Uncovering the Secrets of an Old House
I've been in a lot of old houses and seen a lot of interesting things. One of the things I love about that is trying to figure out the mysteries I find. Lately, the mysteries I've been encountering are in…
attic
Is Venting an Unconditioned Attic Necessary?
Let’s talk about the controversial issue of venting an unconditioned attic with outdoor air. It's easy to confuse causes and symptoms sometimes, and that happens a lot with attic ventilation. I'll say upfront, though, that the International Residential Code requires…
Can Cold Surfaces Wring Moisture From Dry Air?
Cold air is dry air, right? Think about the humidity in your house in winter compared to what it is in summer. If you're in a humid climate, it's going to be drier in winter. Even in dry climates, it's…
A Frosty Heat Loss Puzzler
My house exhibits an interesting phenomenon on occasion. A lot of people who understand building science sometimes jump to the wrong conclusion when they see it. Hey, I did the same thing myself at first, too. The puzzle lies in…
Is Wind Washing Reducing Your Insulation R-Value?
You'd think that after more than 12 years and a thousand-plus articles, I'd have mentioned all the major building science terms by now. Yet, here we are. I just did a search of all the articles in this blog and…
What Is a Cold Roof in a Hot Climate?
For those of us who live in warm or hot climates, this question about roof temperature is confusing. A lot of people talk about cold roofs and hot roofs, and unfortunately, it's not just about the time of year, current…
4 Ways to Fix Your Duct System
I've written a lot of articles about ducts here, but I haven't yet addressed today's topic: common problems with ducts and how to fix them. This one is for homeowners or renters who want to save money and be more…
Air Sealing an Attic Access the Right Way
Attic access points can be a mind-blowing thermal liability. If you don't believe me, open the pulldown stairs or scuttle hole and go into an attic on a cold day. Then turn around and look down through the hole. You'll…
Frost in the Attic Has an Obvious Cause
If you've ever seen frost in the attic in winter, it's pretty to easy to understand why it's happening. It's the same thing that causes morning dew on the grass, frost on the exposed half of my car, or water…
The 3 Safest Ways to Insulate the Top of the House
I recently finished writing the chapter on the interaction of structure and control layers in my book. The last part was on the various ways to insulate the top of a house. The most common, of course, is to have…