How much does it cost to pressure wash a deck?

Reviewed by Adam Graham remodeling expert. Written by Fixr.com.

Over time, mother nature takes a toll on the surface of a deck. It can quickly become stained and discolored. Deck pressure washing uses a strong stream of water to break away and remove dirt, grease, mold buildup, and grime from a deck to thoroughly clean the surface. It revitalizes the deck’s appearance and prepares it for possible staining or painting. Pressure washing increases the lifespan of your deck by removing bio-contaminants that can break down the wood’s fibers.

The average cost to pressure wash a deck ranges from $100 to $200 with the average homeowner spending around $145 to effectively pressure wash a 500 sq. ft. deck. At the low end of the spectrum, you might pay $87 to pressure wash a 300 sq.ft. deck, and at the high end you can pay up to $766 for hand brushing and pressure washing a 500-square-foot deck.

Price to Pressure Wash a Deck

Power Washing vs Pressure Washing

Many people use the terms power washing and pressure washing interchangeably, but they are different processes. Both rely on high-pressure water, but the power washing machine heats the water, while pressure washers do not heat the water. The cost to power wash a deck tends to be about the same as pressure washing.

Power washing is quick and effective. It also does not take a great deal of time to successfully clean even a heavily soiled deck. However, some surfaces simply cannot handle the water pressure and heat of power washing. Deteriorated wood might start to break up from the water’s onslaught. Typically, professional power washers use a detergent with the machine which can also adversely harm surrounding plant-life.

Pressure washing does not use heated water so some mold and mildew might not respond even with the use of chemicals to try to clean away the heavily soiled surface. Many surfaces such as fragile wood respond better to pressure washing since the cleaning method does not use hot water.

Deck Pressure Washing Price Per Square Foot

The price to pressure wash averages $0.30-$0.40 per sq.ft. When pressure washing your deck, you should have a professional carry out the task. The job involves using a high-pressure washer that creates a forceful jet of water combined with detergent. If care is not taken, it can easily damage the deck surface or surrounding landscape. Below is a table outlining the different deck sizes and the cost to pressure wash each one.

Pressure Washing Prices Per Hour

Professional pressure washers charge $50 to $150 per hour. Typically, they charge by the sq.ft., but they will charge by the hour occasionally. You can hire a professional pressure washer to quickly and thoroughly clean your deck. They will use the high-pressure water stream produced by the washer to quickly break down dirt, mildew, and grime from the deck’s surface. For heavily soiled areas, they might opt to put detergent in the machine and give the surface a light scrubbing. For a 500 sq.ft. deck, it will take about an hour to two hours to clean.

Price to Pressure Wash a Deck by Material

The cost of pressure washing ranges from $150 to $220, depending on the type of deck material. Pressure washing should always be undertaken by a professional because the powerful stream of water can damage some decking if not applied at the right pressure. This is especially true for wood decking. The average cost to pressure wash a deck varies depending on the decking material. Some decking materials such as wood and composite require greater time and care than aluminum. The costs in the table are for a 500 sq.ft. deck.

Pressure Washing an Aluminum Deck

The cost to pressure wash an aluminum deck averages $150 to $180. Power washing easily restores the appearance of an aluminum deck. It lifts away dirt and mildew with ease, especially when used in combination with a detergent. Also, aluminum decking stands up well to high pressure without sustaining damage. Since aluminum decking can handle hard cleaning, it takes less time because you can scrub the surface and hit it with a heavy stream of water. With less time required, it tends to cost less to clean.

Before pressure washing the aluminum deck, apply a deck cleaner to break up the debris. To apply the cleaner, you can use the soap dispensing nozzle of the pressure washer to effectively spread the cleaner across the deck's surface. Scrub the soapy cleaner on the deck's surface using a stiff bristle brush to loosen the hard-to-clean areas. Use the widest spray nozzle on the pressure washer to spray away the soap and debris from the deck’s surface.

Pressure Washing a Wood Deck

The average cost to pressure wash a wood deck is $180 to $200, including labor and cleaning materials. Wood decking has a very porous surface, which can easily be peeled away or damaged by a powerful blast of water. Wood decking is often painted or stained, which can easily start to peel away. In some instances, pressure washing is used to remove all paint before applying a new coat. Please remember, wood decking that undergoes pressure washing is very susceptible to damage if the job is not carried out properly.

When pressure washing a deck, the pressure washer operator should always operate the washer at the lowest possible pressure setting using only 1,500 pounds per square inch (PSI). If the deck is heavily soiled, scrubbing the surface to break up the debris before pressure washing renders the best results. Always use a synthetic brush to scrub the spots that are not coming clean with the pressure washer to create a pristine surface.

Composite Deck Pressure Washing

The average cost to pressure wash a composite deck averages $200 to $220. Typically, composite decking stands up to the elements well and responds nicely to pressure washing. However, it cannot handle sustained high pressure. Always pressure wash composite decking at low pressure--use 1,500 pounds per square inch (PSI). The cost to power wash a composite deck tends to be on the high end due to the time involved in safely carrying out the cleaning. Composite decking is the most expensive of all decking materials to pressure wash because it requires light scrubbing throughout and a low-pressure water stream to clean the surface gently.

Always check the composite deck’s warranty before pressure washing the surface because some warranties are nullified if pressure washing is used. When pressure washing the deck, use a fan tip and hold it at least 8 inches from the decking material. If there are stains or built-up debris on the deck’s surface, scrub the areas using a soft bristle brush. After power washing, allow the decking to air dry.

Cost to Pressure Wash a Deck

Professional pressure washers will charge from $0.30-$0.40 per square foot depending on the amount of soiling, mold, or mildew on the deck. The price per sq.ft. includes materials. Some professional pressure washers also charge $50-$150 per hour and about $50 for detergent. A 500 sq.ft. deck will cost from $100 - $200 to clean depending on the degree of dirt, deck material, and time involved to clean the surface. The average price for a moderately stained deck is $145, being the 75% of the cost labor and the rest materials

You can hire a professional pressure washer to quickly and thoroughly clean your deck. They will use the high pressure water stream produced by the washer to quickly break away dirt, mildew, and grime from the deck’s surface. For heavily soiled areas, they might opt to put detergent in the machine and give the surface a light scrubbing. For a 500 sq.ft. deck, it will take about an hour to two hours to clean.

There are many factors involved in calculating how much it will cost to pressure wash a deck. The size of the deck is the main factor, considering that most professional pressure washers charge by the square foot. Additionally, whether the deck is heavily or lightly soiled matters because the pressure washer might need to spend extra time cleaning the deck and applying additional detergents. The condition of the deck also makes a difference because decks that are decaying or heavily mildewed will cost more since they take extra time to effectively clean. Please note that if the decking material requires repairs then the final cost will increase, depending on the repairs needed. Typically, prep work is an additional fee when pressure washing a deck. If you want them to remove the deck furnishings and clear away debris then there will be an added cost.

Cost to Pressure Wash and Stain a Deck

The cost to pressure wash and stain a deck made of wood that measures 500 sq.ft. averages about $145 for the pressure washing and an additional $1,750 to stain the deck. The total average price to pressure wash and stain a deck is about $1,895. Some pressure washing companies will also stain the deck. However, in most cases, a painting contractor will pressure wash the deck before staining the surface.

Do You Have To Pressure Wash A Deck Before Staining?

If you plan to have your deck stained, you must have the decking material pressure washed before staining. Staining a deck is similar to painting. The stain, once applied, will show every imperfection. You do not want to spread stain over dirt and debris, or it will not evenly color the decking. The stain will flake away and fail to sink into the wood’s fibers to offer sufficient protection to the deck material. A deck that is dirty or has debris stuck to it will not stain well and will not look good when complete if you do not first pressure wash the deck’s surface.

Deck Pressure Washing Hazards

Pressure washers are powered by either a gas or electric motor. They consist of a motor, pump, and a highly concentrated nozzle that increases the water’s pressure by 30 to 80 times as it leaves the house. Most pressure washers easily generate from 1,500 to 4,000 psi. The spray can be extremely hazardous to human skin because it can quickly cause bruises and lacerations.

Deck Pressure Washing Damage

The powerful burst of water from the pressure washer can leave grooves in wood and composite decking if you use a pressure that is too high. Composite decking will actually start to chip under the water’s onslaught. Wood pieces can also break away and, in extreme cases, the boards can even start to crack. Areas of the wood that have already started to split from age and use will become worse as the water divides the broken area further. If the psi is set too high then the water stream can damage wood and composite material by chipping and peeling the surface. If the decking is painted and the psi is too high then the water will peel away the painted surface of the deck.

Enhancement and Improvement Costs

Deck Repair

The cost to repair a deck averages around $700 for labor and materials to replace five to six damaged boards. The cost of labor and materials to replace missing nails, screws, and other hardware on a deck averages $150. Before pressure washing your deck, you might want to explore deck repair costs if the deck is in poor shape. Some small repairs you might be able to complete yourself to save on the added price of labor and materials.

Deck Pergola

If you want to build a deck pergola before pressure washing the deck, then the average cost of a pergola is $3,500 when constructed from cedar wood that measures 10 ft. A pergola is a nice addition to any deck. It provides shade and protection from the sun’s harmful UV rays, which can rapidly break down decking material as the years pass. The pergola creates a nice, shaded area to sit on the deck. Some people use a pergola to support plants, such as vines or hanging plant baskets to add visual interest to the deck area.

Deck Sealing

The average cost to seal a deck that measures 300 sq.ft. averages $450. Sealing a deck protects the wood from both UV exposure and water. The chemical composition of the sealant makes water bead up on the deck’s surface instead of penetrating the wood, so it offers optimum protection from decay. Many people opt to seal their deck annually after pressure washing. The pressure washing removes the dirt and debris so a fresh coat of sealant can be applied to the deck’s surface.

Additional Considerations and Costs

• Maintenance. Maintain your deck by pressure washing it annually to remove any stains, mold, or mildew. Pressure washing once a year helps your deck last longer while maintaining its appearance. Typically, pressure washing should be performed in the spring.
• DIY. You can rent or invest in a pressure washer and undertake the task yourself. However, great care should always be taken not to use too high of a water pressure setting, or you could damage the deck’s surface. Also, always take great care when operating a pressure washer because you can bruise or lacerate your skin.
• Hire a Pressure Washer. If you want to hire a pressure washer, you should always get at least three to five estimates to determine the average cost and find out who is offering the most for the money. Ideally, you should go with the estimate that provides an affordable average cost.
• Insurance. Insurance is added protection. Choosing a company that carries commercial and general liability protects against potential damages that might occur to your deck due to pressure washing.
• Obtain References. Always ask the pressure washing contractor that you want to hire for past references and search for reviews online to make sure that they provide quality work.
• Electrical Requirements. Some decks have electrical outlets. You should always talk with the contractor about potential electrical needs. Always make sure the contractor is aware of where the outlets are throughout the home and around the deck. Electric power washers require an outdoor ground-fault circuit interrupter (GFCI) socket to operate safely.
• Gas or Electric Pressure Washer Considerations. Some companies have gas pressure washers. Others have electric pressure washers. You will want to find out if you might be responsible for the electricity used by the electric pressure washer. Some pressure washing contractors charge less to use electric pressure washers, so the cost evens out with a gas pressure washer.
• Wastewater Permits. In some states, wastewater permits are required when you pressure wash a deck. The contractor should always acquire all necessary permits for your municipality before undertaking the pressure washing job.
• Occupational License and EPA Guidelines. In some states, an occupational license is required for all contractors who work using a pressure washer. Also, all EPA guidelines should be followed to avoid potential fines.