Cedar Deck Maintenance: How To Pressure Wash A Cedar Deck

 Summer’s a comin’ around the mountain as she comes.

Have you been putting off your cedar deck maintenance?

Got some mold and mildew buildup?

It’s alright, it happens to the best of us. Especially if your deck faces North. We’ve already taught you how to protect your deck in the winter, so now stop being lazy and let’s learn how to pressure wash a cedar deck and get it ready for your next BBQ!

Those Leaves Are Killing You!

A quick word of caution before we get going. Old, wet leaves left on the surface of your cedar deck are the biggest cause of damage and dirtiness.

They will get down in the cracks between the boards and accelerate decay.

It’s good practice to try to sweep your deck at least once a week to keep the leaves from building up. A couple of minutes a week can add a couple of years to your deck’s life.

Materials:

  1. Power washer with 25 and 45 degree tips
  2. Deck stripper (sodium hydroxide based)
  3. Deck Brightener
  4. Sealant

Decks have a hard life sitting out exposed to the elements year-round . It’s no wonder that they need a little TLC from time to time. Doing it yourself can take you from $500-1000 for a professional cleaning to less than $200 to do it yourself.

I know which method I would choose.

I’m going to assume in this tutorial that you haven’t done anything to your deck in a while and it’s accumulated so nasty stains. We’re going to take it from zero to hero!

I’ll make note of unnecessary steps for those of you that just want a basic cleaning.

But First…

Power Washing Your Cedar Deck

Note: RealCedar.com advises against power washing your cedar deck because it can strip the softwood. Like most things, though,  this advice is dependent on your situation. Many people still choose pressure wash their cedar decks, and therefore we are giving instructions to those who choose to do so. We’ve tried to give instructions the best we can on how to safeguard against any consequences of power washing, but remember: with great power (washing) comes great responsibility.

Rent a Pressure Washer

Ok, first you want to rent your power washer if you don’t already have one. You can get one locally at Home Depot or, if you like to shop locally, you can try Arapahoe Rentals in Littleton.

You want to get pressure washer that allows for the use of chemical cleaners. They should have one. You also want one that can reach 1200psi, which isn’t too high, but any higher and you will start to strip wood. This is one reason some don’t like to power wash their decks.

Plenty of people do, though, without a problem.  

You can get a power washer for about $40/day.

Get Your Chemicals

  • Deck stripper: This part is for those that have let their deck go and have old stainer or bad stains that they want to remove. You use a deck stripper when you have some tough build-up to remove. Check to see if yours is pre-mixed or needs to be diluted.  
  • If this is a lighter job then you can just get a basic eco-friendly deck cleaner.
  • Deck brightener: Once again, this is for those out there that want to do a thorough job and restore their cedar deck to like new quality. Deck brightener will give the wood its original shine back before staining.
  • Cedar Sealant and Stain: this transparent sealer and light stain will darken your newly brightened cedar deck boards to a beautiful, natural color. A transparent sealant with no stain will protect the wood but allow it to turn that rustic silvery grey. Or choose a darker stain that you like.

 

Take Precaution

While many deck strippers are not harmful to plants, some are. It’s probably a good idea either way to heavily water your surrounding plants and grass and throw something over the nearest plants that might get hit by spray.  Also wet any siding that may get hit by offspray.

Down to Business

You’ve got your deck stripper loaded up, the power washer connected, goggles on and you’re ready to go.  

bubble from trailer park boys

Put the 25-30 degree tip (which at the right distance will be about the width of a deck board) on the wand and set the washer to 750-800 psi to start and turn it up no higher than 1000 psi if you think you need more pressure. It’s best to start with the stairs, if you have any, in order to get accustomed to the power washer and adjust your pressure and distance accordingly. It’s much easier to change a 2 ft. stair board than a 16 ft. deck board. Once you feel comfortable, move on to the railings and bannisters and work your way down to the deck boards.

Keep the wand about 10 inches away from the wood and try to keep steady momentum. Hovering over the same spot for too long will leave you with streaks that will have to be sanded out. Try not to turn up the pressure to obliterate hard stains, just go over them a few times. Any that don’t come out can be scrubbed away later with a brush and cleaner.

After the railings and banisters, move to the deck boards. This is the fun part where you really get to see the fruits of your labor wash away the grime.

You can use a feathering technique, which will help prevent streaks, for the deck boards.

“Feathering”is a technique that may help you mask the starts and stops of the sweep. With this technique you want to overlap the areas previously swept, making sure that the point where the nozzle is closest to the wood begins at the point where the sweep ended on the previous stroke. Always working with the grain or the length of the board, this technique requires more strokes and is slower but does an exceptional job. It also ensures that as much of the cleaner is removed/diluted as possible. Excess cleaner left on the deck surface can have long lasting and detrimental effects. Feather is the most efficient method for using a pressure washer on a deck surface.”

http://www.decks.com/how-to/14/using-a-pressure-washer-to-clean-a-deck

Give your deck a rinse with pure water when youre done to dillute the stripper a bit and wash any that might have hit your siding.

Brighten Your Cedar Deck

Now switch to the deck brightener and put the 40-45 degree tip on the wand and change the pressure to 1000 psi. Power wash your cedar deck like you did with the deck stripper, starting with the railings and bannisters first.

Deck brightener doesn’t need to be washed away after, but you should rinse your siding again. The brightener only takes a matter of minutes to work, and you should see some dramatic changes in your cedar or redwood now.

Give It A Once Over

Now’s a good time to give the deck a once over to look for protruding nails or screws that need to be replaced. We like using powder-coated screws on our natural wood projects because they won’t rust and bleed onto the wood.

This is also a good time for you to replace any boards that need to be replaced. That’s when you come to see us and pick up some kiln-dried cedar decking (wink wink).

Staining Your Cedar Deck

You should always wait 48 hours to let your deck fully dry. If it rains in that time then you have to wait another 2 days before doing it. You don’t want to stain in full sun, so try to do it in the golden hours of the morning or evening.  

Using a stain application pad will make life easier for you. Connect it to a broom handle and save yourself some back pain.

a man staining his cedar deck with a pad applicator

As usual, start with the railings and bannisters. Try to apply the sealer/stain with a steady motion and remember that the stain will darken if you repeatedly go over the same area. Smooth out any drops that fall to the deck to prevent spotting.

Move to the deck boards next and try to complete a whole board in one sweep. Having to start and stop will leave obvious areas of overlap. You want to soak the pad, but not to the point of dripping.

When you completed the deck boards grab a brush and do the hard to reach places and any touch up that you need. Be strategic about this because you don’t want to walk on the new stain for about 48 hours.

Conclusion

Grab yourself a beer and bask in the compliments from your wife or husband. You showed that deck who’s boss and it looks awesome again! Also, be content that you won’t have to do that again for a long time. And by then you can probably get your grandkids or children to do it.

We hope this was useful, and always encourage you to share it if you liked it and to give us a call with any questions that you might have.