3 Ways to Waterproof Wood Furniture for Outdoors

By MWB-Team •  Updated: 06/16/23 • 

Waterproofing wood furniture helps protect it from elements that might leave it warped, cracked, or deteriorate over time. If you have wood furniture on your patio, balcony, deck, or any outdoor space, waterproofing reduces damage from the elements and keeps it in good shape for a long time.

If you want to waterproof your wood furniture, you’re in the right place. In this article, we’ll take you step-by-step through how to waterproof your wooden furniture for outdoor use. However, before we get into the part of applying a waterproof coat, here’s how to prep your wood furniture.

Prep Wood Furniture for Waterproofing

Cleaning the Wood

Before waterproofing your wood furniture, you must clean it thoroughly to remove any debris and dirt. If your wood furniture is finished, strip it or sand it off before applying the waterproofing coat.

Once you’ve cleaned your furniture, allow it to dry up completely before sanding it or stripping the old finish.

Sanding or Stripping

Once dry, sand or strip the wood furniture; we prefer sanding over stripping. Sanding your wood furniture, even lightly, will remove the existing coat and also allow the waterproofing coat to be absorbed or stick better.

If your wood furniture is unfinished, sanding it even a bit can also help the waterproofing coat absorb better. Sanding will open up the pores, thus helping the wood absorb the new waterproofing sealant better.

Sanded Outdoor Log Table

Sanded Outdoor Log Table

Once you’ve cleaned and sanded your wood furniture, wipe it clean or blow it off. This removes the dust and dirt from sanding from being sealed into your wood furniture. Ensure there are no scuffs or stains because once you apply the waterproofing coat, they will be much harder to remove.

If everything looks good, you can waterproof your wood furniture.

Waterproofing Your Wood Furniture

Before waterproofing your wooden furniture, there are three methods you should choose from. These are using sealants, oils, or a stain and sealant combo. All these have their pros and cons., which we’ll talk about to help you choose the best for your needs.

1. Using Sealants

Polyurethane and varnish sealants all have good waterproofing properties. All these sealants are reliable and will provide excellent waterproofing properties to your outdoor wood furniture when used.

Polyurethane

Polyurethane there are both oil- and water-based for outdoor use. These two provide different finishing effects.

Oil-based polyurethane dries slowly and can take up to six hours before you can apply a second coat. However, once finished and fully cured, oil-based polyurethane provides excellent protection against abrasion and scratches, which makes it good for wood floors, outdoor furniture, and other places where durability is critical.

Outdoor Bench Sealed With Polyurethane

Outdoor Bench Sealed With Polyurethane

Depending on the number of coats you apply, oil-based polyurethane will leave a slightly yellow sheen, which might be desired in some applications. However, if you want to preserve your wooden furniture’s natural aesthetics, choose water-based poly.

Water-based polyurethane dries fast, and more coats can be applied quickly. However, you’ll need to apply more coats to get a hard protective film like oil-based poly. Water-based poly starts as milky-white, but as it dries, it becomes clear without imparting any color to the wood. Apart from leaving your wood looking natural, water-based poly has low odor and VOCs.

Check out our best outdoor polyurethane you can use to protect your wood from different elements such as rain, ultraviolet rays, temperature changes, and much more.

Varnish

Varnishes combine drying oils (Like linseed oil), tree resin, and a solvent like alcohol. Once applied to your wooden furniture, varnish hardens to a scratch-resistant finish that does not yellow over time.

Apart from protecting wood from water and moisture, varnish protects against UV. However, it requires more coats to offer protection because it is thinner. It also takes a lot of time to dry and will emit VOCs during application and when drying.

Interior/Exterior Marine Spar Varnish

Interior/Exterior Marine Spar Varnish

For outdoor use, look for a varnish with high UV resistance. Look for spar varnish, marine varnish, or spar urethane, which all mean the same thing. Varnish is available in different sheens, but it is naturally glossy.

2. Using Oils

Linseed oil and tung oil are the two common oils you can use for waterproofing wood. These oils have been around for a long apart from waterproofing; they improve the enhance the beauty of wood. Because oils can turn yellow over time, using them on darker woods is better.

Most oils for outdoor use are usually blended with poly and mineral spirits to enhance their durability and waterproofing properties. Blending oils with poly, mineral oil, and other ingredients also hastens the drying time and makes the finished wood less sticky. You can also create your custom blend by mixing poly and mineral spirits.

You can apply oils to wood using a brush and wipe off the excess finish with a clean cloth. Oil will take longer to dry, so leave it for about 24 hours before applying a second coat.

3. Using a Stain-Sealant Combo

A stain and sealer combo is recommended when you want to enhance the natural beauty of the wood or change its appearance.

Lighter stains are good for showing the natural beauty of the wood while also waterproofing it. However, if you want more than waterproofing, solid stains offer waterproofing and better UV protection.

There are oil- and water-based stain sealers. Oil-based stain sealers give the wood a more natural look and soak into the hardening over time. However, oil-based stains are harder to apply and take longer to dry. When the conditions are right, oil-based stains can cure in around 4-6 hours before you apply a second coat.

Behr Premium Semi Transparent Waterproofing Stain & Sealer

Behr Premium Semi Transparent Waterproofing Stain & Sealer

Water-based stain sealers are more solid and come with different vibrant colors. They sit on top of the wood, forming a protective coat. They are also easy to apply with very few imperfections, like blotchiness. They dry quickly; you can apply different coats faster than oil-based stains.

When applying oil- and water-based stain sealers, ensure the weather and temperatures are right for the best results. It should neither be too sunny nor cold, which might affect how the stain soaks or settles into/on the wood.

MWB-Team

Hello there! This is the Make Wood Better Team. Here, we share informative how-tos and guides focused on making wood better. Whether it's finishing wood, maintenance, or restoration, there's something on this website for you to learn and improve your skills.