Black mold - we have all seen wood sided homes that turned that death black color. It just looks bad.
In wooded or shaded areas mold is going to present itself insidiously. The problem is that for many years the only semi-transparent wood stains on the market were oil based.
Oil-based stains actually feed mold. They contain natural resins like linseed, vegetable, tung oils and animal fat which make a scrumptious dinner for mold spores.

Learn how to remediate mold on your wood siding - both removing mold and then preventing mold from returning.
How To Prevent Mold from Forming on Your Cedar Siding
As wood siding experts, we know that there are specific steps to take to maintain your wood siding long term. It starts with the type of stain selected and continues with monitoring your wood siding condition annually.
Let’s start with the factory finishing option. Factory finishing all four sides of your wood siding before installation - and sealing the ends during installation - continues to be the single best protective measure you can take towards long term wood siding and decking performance and the most economical way to achieve a multi sided finish.

Use a lower cost finish for multi-sided factory coating, such as Sherwin Williams WoodScapes, and then upgrade to a higher cost synthetic resin-based finish like DEFY Water Repellent Wood Stain for a 2nd coat during installation along with follow-up maintenance coats during the lifetime of your wood siding.
That way you are only paying for the good stuff (synthetic resin) on the face of the wood where it is needed to prevent mold.
If you have a heavily shaded area, we recommend a water-based stain as the technology seems to have improved to the point where they are equal to or greater than their oil-based contemporaries.
Consider using a water-based stain over an oil-based stain. There are newer water-based wood stain products on the market that have synthetic resins which block water but do not feed mold spores.
Also, minimize the amount of mulch you add around the perimeter of your house and wood siding, as this can also encourage mold growth on your wood siding.
The key is do not wait. If you start to notice discoloration, appearance, or evidence of mold, it’s time to clean your wood siding.
Don’t wait until your wood siding looks like this!

How To Clean Mold Off Cedar Siding
First things first, do not pressure wash your wood on a high pressure setting it can permanently damage your wood. Secondly, do not clean your wood mold with Chlorine Bleach, it will eat the fibers and discolor your wood siding.
Check the wood cleaner product label for the chemical name for chlorine bleach, sodium hypochlorite.
For more in depth instructions on how to clean your wood siding, read our guide on How to Clean Cedar Siding in Just 4 Steps.
- Clean your wood siding with water.
- Apply Oxygen Bleach.
- Apply Oxalic Acid.
- Re-stain your wood siding.

Just remember that 99% of all reported siding problems are installation and maintenance related. If you take care of your wood- it will take care of you. If you're interested on hearing a customer's experience with wood siding prevention and removal, visit our Buffalo Lumber Community page to read our case study and gain expert field advice on wood siding mold removal.