Treated lumber is protected from many things, including mold and mildew but that only means it will not penetrate the surface quickly. Over a long period of time, if the mold is left on the treated lumber, it will eventually work its way into the grain of the wood. Depending on the wood and the treatment, this could take anywhere from weeks to years. The problem of mold on treated lumber is more about your protection than the wood as mold can make people ill. It is possible to clean mold off of treated lumber. The following article will share with you some tips and tricks on how to do it so you do not damage the wood.
Use a Soft Touch
When you see mold on wood your first reaction is often to just throw it away but that will cost more money to replace the treated lumber. Mold can easily be scrubbed off the surface of the wood but the trick is to not scrub it too hard. Using a wire brush to remove mold from treated lumber will ruin the surface of the wood as well as push the mold further into the grain. Avoid using a harsh brush like metal and instead use a nylon brush with soft bristles and scrub it lightly.
Removing mold is often done by using commercially purchased chemicals. These chemicals are not only damaging to the wood but also to humans and animals. The chemicals outright obliterate the mold and nearly everything else it comes in contact with. Completely ignore using any harsh chemicals on treated lumber. Go with something very simple, inexpensive and not at all dangerous: soap and water. Use oil-free dish detergent mixed with hot water. If the mold has been sitting on the treated lumber for a long period of time, then use a mixture of white distilled vinegar and water at a ratio of 2 to 1.
It's in the Motion
Scrubbing wood is like scrubbing any other material. If you scrub a stain along the grain (either toward or against) you'll do more harm than good. Scrubbing any stain with or against the grain will cause the stain or mold (in this case) to go even deeper into the grain. When you are scrubbing with soap and water always do so in a circular motion which will help pull up the mold instead of rubbing it in.
Once the treated lumber has been scrubbed you will be tempted to wipe off the soap but this can redistribute the mold to other areas of the treated lumber. Instead of wiping the soap away use a power washer to remove it instead or dump a bucket of hot water over the treated lumber.
Remove Pooling Water
When you remove mold with water there is a chance that water may pool on the wood or at the base of the wood. It is important that you soak up this water or more mold can form.