. thanks. Jay.