Dave MacAusland
Should I Clean Before Sealing the Deck?
Updated: Jul 27
Do you have a deck? Do you want to protect it with sealant but are unsure if it needs to be cleaned before sealing the deck? If so, read on!

Cleaning before sealing always improves end result beauty. Where wood has been previously sealed, cleaning before re-sealing helps remove the remaining old sealer and opens the wood better so the new application penetrates deeper, looks better, works better, and lasts longer.
Sealing over prior sealer results in film buildup, usually not a good idea.
Without a good cleaning, sealing gray wood turns wood dark gray- not an aesthetically enhancing though the sealer will still perform these other important functions:
Keeping Water Out, resulting in less wet/dry, swell/shrink phases. This improves dimensional stability and reduces wood checking and cracking. Keep water out also keeps wood rot organisms from living in and eating your wood!
Keeping Wood Mold Free If a Biocide infused sealer is used, LIKE OUR SUN FROG SEALERS, less (or no) surface mildew will grow, thereby keeping wood from LOOKING GRAY VISUALLY (as mildew naturally grows on unprotected wood, it's appearance turns GRAY).
Result? For best results, clean your wood first (see our Deck Cleaner), and possibly brighten it too (see our Born Again product). When sealing is done after cleaning and brightening your wood will look great and last much longer! Protect and enjoy your investment!