How to Protect Your Exterior Wood

Weathering happens naturally. It’s a process that breaks down materials, including wood. The process can be sped up due to exposure to biological components, water and changes in the atmosphere. It’s important to take steps to protect your timber from weathering. As time goes by, external wood can begin to show signs of being exposed to the previously mentioned elements. Some people don’t mind what their wood looks like after being exposed to elements, but many people think it is not a good look.

It’s a good idea to have an understanding of how natural elements within your garden can affect your exterior wood. You’ll want to know what types of products you can use to help you protect your wood. Don’t worry though because we’re going to provide you with some useful information and guidance that can help you.

When external wood is subjected to weathering, then it can become less aesthetically appealing. Not only that, but water damage can lead to costly repairs. The good news is there are varnishes, oils, stains and paints that can protect your wood from water damage and other elements that can potentially cause damage.

Rain: What Can It Do To Wood

Rain can cause wood to rot. This is especially the case with wood that doesn’t have enough natural oils to protect against rain. Moisture can lead to a breeding ground for microorganisms.

Natural oils can be found in redwood and cedar. However, they can still be at risk for rain damage if conditions are extremely wet or very shady. In turn, fungi and algae could end up growing.

A finish is typically required to protect wood from rain and rot. You’ll want to choose a high quality wood oil, which can protect wood and aid the wood’s natural character. A varnish can be used to, and this will create a waterproof and tough seal.

Moisture can easily be absorbed into the wood’s cell if the wood isn’t protected. In turn, the wood can expand and swell up. Cells can shrink when the wood is exposed to heat and warmth. Eventually, the wood could become cracked and warped.

Why Protection From The Sun Is Necessary

Wood can become exposed to UV rays, which can cause a tremendous amount of damage. If wood is exposed to the sun’s rays, then its fibres could become damaged. In turn, the wood will be highly susceptible to cracking.

The first thing that will likely catch your eye is a colour change in the wood. Wood reacts to light due to being photosensitive. You’ll probably notice that the wood is grey in colour, if it has been exposed to UV rays. If you want to protect your wood from UV rays, then consider getting a high quality finishing product.

Stop Wildlife From Attacking Your Wood

Finally, your garden probably contains a number of insects, especially wood-boring insects. These are insects that find their way into untreated timber. Such insects can cause timber to weather, as well as cause long-lasting damage. Insects tend to be attracted to places that are located in areas that doesn’t have low humidity and/or high ventilation.

You should use a wood preserver. A good preserver can protect your wood from insects. They contain chemicals such as insecticides and biocides. These chemicals protect the grain of the wood from various biological threats.

Here’s a tip: keep your wood away from shaded and damp conditions. Dry timber tends to do a better job at deterring insects. In turn, it won’t be at high risk of getting damaged.

Why does outdoor wood require protection?

When you own outdoor wood furniture, you will see that it faces various weather elements, such as rain, dampness, sunlight, wind, snow, and more. No matter your temperature, your outdoor furniture will meet the elements. Therefore, outdoor future is liable to feature scratches, cracks, discolouration and other deterioration more than indoor wood furniture because it faces weather elements. There are also other things like wood boring insects.

Therefore, all outdoor wood requires protection from the elements. The only caveat is if you choose to let your outdoor furniture age naturally. However, unprotected wood will face mildew and decay and eventually have to be replaced. All outdoor furniture will ultimately break down and have to be renewed. However, there are solutions that you can use to protect outside wood furniture and make any damaged surface look good all year round.

Wood Sealers

If you want to protect your wood, use a wood sealer to protect your outdoor furniture from rotting and weathering. These work similarly to pressure treatment, however, without the pressure. When you examine wood sealers, they typically contain plastic/acrylic compounds. The compound is poured onto the wood, and then it must soak. After drying, you will find that the top few inches of wood are covered in plastic inside and outside the surface.

When it comes to wood sealers, they are easy to apply and only have to be reapplied every one to five years.

If you choose this option, know that softer wood is more porous. Because of this, this softer wood requires more sealer for adequate protection. On the plus side, the sealer will soak in deeper when working with softer wood.

Using a wood sealer is simple:

Step 1. Clean the wood’s surface and sand it lightly.

Step 2. Apply the sealer generously to the surface. Use a brush or use a cloth to dab it on. You can also use a spray gun. Do not, under any circumstances, leave visible streaks in the sealer.

Step 3. Let the sealant dry completely. Look at the product’s label to see how long the process will take. It’s typical for the process to take 24 hours. Some products will dry more quickly.

Step 4. Sand the surface again, but do it lightly. Then, apply another layer of sealant. Always use the finest grade of sandpaper possible.

Step 5. Let the second layer dry. After that, apply a third and fourth layers.

Put on an outdoor-rated finish. Use lacquer, varnish, polyurethane or epoxy.

There are many options for outdoor finishes. The four most popular are lacquer, varnish, epoxy, and polyurethane. Depending on the product, application techniques will vary. However, you’ll have a general idea of how to apply the finish.

Completely clean the wood before applying the finish. If you’re working with wood that is already finished, sand it before using a new finish.

Note: if the same finish is being applied and it’s not too old, you won’t need to sand it off. All you’ll need to do is thoroughly clean the exterior wood.

Wood finishes, for the most part, last several years. They’re not permanent, but the longevity of the exterior wood increases. After you treat exterior wood furniture once, the next time, the process will go faster.

Here is the material list. The list is not complete, but you’ll cover the basics.

What You Need

The finish you choose: lacquer, polyurethane, varnish, or epoxy. (You’ll need to look at the can to determine the finish’s coverage.)

Stick for stirring paint

A paintbrush that is comprised of bristle

Fine sandpaper

The option of an electric sander

A vacuum cleaner


Use a distiller if needed: water to use for water-based sealant and mineral spirits to use for oil-based sealants.

1. Give the finish the light stir.

If too vigorous, stirring can form air bubbles, making things hard to apply.

2. Halfway into the finish, take a bristle brush. Apply as evenly as possible.

Always go with the grain when applying finish. Be sure not to put too much on the brush. If you do, things can drip and be uneven.

3. Allow the finish to dry.

For water-based sealants, give it two to four hours. If you are using a wood oil-based sealant, wait six to eight hours. Overnight is excellent too. Let the finish dry and keep the furniture out of sunlight. Cover it when the months are colder, so rain or snow doesn’t harm it.

4. Finish with a light sanding of 120 grit or finer sandpaper.

Depending on how high the number is will determine how fine the sandpaper is. As you’re applying more coats, use sandpaper of finer grit. For example, you can use finer grit sandpaper after the third coat than the first coat. When you use finer sandpaper, it’s much more gentle on the exterior wood.

5. Wipe excess dust off the exterior wood Surface.

Repeat steps 2-5 until there are three to five coats of finish. How many coats you have will all depend on the finish type.

Oil-based finishes need fewer coats than water-based ones.

Remember that this is a general guide to applying a finish to outdoor wood furniture. Always look to the instructions from the manufacturer when you are about to apply the finish. Keep in mind that all finishes vary from one another.


Polyurethane is a resin that is durable and plastic. Polyurethane sealants are found in various styles, such as satin, gloss, and semi-gloss. Satin is the least bright of the three. High gloss finishes have a shine.

When you treat exterior wood, you can use water-based or oil-based polyurethane. The oil-based sealants take longer than the water variety. However, not as many coats are needed. The material is higher in VOCs than water-based.

When you use oil-based polyurethane, it needs turpentine, mineral spirits, or acetone to clean it up. When you work with water-based polyurethane, it cleans up with soap and water.

You can use polyurethane for indoor or outdoor use. You can use outdoor sealant indoors, but not vice versa. Therefore, ensure you have the correct product before starting your project.


The ultra-durable high-gloss lacquer finish is created by dissolving tree sap into turpentine or alcohol. Lacquer comes in multiple sheens. Lacquer thinner makes a lacquer that is easier to put on exterior wood finishes.

Applying three to five coats of thin lacquer to the exterior wood is recommended. Keep in mind that the fumes are pretty intolerable. Therefore, ensure you open the windows and doors when applying the product.


Varnish comprises drying oil (linseed oil, for example), tree resin, and solvent (alcohol, for example.) When applied, the varnish hardens as the solvent evaporates. Some varnishes will set fast based on the solvent, while others take time. Be sure to avoid excess oil when using sealant wood oils.

Varnish is very water and UV-resistant. It is thinner than most other polyurethane solvents. More coats are needed, and it can take a long time to dry. Varnish is found in a wide variety of sheens despite being naturally glossy.

When you intend to treat outdoor wood furniture, make sure the varnish has high UV resistance. A good option is a marine varnish. This durable finish is what they use on boats and ships.


What is epoxy? It’s comprised of epoxy resins and organic compounds from plants. The durable finish is often applied before lacquer or varnish.

Be aware that not every epoxy is rated for outdoor use. Every epoxy will turn yellow over time when it is exposed to sunlight. However, those for outdoor use are more UV-resistant.

Investigate your manufacturer before starting your exterior wood job. Some epoxy resins fill in wood cracks as the resin gets into hard-to-reach areas quickly. However, not all epoxies are thin enough. In the above video, a full coat of epoxy was applied, dried and sanded down. Varnish is used afterwards.

Painting Exterior Wood Furniture

When you use paint, it’s an excellent way to give strong protection from the outdoor elements to keep wood furniture looking good. When it comes to sunlight, paint can stop sunlight from getting into the wood’s surface. Paint also blocks UV rays and protects the wood underneath from discolouration and other issues.

For better long-term protection for outdoor wood furniture, latex paint gives better protection than traditional oil-based paint. Latex paint is used for cosmetic repairs and is applied easily. You can find latex paint in various colours to hide scratches. If you give your exterior wood a good coat of paint, you’ll protect it against outdoor elements, such as water and UV radiation.

Even after you’ve painted your outdoor wood, inspect the wood for dents, scratches, peelings, and fading every few months. Then reapply the paint over the surface.

These are the drawbacks and benefits of using paint to protect outdoor furniture from the elements.


Lots of colours are available.

You get UV protection.

You get moisture protection.

Routine maintenance is not needed.


The appearance of a woods natural colour is hard to achieve.

Applying it takes a long time.

Wood loses its original colour. Some would instead use alternative methods to protect the wood from the elements. Let’s examine how sealing outdoor wood furniture helps protect it from the elements.


Covering outdoor wood furniture is an easy and straightforward way to protect the furniture from the elements. It is also advised to cover your outdoor furniture, especially when the weather is harsh. This goes even if sealant or paint has previously been applied.

You will physically protect the furniture from rain, moisture, UV rays and other bad weather.

For this task, feel free to use covers for patio furniture, protective mantles, or other suitable fabrics. However, it’s important that it’s all in the correct sizes to cover your entire furniture. It needs to be covered when you’re not using outdoor wood furniture.

Here are the pros and cons of covering your outdoor furniture to protect it from the elements.


Protect wood from UV rays

Protected from rain


This applies only when furniture is not in use.

It’s less resistant to moisture.

As we have outlined, covering wood furniture is an excellent way to protect it. However, covering the furniture without applying paint or sealer is not wise. Consider covering a bonus that strengthens the furniture’s shied against outdoor elements.

Pressure Treatment

This is an industrial procedure that is not an option for DIY projects. The wood is protected with preservatives using a mixture of hot water, pressure, and various preserving agents. The press of the process seeps deep into the wood grain to prevent internal rotting.

Preservatives used in the process are usually copper azalea, alkaline copper quaternary or another copper compound. Copper is resistant to weathering. So it’s no surprise that the ingredient would be used. Suppose you purchase wet-looking pressure-treated lumber, no worries. This water will evaporate, and the preservatives will be left behind.

Keep the Wood Furniture Clean

1. Remove the cushions. Go for zippered pillow covers that are easily hand or machine-washed. If you can’t wash the cushion covers, dust off the surface dirt, then scrub it gently with a sponge or a soft-bristle brush as well as a mixture of dishwashing soap and warm water. Hose the furniture off and allow it to dry out in the sun to stop mildew growth.

2. Wipe it down. Take a damp cloth as result of a mixture of warm water and gentle dishwashing soap; clean the hard plastic surfaces, aluminium, wicker, and cast-iron furnishings. Rinse the furniture by hosing off the furniture.

3. Oil it up. Variations in the temperature can make the teak crack. To prevent further damage, clean with an oil-based soap and a soft-bristled brush. Hose everything off when you’re done.

4. Pull out the vacuum.

Hose down for larger solid pieces but remove the dirt from the tiny crevices with a vacuum cleaner for wicker furniture that’s tricker. Do this a few times each season. This helps with grimy buildup.


There are other methods you can employ to waterproof your wood surfaces. However, we’ve covered the most common methods and given you specific instructions for the methods. Most other methods are “niche” methods. Niche methods are likely not practical for most people. There are other options like wood stain to bring out the woods natural colour or wood preserver. You can even get stain sealant combos.

This article gives you the know-how to preserve your outdoor wood furniture for as long as possible. Don’t assume that you don’t need to treat wood. If you do, you will watch your wood rot away. Instead, use one of the methods described to make your wood furniture last for years.