NEVER SEAL YOUR DECK AGAIN - what does it mean?

In 2004 a number of companies came into the marketplace advertising "Never Seal Your Deck Again". It is important to understand what this means. It means you will never have to seal a deck again with a "sealer". It is important to understand what a sealer is; a sealer is designed to seal moisture out of the wood. What does a sealer not do; a sealer does not protect the wood from the Ultra Violet rays of the sun. Only a stain which has color pigment and is also a sealer will protect your wood from the sun and protect your wood from moisture.

If your deck is just sealed, will it turn grey? Yes, in as little as 6 weeks.
If your deck is stained, will it turn grey? No, not for a couple of years or more.

Keep in mind, a sealer is never a stain. A stain is always a sealer.

So, if you want your deck to turn grey, use a sealer or just let it weather. If you want your deck to have a colored appearance, then a sealer is unnecessary (and a waste of money) because what you really want is a stain. To have a color to the wood such as; cedar, redwood, honey, grey or any other color tone, the slogan should be "Regularly Stain Your Deck"

Now, let's talk about companies that advertise to "Never Seal Your Deck Again. These companies are using more or less the same type of product. It is a silicone based product. One such product is called Seal-It. It can be found at Seal-It is an honest silicone based sealer manufacturer that explains what their sealer does and what it doesn't do. From their website "SEAL-IT Wood Sealant creates a permanent, effective seal against moisture, acids, time and weather, while hardening, increasing density and strengthening new or existing wood." Seal-It Wood Sealant also states on their website "ONLY use on pressure treated wood that has been allowed to cure/dry for 3 to 6 months." Be sure to know what kind of wood you have on your deck or wood structure. Many decks are made of either cedar or redwood, not pressure treated pine.

It is important to understand that Seal-It Wood Sealant does not protect the wood from the UV rays of the sun. It is also important to remember that only the treated portions of the wood get the benefit of being sealed. Typically, the ends of the boards, between the board, and the underside of the boards do not receive protection.

So, if you want your pressure treated pine wood to have a grey appearance caused by the sun's UV rays, which you never have to seal again, then a silicone based sealer is one to consider. But remember, this does not mean the wood is now maintenance free. It still needs to be cleaned regularly. Normal dirt, debris, algae, moss, and UV degradation will cause the wood to lose its fresh and appealing appearance.

If what you want is for your wood to maintain a cedar, brown, redwood or any other color, then you would be interested in having a stain applied every 2 to 3 years to the horizontal surfaces and 4 to 5 years on the vertical surfaces. The deck should be washed using low pressure with proper cleaners and brighteners to remove the grime build up. Next the wood should have stain applied to seal it, protect it from UV rays, and to provide your color of choice. In this case, sealing your deck with a silicone based sealer would work opposite your goal and would be money wasted.

"Silicone sealers for masonry have been in common use since the 1960's.  If they were useful for wood, it stands to reason that the major coatings manufacturers would have made their own versions decades ago.  That none of them have, tells you it probably isn't a particularly useful idea.  I know of No Reliable source that recommends silicone sealers for wood." Ed Burke - Professional Lumberman, Member Joint Coatings-Forest Products Committee, USDA Forest Products Laboratory  and technical advisor to the Cedar Lumber industry. 

Written by Mike Hilborn
Executive Director of the Power Washers of North America
Approved Wood Restoration instructor for the PWNA
Committee Member of the Joint Coatings - Forest Products Committee
Host of the Roof-to-Deck Home Show
Founder of Roof-to-Deck Restoration