An older house often means older insulation.
This is a three-story, 1941 semi-detached, all brick, with a flat roof. It is typical construction for this era and in this place.
There are newer windows, but what appears to be original drywall. Original drywall means original insulation. What kind of insulation?
In the era between WW1 and WW2 typical brick wall construction was two layers thick, with the interior supporting wood structure tied into the exterior walls. This is a brick structure with a wood interior. In contrast, what is built now is a wood structure with a brick facade.
The wall studs in that era usually began just inside the brick. If there was anything between the brick and wood it was a vapor retarder usually of tar paper.
Insulation could have been anything from a rock wool (which is a slag that was spun into fibers), or fiberglass, or a light cellulose made from newspaper, or nothing!
Drywall began to be used in this era. It was thought in some circles that dead air framed by the brick on the outside and the drywall on the inside would serve as insulation. Like an igloo?
You've seen my igloo analogy before. The door on an igloo is intended to trap air and serve as an insulating buffer. Such dead air can provide some energy efficiency on the outside of the house, like with storm windows for example, but dead air inside the walls of a house provides little to no insulation. And can create an area rife with moisture.
Knowing all that I was exceptionally interested in seeing the thermal images of this 1941 house. The outdoor temperature at this time was about 45F.
All of the rooms felt cooler. And the room to room temperatures varied quite a bit.
These two images are of the same corner in this house, on the opposite side from the sun.
The left image is of the third-floor bedroom and the right the kitchen. You can see that the temperature in spots is not much warmer than the outdoor air.
The erratic and inferior wall insulation is evident in each image. Indeed, all of the rooms looked like this. Is there any insulation at all, or is it just thin and of a deteriorated thickness or quality?
My recommendation: while thermal imaging can reveal information, it sometimes does not answer questions. In fact, it might beg questions! What is going on inside the wall here? We don't know. But we do know why the rooms feel uncomfortably cool. Feeling cool during the winter would suggest that these rooms would feel warmer during the summer. So the HVAC system is in for some heavy lifting!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560