Recently a homeowner was inclined to wash and seal his own deck over a weekend. He rented a pressure washer and bought some deck cleaner. His plan was to wash the deck on Saturday and then seal it on Sunday. He got up early on Saturday and started in on washing the deck. He was not aware of it at the time but there was remnants of an old deck sealer on the wood that the previous homeowners had applied. It was very faint as it had faded over the years but none the less it was still in the wood pours. The deck cleaner he had bought at a big box store was basically just soap and was not going to remove any old sealer. Pressure did not remove any either. But regardless the man went on.
He noticed some scarring and furring on the wood when he had finished but just figured the new deck stain would cover it up. It was proud of what had took him eight hours or so and a lot of hard work. He got up Sunday and prepared to seal the wood. This took him even longer than the washing even with his wife helping him. He finished it up Monday morning after giving up the night before. But now the deck was finished, cleaned and sealed what a beautiful sight it was. The man bragged about the job he had done and all the money he had saved doing it himself.
Needless to say he was dumbfounded when nine months later the new deck sealer started to peel and flake. Within a year the deck looked like a complete wreck, the deck sealer had completely failed. The man blamed it on the deck sealer and tried calling them and complaining, they told him that he did not prep the deck correctly so the sealer was not warrantied. You see, because the old deck stain was not removed and the deck was not washed with contractor grade cleaners it was not ready to receive new sealer. But when the man applied sealer anyway he was sealing the deck own doom without knowing it.
Deck sealer needs to penetrate into the wood, that is how it works, it is not like paint that forms a film and sits on top of the wood. But this is exactly what it did when he applied it over an old sealer. The old sealer kept the new sealer from being able to penetrate the wood. It is not meant to adhere to old sealer so it failed prematurely. Now the man had to have the deck completely stripped and rewashed to remove two layer of old sealer and it ended up costing him twice as much as it would have had he hired a professional to begin with. A lesson hard learned.
