I’ve loved the look of log homes since I was a kid, and I always wanted to build one. And when I learned about cordwood construction a few years back, I knew a time would come when I would be stacking those logs up and admiring the beauty that this construction technique provides. Virginia is a hard place for alternative building techniques like straw bale and cordwood construction. We are in a mixed humid climate and natural building materials don’t always cooperate with materials that can swell or retain moisture. So it took a lot of planning and research to devise a construction method that I was comfortable with.
I found that VA cedar was a great wood to work with for this building technique. It is resistant to moisture damage and after three years, there has been very little swelling and contracting of the logs. And most folks around here just use cedar for fence posts. I find Virginia cedar to be an amazing resource for building projects in general. It doesn’t have high strength levels when used for lateral support, but its great for stacking cordwood walls or decorative rustic posts. So I am pleased with the look of this wood and its performance over time.
Because cordwood involves stacking firewood-sized logs with mortar in between, there is a high susceptability of mortar cracking- due to the large joints being filled. After much research, I ended up creating a custom mortar blend. I used masonry grade lime, portland cement, sand, and sawdust soaked overnight in water. Sounds crazy to add the sawdust, right? Well, the reason for using it involves the moisture that it slowly releases into the blend as it dries. When mortar dries slower, there is a less likelihood of cracking. And it worked because the structure is holding up just fine after several seasons of hot and cold weather (with the inherent shrinking and swelling of the wood set in this mortar blend).
Is cordwood for everyone? No, I don’t think so. It isn’t terribly energy efficient. Heat tends to migrate in the direction of the wood grain, so stacking logs in this fashion is less energy efficient than log home building. But anytime you’re building with logs there will be a sacrifice of energy efficiency for the aesthetic appeal. And in my case, this structure is only a garage, so I can live with that. Because it looks great and it should outlast most homes and with zero maintenance. Check out the pictures. My next blog will discuss the green roof that lives on top of the cordwood building. But that’s another story for another day…