DIY projectsHome Improvement

How to power-wash and seal your deck

Early Summer will bring with it a whole list of ideas for home improvement projects. Choosing which tasks to tackle can be challenging, which is why we like to suggest improvements you can easily accomplish on your own. This week’s idea is a fun one for warm weather…

How to power-wash & seal your deck…

A wood deck can be cleaned very well by power washing it correctly, but this can also ruin a deck if it’s not washed with the right technique. What power-washing should do is remove the grey surface layer to allow the natural wood colors to become visible again. This then will also will prepare the surface for finishing or sealing. If not washed correctly, the result could be irreparable cuts and damage, which can be costly to repair.

First, how to set up your power washer…

Power washers can be purchased or rented and will be either electric or gasoline powered. Check your local improvement locations for prices and rates. Either way, for most power-washers the pump will pressurize water at 1500 psi.

[1] Take your washer to a location around your home that is easily accessible for your deck and/or power source.

[2] Attach the garden hose and run COLD water through it before starting the engine. DO NOT USE HOT WATER, this will raise and expand the natural grains of the wood and cause damages.

[3] Use a moderate spray angle like 30 or 40 degrees. Do not use a focused tip as this could result in too much pressure in one focused area and damage the wood.

Next, here are tips for your washing technique…

[1] Keep the tip 4 to 8 inches from the wood

[2] Move continuously and don’t focus the sprayer on only one area

[3] Notice the wood change color as you wash it.

[4] Adjust your distance and speed accordingly to get the result you want

[5] Move the tip parallel to the grain to avoid cross-grain streaking

Next, here’s how to choose your sealer…

Finding the right sealer usually depends on how much sun your deck receives or if you live in an area that has higher moisture content such as a shaded forest.

If your deck gets allot of direct sun and is dry and grey, then you can use a UV-blocking pigmented stain.

If your deck is in the shade, protecting it from moisture may be more important. In this case you can use a water-proofing sealer. This also will show the natural color of the wood.

Most sealers a simple mixture of paraffin wax that is dissolved in a solvent. Re-applying the sealer annually is necessary for many sealers. Oil based preservatives are also available. These will provide longer protection and harden the grain but will cost more and may require different equipment for application.

Finally, here’s how to apply the sealer…

One coat is usually enough but it may require two if the deck is very dry.

[1] Wait 48 hours for the deck to dry after it’s washed

[2] Apply with a paintbrush, roller or sprayer.

[3] For brushing, a regular paint brush will take the most time.

[4] With a roller, use a medium to thick nap and attach it to an extension pole.

[5] If you opt for spraying, waterproofing sealers are thin enough for a garden sprayer.

[6] For oil or UV pigmented stains, you’ll need to use an airless or compressed-air sprayer.

Have fun and remember to always follow the instructions when using equipment, solvents and other improvement materials.

Leave a Reply