Wow, a page dedicated to wood rot! I bet you’ll find this as exciting as me!
Most of us have gone through life just accepting wood rot, termite and other damage. It’s just part of owning a house, right?
Hopefully, you’ll see that most wood rot is totally avoidable. Yep, you got that right. You don’t have to put up with rot.
If you look at almost every place you find rot, you can trace the rot back to water. Wood installed in dirt. Wood in contract with contract near the ground. Unprotected wood forming ledges where rain sits and soaks in. Flashing installed improperly. Vapor barriers in the wrong place. Humid basements and crawlspaces. All these things can lead to rot and all are avoidable.
The key to avoiding rot is to respect moisture and understand basic physics and let things dry out. And by basic, I mean the type of physics you learn in grade school. You know, water runs down hill. Water can go uphill if it’s sucked into a sponge. Water evaporates under the right conditions but it sticks around in a terrarium. That’s about it. Understand these things and you’re better off than most builders. No joke.
Look at the picture above. What happened?
First, check out the trim board. I’m sure it was beautiful when the builder nailed it on and subsequently painted the wall, but if I had seen this being installed, I would have told the builder “that is guaranteed to rot out, and sooner than later.” If they didn’t throw me off the work site or hit me with a 2×4 for being a wise guy, they might have learned why.
First, notice that the rotten wood behind the trim wasn’t painted. Most wood acts like a sponge, especially when the end grain is exposed. The builder painted the wood after they nailed it on. That’s usually fatal. Most types of unprotected wood, installed near the ground, is guaranteed to rot. It’s not a tree – don’t plant it in the ground.
Second, remember your grade school physics. Water runs down hill. It will also seep into narrow spaces where it will sit until it is totally absorbed or it can evaporate. When it rained, that trim piece allowed water to seep between it an the unprotected wood of the wall. Worse, once the water got in there, surface tension and other forces would hold it in that crack, where it would slowly soak into the wood. Then it would rain again, and the water would soak in more. That wood never had a chance!
Third, as noted above, the wood is installed basically on the ground. What’s the ground? It’s a big sponge. It’s wet. It releases water continuously. Any time you have wood too near the ground, if it’s not protected wood, it will rot. Read that again. It will rot. I guarantee it. Wood should be kept at least 6″ from the ground. Probably more. With landscaping. Mulch, etc., that 6″ will shrink over time and before you know it, that wood will be sitting in a puddle. And then the termites or other critters will come. They love wet wood. And then you’re doomed.
The Rotten Hall of Shame
Just how bad can it be? One of my first jobs involved a beautiful stucco home with persistent moisture problems. At first, I was called in because the interior finish was peeling off the walls. I found the source of that moisture, but warning bells were blaring in my head because I observed improper flashing techniques and the house had a history of moisture problems.
I took the analysis to the next level and tested the moisture inside the walls and found high moisture in the walls all around the house! This was getting very uncomfortable. The builder and I discussed the problem and my conclusion was – the entire house was compromised and if not dealt with, it would be destroyed by moisture related issues.
I have to admit, I was afraid that the builder would start tearing off all the stucco and find no problems, but those fears were not realized. Instead, all over, he found scenes like shown in the photo above. Major structural members of the house were rotting away! This house literally could have self-destructed.