Do You Have To Pressure Wash A House Before Painting?

Do You Have To Pressure Wash A House Before Painting?

Is it necessary to power wash your house first? There are some good reasons why pressure washing is a good idea before house painting.

When you pressure wash, it creates a clean surface on which to paint. While you can paint a house without pressure washing first, you will find that the new paint adheres better to a clean surface, which results in a longer-lasting paint job. If you paint without cleaning the surface first, it will last 3-4 years. However, cleaning first will help your house painting to last seven years or more. This is because the paint will bond better to a clean surface, and it will be more resistant to weather, wetness, and heat. Looking for the best home painting company? Look no further! Hitch Property Constructions has you covered.

When power washing, you will want to rinse from the top down first, with clean water, to knock down large bits of trash or dirt and spider webs or other debris. After that, you will want to add the solution to the washer and clean – again from the top down – with the chemicals, followed by another clean water rinse. This will take care of nearly all of the dirt and debris and even some of the loose paint. You will still need to scrape as usual, since it will not take care of all old paint, but there will be less to do.

There are costs involved in pressure washing. You will need to rent a power washer. Since usually one uses a power washer only occasionally – once every few years – it makes more sense to rent than to buy. However, using a pressure washer to clean the house first will save money in the long run by making the paint job last longer. You can choose between a gas-powered or electric-powered machine. While electric should be sufficient for single-story homes in nearly every case, a two-story house would be better served by the more powerful gas-powered power washer, as it can reach the top with enough pressure to get it clean.

The cleaning solution will also cost some. Be sure to choose one that is made for pressure washing, and that is made for houses. You should not ever use bleach in a pressure washer, because it could damage it.

You may have heard that there are dangers to pressure washing. This is true, but they are easily avoided. Etching, which is small cuts made into the side of the house due to the powerful water, can be avoided by standing a little farther away (2 feet to 2 yards, depending on the strength of the spray). The other is an injection, or water getting under the siding or through seals, which often cannot hold up to the pressure. This can be avoided by paying attention to the angle at which you are holding the sprayer.

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Different Areas Take Longer To Dry

Depending on where you are in the country, different areas such as Denver, Phoenix, Dallas, Los Angeles, San Fransisco, Portland, Seattle, Boston, Chicago, New York City all have different humidity factors which determine how long you need to wait after pressure washing, letting substrate dry.

If unsure, a good way to figure out if the surface is dry is to take a small piece of plastic cellophane placing over a surface in question, taping all four edges to the surface, waiting a day. Coming back, if no moisture has built up underneath plastic sheathing, you’re pretty safe knowing exterior surfaces have dried back out.

Once properly dried, you can proceed with steps preparing to paint home’s exterior.

I know this may be a lot to ask, but it’s not everyday your home gets a brand new exterior paint job. As a matter of fact, today, some of the best exterior paints will last a lifetime if all proper steps have been followed.

But getting back to pressure washing before painting your home’s exterior, many advantages lay camouflage, with all impending work at hand. Here are some good thoughts to think about if you rent a pressure washer, getting the biggest use out of your daily rental fee.

Just remember, you’re not trying to peel paint, only lightly rinse off dirt, cobwebs, wasp nests, and any foreign matter. Even if you can’t see it, does not mean it’s not there. Once you start rinsing exterior off, you’ll see what I’m talking about.

Cleaning Gutters

Working from top to bottom, this is a great time to clean out those gutters also. Knowing this can be quite a mess, but having a pressure washer at your disposal, you can quickly clean exterior, having cleaned gutters at the same time.

After you’ve cleaned gutters, and have painted your exterior, gutters will drain properly, not harming your valuable exterior painting efforts either.

Best Pressure Washing Soffits

After cleaning gutters, coming down, great to rinse off soffits where many bugs make a nest, I’ve even seen hornets having a very large nest, also cliff swallows, barn swallows and the black-billed magpie build nests under soffit areas.

You may time washing after the young has flown the coup. But who cares about hornets, unless you don’t want to get stung. A way around this is wearing a painter’s Tyvek suit and a bee vale. Nevertheless, those critters have to go before painting, and pressure washing is the key, allowing you to apply the best paint for soffits.

Cleaning Exterior Walls

Coming down from gutters, fascia, also soffits, it’s time to rinse, cleaning exterior walls. Starting from one corner, working across, hitting every square inch. You’ll see all the dirt, and grim coming off, to your amazement. An almost invisible layer of grim, until you help it with a high-pressure wash. Knowing this is clean as a whistle, before doing anything else.

Pay attention to bottom edges of siding, also any nails that may be sunken in. This is where moisture can penetrate, further damaging. If the siding has swelled out too much, pressure washing can damage it beyond repair. So, when cleaning siding walls, pay very close attention.

Prepare Exterior Windows For Painting 

Not only pressure washing gutters, siding, & trim, but removing window screens, is a great time cleaning those cracks and crevices where windows slide up & down. No telling how many critters make a home there, getting rinsed away.

Never wanting to use pressure washer too close, can easily blow out screens, as well as harming the wood. Would recommend standing away, keeping spray tip at least 3-4′ away. Suppose using Red single stream tip, back even further. Preparing any wood windows for painting, this is the first step you need to take.

Pressure Wash Before Scraping

Always best to pressure wash before scraping is done. This allows everything to dry properly if any scraping is needed. Dried paint is much easier to scrape than wet gummy type. However, pressure washing will give you a good clue where you need to concentrate your scraping efforts a few days later around eves, trim, windows, & bottom of door areas.

You do not need to scrape all paint off before painting exterior, only where paint has failed. Pressure washing first will also help remove a lot of that dust & grim away before picking up a paint scraper. Don’t know about you, but I like working in an as clean environment as possible.

You can see much better any cracking, chipping, peeling, blistering, or bubbling which needs to be removed after the washing process has been completed. But again, not trying to wash off failed paint, as you’ll do more damage to wood, than manually hand scraping once dried.

Remembering after pressure washing is done, completely dried out, you need to apply a good bonding exterior primer on any bare wood surfaces. This ensures you premium paint will adhere properly.

How to Pressure Wash Your House Before Painting

For a new exterior paint application to succeed, the siding must be very well cleaned—a job that can be pretty laborious if done by hand-scrubbing. A pressure washer offers a quick and easy way to get the job done, but it can be tricky to use on the siding. If you aren’t careful, the high water pressure makes it fairly easy to damage the siding or even cause water damage to the sheathing and wall cavities beneath the siding. Check out Hitch Property Constructions for a huge range of melbourne home painter services. 

Hand-Washing vs. Pressure Washing

There are certainly advantages to cleaning your house by hand prior to painting if you have the time and energy. If you’ve ever taken your car through a touchless car wash, you know that washing without physical contact produces adequate, but never great, results. After a touchless wash, a white cloth wiped across the car may well still pick up dirt.

The same holds true of washing your house’s siding before painting—the very best results will be achieved by hand-washing with soap, water, and brushes. But realistically, it is very difficult and time-consuming to wash an entire house by hand, and a pressure washer can do an adequate job in a manner that is much, much easier.


The point of pressure washing your house siding prior to painting is to wash it, not to strip the paint. True, most pressure washers are powerful enough to take off paint, but for best results, stripping should be a separate step done with a scraper, sander, or heat gun after the process of washing.

Besides the dangers, pressure washing simply isn’t the most effective way to strip paint. In order to remove the paint by pressure-spraying, you need to inundate the base surface with massive amounts of water, which is never a good idea, especially with wood siding.

Pressure washing siding sometimes gets a bad name because of two dangers:

  • Etching: Under certain conditions, pressure washers can cut into concrete and brick, so imagine the potential effect on cedar, vinyl, or even fibre-cement siding. This inadvertent etching is easy to avoid, though, if you simply stand well back when aiming your sprayer at the siding. Depending on your washer’s PSI rating, this might mean anywhere from 18 inches to 6 feet away, minimum. Second, use a fan-spray nozzle, not a stream nozzle, which has a needle-sharp spray that can rip lines into the siding.
  • Injecting: Be careful of spraying at low angles under the siding. The high pressure can drive water upwards between the siding boards and soak the sheathing and/or insulation of the wall interior. To prevent this, never spray at an upward angle to the siding—only perpendicular or slightly downward. Watch out for other openings, such as heating exhaust vents, air vents in the attic or crawlspace, and cracks around windows and doors.

Types of Pressure Washers

Pressure washers come in both gas- and electric-powered models. Since you want to treat your siding gently, you won’t need a high-powered gas washer; an electric one will suffice. A washer with a PSI rating of 1000 to 1500 is usually quite sufficient for washing siding. If you have a two-story house, a high-volume gas pressure washer fitted with a special nozzle will allow you to clean the upper areas while standing on solid ground.

Make sure to use a cleaning solution made for siding, and avoid those that have bleach, which can damage the spray washer and kill plants.


Protect Landscape Plantings and Utilities

Where foundation shrubs or other plants are blocking the siding, protect them with sheets of plastic to prevent the pressure sprayer from stripping leaves off the plants. Damage to shrubs will rarely kill the plant, but it can disfigure it for the current growing season.

Also, cover air conditioner compressors and other electrical utilities with sheets of plastic before pressure washing the siding.

Spray Off the Major Debris

Using the pressure sprayer, rinse the siding with plain water (no cleaning solution), working from the top down. For this step, a wide spray angle and relatively low pressure should do the trick. Your goal is to knock down most of the visible debris: insect nests, leaves, and the majority of the dirt. Let the siding dry. 

Apply Bleach Solution to Mildew Areas

If your siding has areas that are discoloured with mildew, mix up a batch consisting of one part bleach to 10 parts water, and sponge the solution onto these areas. A garden sprayer can also be used to apply the bleach solution. Be careful to avoid spilling bleach solution on shrubs and other landscape plants. No scrubbing is necessary; the bleach alone will kill the mildew. At Hitch Property Constructions, we offer Melbourne home painting services.

Spray With Cleaning Solution

Complete this step when the siding is not in direct sunlight and when winds are calm.

Fill up your pressure washer’s tank with cleaning solution, then spray the siding with the water-solution mixture, working from the bottom up. Use a low pressure and wide sprayer angle while applying the cleaning solution. Your pressure washer’s instructions will indicate the proper settings for applying the cleaning solution.

Make horizontal passes along the siding, gradually moving upward but consistently using a slightly downward angle when spraying. A stepladder may assist here; move up a step or two with each pass so that you can continue pointing downward at the siding.


Let the solution work for about 10 minutes, then rinse with fresh water from the top down. While cleaning should always be done from the bottom up, rinsing should be done from the top down to prevent dirty water from running over the clean areas.

Rinsing usually calls for a more powerful pressure setting and wide spray pattern, but again, make sure to follow the manufacturer’s recommendations for the type of siding you have. Make sure to rinse thoroughly; this is where the major cleaning is done. To avoid damage, start rinsing with the nozzle held a fair distance from the siding, and gradually move closer back up again if you see any kind of damage occurring to the siding.

Let everything dry for 48 hours before painting or until any bare wood is 100 per cent dry. If a couple of weeks pass before you can get to painting, an additional spray-down with fresh water is a good idea. It’s surprising how fast spiders can move in, and dust can settle after cleaning.

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