Up until now, concrete cracks have been the nemesis of the construction industry. In fact, there’s an old joke that there are two types of concrete. The first type is concrete that has cracked. The second type is concrete that hasn’t cracked…yet. But is there something new on the way?

Concrete “flatwork,” that is, concrete poured in slabs for floors, sidewalks, driveways, and roads, is particularly prone to cracking. It will shrink as it “cures” and crack. And it will continue to swell and shrink when it gets warmer or cooler and be susceptible to developing more cracks. (more…)

It’s freezing cold across much of the United States. Are you wearing passive solar clothes to stay warm?

I know it sounds like an odd question. We tend to think of using solar design for houses, not clothes. I’ll explain.

If you know it’s a cold day, do you think about what you’re going to wear? Of course you do. You might wear several layers. The layering forms more tiny air spaces around you and increases the insulating effectiveness of your clothing. You might pick out dark colors. Even if you don’t think of this as “passive solar dressing,” it is. dark colors absorb the radiant energy from the sun better than light colors. I’m sure when you’re outside on a cold, but sunny day, you walk on the sunny side of the street to stay warmer than you’d be on the shaded side. Ah! Passive solar principles, again. It’s nothing more than proper insulation and receiving the free energy benefit from the sun. (more…)