With Spring finally arriving to Loudoun county and the temperatures slowly getting up into a comfortable mid 60s – low 70s range in the evenings, it is hard to resist the urge to step outside and onto your deck to fire up the grill.
And while the steaks are cooking, spreading that divine aroma that is sure to drive your neighbors into a fit of envy, you – sipping on your favorite beverage – can’t help but notice that ugly green stuff that seems to had appeared out of nowhere and now is spreading all over your deck: floors, hand rails, spindles. The mold.
Any mold is a living organism and it needs food to grow. It finds its food source from pollen and dirt that accumulates on your deck floors and railings, also from overflow from flower pots on your deck, gutters above it, etc.
So to effectively battle the mold you would need to remove its food source first: pollen, dust and dirt, and any debris from your deck, and of course wash away the mold itself.
In a case where mold is barely noticeable, or if you happen to catch it at its early stages of growth, you can use warm soapy water and a brush to wash it all off. Make sure to rinse everything off very thoroughly with a garden hose afterwards. Otherwise, after your deck dries up the residue that wasn’t rinsed off properly will form a biofilm which again will serve as a meal for mold.
For more stubborn areas where mold had been allowed to propagate for a longer period of time, a power washer can be used. Please, note that excessive pressure WILL damage the finish on your deck. So use the lowest pressure possible and keep the wand as far away from the surface as you can to achieve the desired results without causing irreversible damage to the deck material.
The most effective way to clean large areas of mold off of your deck surface is to use a combination of a power washer (set to a very low pressure – “Softwash”) and a commercial deck washing solution that can either be purchased from your local home improvement or hardware store, or you can mix it yourself. The latter will save you a lot of $$! The solution is very easy to prepare and contains only these three ingredients: water, detergent and sodium hypochlorite (commonly know as your household bleach).
Word of caution: not any detergent can be safely mixed with bleach! Please, read the labels and make sure you do not mix something that is not compatible with bleach. Certain detergents mixed with bleach will create harmful vapors that can be fatal. If you are not 100% sure it is safe to use, then please don’t. Instead, call a professional for advice.
Do not, however, be afraid of using sodium hypochlorite (bleach) based cleaning solution! Bleach is recommended by Trex composite wood decking material manufacturer, Vinyl Siding Institute and Asphalt Roofing Manufacturers Association as the best method to fight mold and mildew (sources provided below).
Once all the ingredients are mixed at proper ratios and the solution is prepared, apply it to the deck surface with a pump up sprayer and allow it to dwell for a couple minutes before gently rinsing it off with a low pressure power washer. Work in 100-200 square foot sections to avoid extended dwell times. You will be amazed with how clean your deck becomes and how little time and effort the whole cleaning process takes!
And now that your deck is clean and mold free again, it’s time to go check on your grill! I bet the steaks would taste twice as good now and your neighbors would envy you twice as much!
Author, Owner and Operator
Northside Power Washing
(703) 341 9971