Blasting vs. Power Washing
Why Do We Cob and Sand Blast vs. Power Wash?
Sand or cob blasting has a number of advantages over power washing. The process of removing a finish from the logs is, simply put, a matter of throwing something at the building at a certain velocity (or pressure) that is sufficient enough to take off the finish while causing as little trauma as possible to the logs.
Blasting is a dry process. When dry, the surface of the finished logs is somewhat brittle. When the dry logs are hit with the sand or cob media, the brittle finish is quickly and efficiently removed leaving the logs relatively smooth.
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Blasting off a dark finish so that a lighter stain can be applied. |
Blasting works great to remove stain or paint on shakes too. |
Power washing is a wet process, which relies on water as the media to remove the finish instead of sand or cob. As water is applied to wood, it expands and more importantly, it softens the fibers of the wood. These soft fibers are then exposed to 1800 to 3000 psi of water. This process can cause the fibers to break length-wise and can result in what is referred to as the “fuzz effect”. This basically looks like the log home or cabin has a grown ½” long hairs.
Introducing more moisture to the wood is exactly the opposite of what log homes need because water is the enemy of a log building. See Why Do Logs Rot for more information.
Another disadvantage of power washing is that the high-pressure water used in the process makes its way into parts of the log building that have never seen moisture before. This can cause a number of additional problems including:
- The feces from rodents (bats, mice or rats) gets washed out onto the surface of the logs and can cause staining
- The insulation between the logs can get wet and cause mold and mildew to form
- The subsequent quick-drying of the outer log surface can cause additional checking (cracking) to occur in the logs, which can lead to further problems such as rot
While it is almost impossible to keep a log home from leaking inside to some degree when power
washing or blasting, the problem with power washing is again, the use of water. Not only are you wetting the logs (remember, water is the enemy of a log home) but this water can make its way into the home and stain or ruin interior finishes, floors and home furnishings. Check out the photo to the right. Here you can see that water leaked inside the building and caused major staining of the interor logs.
The sand and cob blasting material may come through the walls to some degree, but the dust is dry. Sometimes if the dust is significant, we will drape the interior walls with plastic in order to allow the
dust to fall to the floor as it comes inside. This minimizes the dust coming into the home and makes it easier to clean up with a vacuum or a broom.
For more information, refer to our sand and cob blasting procedures.
Contact us to inquire about having your log home or cabin sand or cob blasted.