Power Washing and Sealing a Deck

Sealers help keep your deck from turning gray.

If you have your deck cleaned and sealed by a professional, it will cost you $250 to $600, depending on your location and the size of the deck. For just a fraction of the cost, you can rent the equipment, clean and seal your deck over the course of one weekend.

Significance

Dirt and debris from foot traffic, drainage from flower pots, runoff from the roof and overflowing gutters can lead to mold and mildew on your deck. The sun also breaks down the surface of the wood, turning it gray. Snow and rain soaks into the wood, causing it to swell -- over time, the internal fibers will break down. With periodic washing and sealing, you can extend the life of your deck.

Considerations

Use a cold-water pressure washer when cleaning the deck. The hot water in a hot-water pressure washer is too damaging; it can raise the grain of the wood. Too much water force is also damaging. A washer rated at 1,200 to 1,500 PSI (pounds per square inch) is sufficient. The best nozzle to use sprays in a wide fan pattern. Use a 25- to 45-degree nozzle.

Sealer

Sealers with no tint may protect your deck from moisture, but they do not block out the UV rays of the sun. With no UV protection, the deck turns gray. Tinted oil-based sealers are the best choice. These sealers protect against the damaging effects of the sun. Sealers can be applied with a paint roller or a pump-type sprayer.

References

• Ultimate Washer: Deck Pressure Washing
• Bob Vila: Routine Deck Maintenance
• Real Estate Agents: Maintaining Your Wood Deck