The A to Z’s of Keeping Your Deck Beautiful
The largest complaint I hear is that wood sealers do not last. What starts as a
labor of love soon turns to a monotonous yearly cycle of reapplying sealers. It not
only gets expensive, it gets old quickly. While the quality of the sealer is important,
the most important determining factor of a durable exterior wood finish is the wood
prep. A few invisible mold spores can wreck an otherwise beautiful finish. An
improper pH balance can hinder penetration and shorten the life of the finish. Well
meaning do-it-yourself enthusiasts and many wood restoration contractors break
out the pressure washer and blast away thinking this is proper prep. You can
easily end up with more problems like splintering wood and mold that still sits
below the surface.
How can you extend the life of an exterior wood finish? The key is in using the right
detergent. The products sold at the big home centers are nothing but bleach and
cheap soap. While they work kill the mold, they also impart an unnatural whitening
to the wood and destroy the lignin in the wood. Lignin is the natural glue that holds
wood fibers together. Over time these “cleaners” take years off the life of your wood
making it more susceptible to drying out, checking and cupping.
I believe only one chemical is capable of cleaning wood, taking
care of buried mold spores and remains mild enough to use on
a regular basis.. sodium percarbonate
Without a big chemistry lesson, sodium percarbonate is a powdered precursor to
hydrogen peroxide. It's pH is slightly alkaline. It is the active ingredient in OxyClean
though OxyClean is a poor wood cleaner because it is mostly made up of fillers.
Wolman also makes a decent sodium percarbonate cleaner.
After a percarbonate cleaning, the wood should be pH
balanced with an acid like oxalic or citric. PressurePros,
Inc makes a product called Restore-A-Deck that was
made especially for cleaning wood and restoring pH
balance. It is a kit that comes with both the sodium percarbonate cleaner and a
mild blend of the above mentioned acids.
Step One, start with your sodium percarbonate based cleaner. Mix it with warm
water, apply liberally with a pump-up sprayer, keep wet for twenty minutes and
rinse away with either a pressure washer or a garden hose. If you aren’t
comfortable using a pressure washer then you may achieve better results by
brushing the deck before you rinse it.
Step Two, bring the wood to pH balance. Cabots makes a product called Wood
Brightener that works fine. The Restore-A-Deck kit has the acidic brightener
Step Three, patience. The wood has to be below 15% moisture content. How do
you know when it is ready? Well, you need a moisture meter. Otherwise I would
say 3 full sunny days above 70 degrees is safe. If you must sand, don't overdue it
and don't go above 80 grit. You are not seeking a fine furniture finish.. in fact that is
the worst thing you can do as you can easily clog the wood pores hindering sealer
penetration . Also, check the forecast. Will it be dry for the next 24 hours?
Lock It In
Now that you have performed the right wood prep and your deck is sitting there
looking like it was just built, now what? I recommend you look for a semi
transparent, oil/alkyd based penetrating sealer. You will find good products at your
local paint store. To name a few there is Cabot’s, Sikkens SRD, Deckscapes and
Wolmans F&P. I recommend you stay away from the box stores when making a
purchase. Their products are inferior and do not hold up.
I am also not a fan of water borne sealers nor epoxy type sealers. Water borne
sealers do not have the oil that keeps the wood conditioned and moisture
resistant. Epoxy sealers may look like a good thing initially as they tout ridiculous
durability and finish life. I have seen these type of finishes peel and they are
impossible to remove. You may end up stuck with a deck that looks hideous or
have to spend the money to have it replaced.
Application: This is the fun part. I do not like rollers. They apply too thickly and they
leave marks. They leave all the gaps between the floorboards unfinished which
looks like crap. So that leaves brushing, using a lamb's wool staining pad or
applying by rag. I'm not going to tell you which one I recommend but guess what?
You get what you pay for, be it in sweat equity OR cash. I offer this hand rubbed
service to my customers and the results are noticeable.
Some final notes.. if you decide to use a clear because you like the look of the
unfinished wood. Fine. Enjoy it for the 4-6 months it will last. After that the wood will
be gray and you will have locked that color in requiring a full stripping with much
stronger chemicals to change it.
One year after you make the first application, I recommend another cleaning and a
second coat on the horizontal surfaces. This is what gives you the durability. If you
are picky about the way your deck looks as I am, this is the way you do it. No
shortcuts. I have all my customers on database and return every four months to
clean and check my work. I have decks I last stained three years ago that look
fantastic. This is a true labor of love for me, folks.
The A to Z’s of Keeping Your Deck Beautiful