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.

 

Sounds like my parents' house. Wartime modular construction. Their walls are 2" cavity with 3/8 ply GLUED on both sides. Great fun to work on. Rock lath on interiors and plaster. No sheetrock in a house that old. Its rock lath.

in their case, they have the black rockwool tar paper bag insulation that is really thin. Its practically worthless.

See if you can run a fish tape up the wall or if it catches on anything. They have lots of horizontal blocking and its a nightmare to fish anything. It would be impossible to reinsulate their place due to all the horizontal blocking.