Roman's guide, tips and instruction on how to power wash a wood deck.
While its always best to hire a professional deck cleaning company to get this done, many people will chose to do it themself. The following is some information about how we do it and how I sugest to get it done .
Now keep in mind that your electric pressure washer or small gas engine power washer most likely has more then the pressure required so you need to be carefull when it comes to wood deck cleaning as damage can be done quiet easily and the biggest problem of it is that when you power wash and your deck is wet then it almost always looks amazing until the next day when you see it dry and realize how much damage was done.
NEVER EVER START A POWER WASHER AIMING AT A PERSON, ANIMAL OR ANY DELICATE SURFACE AS NOT ONLY THE STREAM OF WATER CAN HURT SOMEONE OR CAUSE DAMAGE BUT THE NOZZLE CAN SOMETIMES DICONNECT AND SHOOT OUT LIKE A PROJECTIKE AND HURT SOMEONE OR CAUSE DAMAGE.
Following is a list of thing you need to decide before even starting the power washer
Decide on what type of cleaning does the wood deck need ?
Now there are many different cleaning detergents for wood deck cleaning and picking the one that meets your needs is quiet impoortant, a too gentle of a cleaner will not clean a really dirty deck yet you would not want to overdo it witha heave duty cleaner stripper if all you deck needs is a very light cleaning.
A gentle light cleaning of wood deck.
If you deck is fairly new or in great shape it might just need a light cleaning:
- - For regular pressure treated wood in great condition a light mixture of sodium chypochlorite / bleach at 1% with soap is often used for this type of wood and light cleaning, the mixed solution is applied via pump sprayer and lightly rinsed off using low pressure.
- - For hardwood decks like mahogany or ipe light cleaning, we usually mix raw chemicals for a custom mix but it would be similar to using ( oxyclean - sodium percarbonate at just a few oz per gallon) . Now remember when mixing oxy clean or other sodium percarbonate based cleaner mix with with warm water in an open container like a bucket and fill it no more then half full with warm water then add the powder to the warm water and mix for 10 minutes, after adding the powder and as you mix you will notice foaming up that raises and fill the bucket more and this is why you do not fill the bucket conpletly as not the have a spill. After a few minutes of mixing add the solution into a pump sprayer ( please remember that this solution is active for a few hours, any time you are not actively spraying you need to release pressure and open the pump sprayer or the pressure due to oxygen release will build up and the pump sprayer will explode) if your deck is not large you can spray a whole deck but if your deck is sizeable say over 100 square feet it is recomended to decide it into sections and do the cleaning 1 section at a time, Apply the cleaning solution to your section of the deck and let it soak and do its job - keep it wet by either misting with water or more cleaning solution - do not let it dry, give you cleaning solution time to do its job as in 10min minimum, when you cleaning solution has the time to do its job then the rinsing will be easier, faster and final clean deck will look better .
If you do not have the nozzles for low low pressure rinse then I wpuld sugest scrubing the deck gently with a soft deck brush going along the boards and rinsing with a garden hose, too much pressure and wrong techniques of Fannin can trully make the hardwood mahogany or ipe deck look really bad when it dries - see below more on how to use a power washer, tips nozzles and technique.
Medium to heavy duty cleaning of a wood deck.
- #1. While we mix raw chemicals ourself, we recommend you pick up a pre made specially wood deck cleaner for this due to safety concerns . Pick your wood deck cleaning detergent and please keep this in mind no matter how good the cleaner is if you don't give it time to work then it will not do its job and this will make you cleaning - rinsing - power washing job that much harder.
- #2. Mix you choice of deck cleaner according to the label direction, do not change the mixture by adding more as that can actually be counter productive .
- #3. Apply to the deck and give it time to work as mentioned on label which is likely 10min plus, now while you are giving it time to work please don't let it dry, keep it wet by misting it with water .
- #4. After the required dwell time proceed to power washing - rinsing of the deck ( see below on technique and tips)
- #5. When you are done power washing your deck you might need to neutralize, most deck cleaners will have a high ph and need to be neutralized with a deck brightner which is often oxalic acid or similar , thisbstep is almost always a must before applying any stain, this neutralizes you cleaning detergent, brings down the ph and helps you stain actually take / absorb better.
How to actually use the power washer to clean the wood deck.
- #1 - Most power washers with standard tips will will have way more pressure then its recomended for wood deck cleaning, we use and recomend getting oversized tips to decrease pressure while still getting the full water flow gps put of your machine, the more water flow the faster the cleaning. Depending on type of wood the desired pressure will vary but it's much better to start lower pressure and increase if need be, the lower the pressure the better it is for wood, we recommend and will use as low as 200psi but never more then 1000psi.
- #2 - Wood especially when wet is very easy to mark up and tear up so Never use pencil jet tips on wood, never use rotating turbo nozzle tips on wood, we use and recommend a wide patern fan style jet like 40° fan tip or even a 60° fan tip.
- #3 - Always go along the deck boards and never across.
- #4 - Use a fan out technique when wanding your deck - this means never do sudden stops and go back in opposite direction - fan it out at each end
- #5 - Do not stay still, keep the wand moving and keep fanning out, if a spot has to be hit again just fan out over it a few times.( video will lbe input here soon for better explanation of this technique)
Some questions you might have about wood cleaning and our practices etc.
Question- Why do we not buy or use pre made wood cleaners available in retail stores- are they not good ?
Answear - No that is not the case, there are many fantastic wood cleaners readily available, the only reason we buy in builk and use raw chemicals to make our deck cleaning solutions is because we clean many thousands of square feet of wooden decks a year and we have spent a significant amount of time on wood cleaning and restoration classes, courses, learning about said chemicals and testing the proper ratios to be able to custom mix what we belive is best for job at hand. For an average person cleaning their deck there would be no real cost saving due to quantity and the cost of it plus many require knowledge how to store as they are dangerous to store and they have a limited shelf life so buying to use over many years is not an option - some have a shelf life of only a few months.
What we recomend is buying from a local supplier a retail product amd enough for you project at hand .