Cost to Seal or Waterproof a Deck [2024 Data]

Sealing a Deck Cost Factors

Deck sealing costs can vary depending on your situation. You’ll pay less for a small deck off the kitchen than you will for a large deck surrounding a pool.

Most of the cost comes down to the amount of sealant you need and labor.

Size

The cost to seal a deck is around $0.75 to $4 per square foot for the sealant, application materials, and professional labor. If you plan to DIY, you can expect to spend about $0.25 to $1 per square foot in material costs.

Sealant Type

Sealant costs about $25 to $60 per gallon, and most decks need about two gallons’ worth of sealant to get the job done. The cost may vary slightly by brand, but it can also depend on the sealant type. Homeowners can choose between oil and water-based sealants, or they can find stain/sealant hybrid products that will seal and stain the deck all at once. Water-based sealants tend to cost a bit more than oil-based ones, while hybrid products will usually cost the most.

Materials

Sealing a deck costs about $0.25 to $1 per square foot for the materials. You’ll need at least a couple of gallons of sealant, plus brushes, rollers, or sprayers, to apply the sealant. Before getting started, you may also need to strip any old coatings by sandblasting the deck. You should also clean the deck and let it dry before starting, which will add to the cost of tools and materials if you don’t have these items handy.

Labor

Professional deck sealing costs about $0.50 to $3 per square foot in labor, or around $40 per hour. Labor makes up about half to 75% of the project cost, but the pros will be able to apply even coatings more quickly and efficiently than you can. If you have a large deck with several features, including stairs, balusters, or multiple levels, you can expect to spend up to $7 per square foot for labor.

Cleaning and Powerwashing

One of the most important tasks to do before sealing a deck is power washing it to clear away dirt and debris, giving the sealant a clean surface to stick to. Power washing a deck costs about $280 if you hire a pro. While you can do this yourself for a lower cost, it can be dangerous.

If you’re resealing a deck, you may need to take on sandblasting or dustless blasting a deck to remove old layers of sealant. This task usually costs about $2 per square foot and is also best left to the pros. Improper sandblasting can damage your deck and may irritate or injure your eyes, skin, and respiratory system. 

Staining

The cost to stain a deck ranges from $550 and $1,250, or around $850 on average. Generally, deck stain costs between $1 to $2.50 per square foot. With size being the biggest factor determining staining costs, a smaller deck that's around 100 square feet might cost just $100 to $250, not including labor. However, decks that fall into the larger category above 500 square feet could cost as much as $2,500 to stain if you hire a pro.

The age of your deck also influences costs for staining services. While the smoother surface of a newly built deck makes staining pretty straightforward, the roughness and dirtiness of an older deck will demand more prep work. As a result, contractors typically charge around $4 per square foot to stain new decks that are getting a "first" staining. Older decks that require pressure washing and sanding before new stain can be applied will need staining services costing around $5 per square foot.

Those cost estimates factor in both the labor and materials needed to stain a deck. If you're pricing out a project based on labor alone, expect contractors to charge between $40 and $70 per hour for staining. With the average staining job taking up to 20 hours for larger decks, labor often takes up $800 of the total project cost.

The type of stain you choose for your deck also impacts cost. Here's a rundown of average costs by stain type:

• Water-based deck stain: $20–$90 per gallon

• Oil-based deck stain: $35–$120 per gallon

• Solid deck stain: $25–$70 per gallon

• Clear deck stain: $25–$60 per gallon

Deck Sealant Type Costs

Deck sealant costs around $20 to $40 per gallon for oil- or water-based sealer products, while hybrid products that stain and seal the deck at the same time cost slightly more, around $30 to $60 per gallon.

Oil-Based Sealant

Oil-based sealant tends to be the least expensive option at $0.15 to $0.20 per square foot, but it is more difficult to apply. Applying them to even a slightly damp deck can lead to bubbles on the surface. Oil-based sealant takes longer to dry than water-based sealant, but it can better withstand harsh weather conditions and may need to be reapplied less frequently.

Latex Acrylic Sealant

Latex acrylic sealant costs $0.20 to $0.25 per square foot. DIYers love latex acrylic because it’s non-toxic and resists stains, UV rays, and high temps. Latex acrylic lasts longer than oil-based sealant but is difficult to apply without the help of a pro.  

Stain/Sealant Hybrid Products

Stain/sealant hybrids cost about $30 to $60 per gallon. While deck stains are pigmented and bring rich color to a wood deck, a stain is useful for protecting against moisture and weather. These products are typically a sealant with added pigments to restore or add color to the wood deck while also offering a protective coating.

Cost to Seal a Deck Yourself

Sealing a deck yourself costs about $25 to $400 total depending on your deck size, or $0.25 to $1 per square foot, for the materials. Sealant is $20 to $60 per gallon, and most decks need two gallons of sealant to cover the surfaces with two thin layers. You’ll spend another $50 to rent a power washer or $100 to $500 to buy a power washer if you don’t already have one.

Cost to DIY vs. Hiring a Pro

Hiring a professional deck refinisher near you will cost $0.50 to $3 per square foot for labor, or around $40 per hour. You can save about 75% of the project’s total cost if you DIY instead of hiring a professional. However, the pros already have the equipment needed and will ensure the sealant is thoroughly and evenly applied to give your deck the best protection against water and inclement weather. 

While you can certainly take on this task yourself, any mistakes will be fairly obvious every time you have a backyard barbecue.

Cost of Common Deck Sealing Add-Ons

Aside from sealing the deck, there are several other projects you can tackle at the same time. At a minimum, many homeowners choose to stain and seal a deck at the same time. You may also want to make deck repairs and power wash the deck before you start sealing, or you may install a new deck that requires stain and sealant.

• Cost to stain a deck: $550–$1,250

• Cost to power wash a deck: $185–$385

• Cost of deck repairs: $800–$3,200

• Cost to install a new deck: $4,125–$11,650

• Cost to install an above ground pool: $1,050–$5,900

3 Ways to Save Money on Sealing a Deck

Sealing a deck is a worthwhile investment that keeps your outdoor space in good condition. But the cost can be steep, especially if you need to reseal your deck every year. Here are a few tricks to saving more on the cost to seal a deck.

1. Do the Prep Yourself

While you should leave sandblasting to the pros, you can clean or power wash the deck yourself to save up to $400 before applying sealant. Just be sure to use extreme caution when power washing the deck, as the powerful water can cause injuries if you aren’t careful.

You can also remove deck furniture, plants, and other obstacles from the deck yourself to also save more on labor costs.

2. Apply Thin Coats

It’s tempting to apply one thick coat for better protection, but you could end up spending more on sealant by doing so. Plus, a thicker coating is more likely to begin peeling sooner. Instead, apply one thin coat, letting it dry completely before adding a second coat.

3. Consider DIY

If you have a smaller deck or a simple deck setup, like a deck without a lot of balusters or stairs, you can apply the sealant yourself to save 50% to 75% of project costs. Make sure to take the time to make any necessary deck repairs, strip old sealant layers, and clean the deck before applying the sealant.

Deck Waterproofing Tips

Some simple tips can keep your deck protected against moisture. First, don't seal your deck immediately if you've just had a new deck built. It's recommended that you give the deck 30 days to settle before applying sealer. Sealer should be reapplied every one to three years in order to maintain waterproofing.

If you want to maximize the waterproofing benefits of sealing your deck, avoid applying sealer to a damp or frosty deck. These conditions can cause an uneven, streaky seal that doesn't actually leave your deck protected. It's important to let a full 24 hours pass after rainfall before applying sealer.

Pay attention to the thermostat on sealing day. Ideally, sealing should happen on a non-windy day with temperatures between 50 and 90 degrees Fahrenheit. Avoid hot, high-sunshine days that could cause your sealer to evaporate before it fully dries and settles after application.

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We’ve surveyed thousands of real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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