Cold Spots

“There was an iciness, a sinking, a sickening of the heart” – The Fall of the House of Usher by Edgar Allan Poe

It is a staple of horror stories and movies for the unwitting protagonist to feel an eerie chill that foreshadows a spooky threat to come. In ghost-hunting shows, investigators often have some sort of digital thermometer to prove to the warm, cozy viewers that they are experiencing the presence of the supernatural.

At Virginia Dwelling, we do not claim to have any special knowledge of the hereafter; nor do we wish to discredit the ghost-hunting profession. As a home inspector, however, I have a very different way of explaining random cold spots: they’re drafts.

Once upon a time, houses had little to no insulation, windows and doors closed but didn’t seal, and building practices were irregular at best. When the wind blew, the pressure differential exerted on different parts of the house along with the given arrangement of the interior space and the placement of doors and windows created an environment in which drafts could come from all sorts of different spots and shift dramatically.

Instead of air, think for a second about light in a house. How light is experienced in any given spot is the product of innumerable factors: the angle of the sun, which lights are on and where, what doors are open and how much. From any spot in the house, the light changes as any of these factors does: sometimes gradually, sometimes dramatically.

Now, think of the air in a house – a sufficiently old scary looking one. The movement of air due to interior and exterior forces isn’t that different. Open a window upstairs, you get one draft. Having a poor seal around the front door makes for a different one. With this understanding, the possibility that the cold spot in the dining room is not the spirit of a wrathful relative seeking to punish those who sold that terrible old china set can be entertained.

Wait! What about cold spots with no wind! Well, in the Old Gray House, and perhaps yours, the spotty insulation is partly to blame. For now, the insulation in the attic and walls is irregular at best. The original insulation has broken down unevenly, the additional insulation is erratic, and the first floor floors have no insulation at all.

The most important place to insulate in a house is the attic. Like your head, this is where the most heat gets lost, but insulating the walls and floors is important too. Go outside in shorts, t-shirt, and a really warm hat in the winter and this will suddenly make a lot of sense.

Below are pics from my adventure insulating under the office, probably the coldest room in the house. I’m very pleased with the results.

60 degrees isn’t terrible, but it’s colder than I’d like it to be.

60 degrees isn’t terrible, but it’s colder than I’d like it to be.

Who wouldn't want to explore this crawlspace!

Who wouldn’t want to explore this crawlspace!

I'm shooting the foundation wall. It was about 50 outside so you can see that the block foundation doesn’t really insulate.

I’m shooting the foundation wall. It was about 50 outside so you can see that the block foundation doesn’t really insulate.

I’m using batts of Owens Corning insulation (R-30, 9” – 10”). This is probably more than I need, but I really tired of having cold feet while I write blogs and home inspection reports!

I’m using batts of Owens Corning insulation (R-30, 9” – 10”). This is probably more than I need, but I really tired of having cold feet while I write blogs and home inspection reports!

A common mistake when installing insulation is over compressing it. As I explained in Winter Winds, insulation creates many layers of static air that resist thermal transfer. Notice how the insulation is the full depth of the joists.[1]

A common mistake when installing insulation is over compressing it. As I explained in Winter Winds, insulation creates many layers of static air that resist thermal transfer. Notice how the insulation is the full depth of the joists.[1]

The result. I’m more comfortable and, even if it's pennies, saving money. No need to touch the thermostat! -Joe

The result. I’m more comfortable and, even if it’s pennies, saving money. No need to touch the thermostat! -Joe

[1] The boards that support the sub-floor.