If you have wooden outdoor furniture for your decks, patios, and swimming pool, it must be waterproofed to keep it safe from the elements. If you waterproof wood furniture, it will stay in great shape for longer.

In this article, we will provide you with a complete guide on how to waterproof wood furniture for outdoors, what materials you should use, and why it is essential that you waterproof your furniture in the first place. 

Why Is It Important To Waterproof Outdoor Wooden Furniture?

Waterproofing wooden furniture is essential because it can quickly rot, crack, and warp if left untreated. This applies to outdoor furniture and wood surfaces, including the deck, patio, or shed.

Waterproofing wooden outdoor furniture will do much more than just protect it from water damage. You can treat your outdoor wooden furniture to protect it from humidity, frost, UV rays, insects, and other severe weather conditions.

Of course, nothing will make your wooden furniture entirely immune to the weather influences, but it can absolutely help to keep it in its top shape for an extended period of time. 

What Types of Wood Should You Use for Outdoor Furniture?

Teak, cedar, ipe, and redwood are the types of durable wood primarily used for outdoor furniture making. All these woods naturally have moisture-wicking properties, making them an excellent choice for all weather conditions.

Choosing the right wood for your outdoor furniture is imperative since you need a wood type that can resist decay for a longer time compared to the wood typically used indoors. Even though the types of wood used for outdoor furniture are more expensive, they are worth buying since they offer a longer lifespan.

How To Waterproof Wood Furniture for Outdoors?

The quickest and most convenient way to waterproof wooden outdoor furniture is by using a wood stain or sealant. The wood stain's pigment will give the wood a fresh new appearance, while the sealant will deliver the furniture a shine with a transparent finish. Both methods are equally good in waterproofing outdoor wooden furniture. Both methods must be regularly reapplied every two or three months.

Here are five of the best methods to waterproof wooden furniture for the outdoors. Keep reading below. You can get the required tools for each here.

Varnish

Varnish gives a scratch-resistant finish to outdoor wood furniture. It does not crack easily, is flexible, and does not turn the furniture pale with time. It consists of drying oil, solvent, and resin.

The best varnish to use on outdoor furniture is marine varnish, which protects the furniture from harmful UV rays and moisture.

Here is how you should apply varnish to your wooden furniture:

• If your furniture is old, consider sanding it with rough sandpaper, a mixture of grit, and an orbital sander.
• Clean the furniture with a rough brush or scrub, using deck cleaner mixed in warm water. Rub it with a dry cloth.
• Apply a thin coat of varnish with a paintbrush and leave it to dry overnight.
• Apply another thin coat and leave it to dry. Do this for up to 8 coats.
• After drying completely, apply the final coat and wait 24 hours for the varnish to dry. 

Polyurethane

Polyurethane can be simply defined as liquid plastic. Once applied and dried completely, it offers an excellent finish to the wooden furniture, is scratch-resistant, and is water impenetrable.

Two types of polyurethane are used to coat wood: oil-based and water-based polyurethane. If you are using polyurethane to paint your outdoor furniture, make sure you apply oil-based polyurethane for maximum protection against water and other outdoor elements.

The finish on the furniture with polyurethane is almost the same as the marine varnish finish, except that it only requires 2-3 coats instead of the eight coats required with Marine varnish.

You should also be careful while using polyurethane since it contains volatile compounds which can cause health issues and irritation. Be sure to use this sealant in a well-ventilated area when applying it to your furniture.

Here is how you should apply polyurethane to your wooden furniture:

• Follow the first three steps used in the varnish section and come back here.
• Using a natural bristle paint brush, apply the first thin coat of polyurethane to your outdoor wood furniture.
• Leave it to dry overnight.
• Finally, apply the last coat, and dry it for at least 24-28 hours.

Lacquer

Synthetic or natural resin mixed with alcohol is called lacquer. It has a thinner consistency than polyurethane and varnish. This means that it provides more protection than the two materials mentioned above and penetrates more deeply into the wood.

Lacquer suits darker shades of wood best, giving a hard, scratch-resistant finish with a warmer touch. Among other types of sealants, lacquer dries the quickest, which makes it less time-consuming when applied to wooden furniture.

Here is how you should apply lacquer to your outdoor wooden furniture.

• Remove any coats applied before to your old furniture with the help of rough sandpaper.
• Wipe the furniture with a brush using a mixture of deck cleaner and warm water.
• Apply a thin coat of lacquer and leave it for about 2-3 hours to dry completely.
• Apply the final coat and wait till it dries in another 2-3 hours.

Stained Sealant

If you are short on time, using a stained sealant is one of the best ways to waterproof wood furniture outdoors. Once it is stained, the sealant will also give your furniture a rich color with a scratch-resistant finish and maximum protection.

Typically in sealant stains, the type of sealant used is mostly polyurethane. You can choose the consistency and the concentration of pigment in the stain. The finishes can range from glossy, opaque, flat, and transparent.

Applying a stained sealant requires the same steps as the materials mentioned above, except that it takes only 8-9 hours to dry completely when left for 24 hours after the final coat.

Natural Oils

Using natural oils to coat your wooden outdoor furniture is perhaps the most convenient and quickest way to waterproof it from the elements. Unlike the materials mentioned above, natural oils are free from any toxic volatile compounds, with no risk of health problems.

It should be noted that compared to varnish, polyurethane and other sealants, and natural oils offer lesser to moderate levels of protection.

The most used natural oils for waterproofing or wooden furniture are tung and linseed oil (polymerized or raw).

What Is the Durability of Different Types of Sealants?

Below we break down the durability of the sealants mentioned above for waterproofing or weatherproofing wood:

• Varnish: Waterproofing wood with varnish usually lasts 2-3 years, requiring reapplication after this duration.
• Polyurethane: This type of sealant lasts more than 5-8 years before needing reapplication.
• Lacquer: In many sheen options, lacquer offers excellent durability, often lasting around 10-15 years before reapplication.
• Stained sealants: Their application offers protection for up to 5-10 years.
• Natural oils: They require a retouch every six months, unlike the other sealants.

How Can You Weatherproof Painted Wood Furniture?

Weatherproofing painted furniture is quite an easy process including the following simple steps:

• Prepare a mixture of deck cleaner and water and with a brush clean the furniture.
• Wash the furniture to remove the excess mixture and let it dry for a while.
• Rub it off with a dry cloth.
• Now apply your desired sealant, and then use a primer to maximize the sealant's durability.
• The best suitable adhesive to weatherproof painted wood is polyurethane and varnish, with a natural bristle paint brush.

Things To Remember

Here are a few things to keep in mind before coating your wooden furniture to protect it from outdoor elements: 

• Not all wooden outdoor furniture requires  waterproofing. That is why it is a good idea to do your research beforehand. For example, wood types such as teak do not need any maintenance.
• Weatherproofing wood that is painted requires an additional step: you must clean it with a wood-safe detergent. Leave the furniture to dry for at least 4 hours before moving on to the next step.
• Research the type of sealant you want to use on your wood furniture. Some sealants give the wood a matte finish, while others offer glossy finishes.
• Always opt to do all painting work in well-ventilated areas. This is because the fumes from the sealants can release volatile compounds, which can be toxic. 
• Always wear a mask and gloves during the process for maximum protection.

Final Thoughts

The ideas and tips mentioned above are constructive for those who want to learn how to waterproof wooden outdoor furniture. Remember to repeat the painting process every few years, as required, according to the type of sealant you use.