Do You Need To Varnish Wood Outdoor Furniture? Here's What You Should Know

Placing wood furniture outdoors and exposing it to the elements can seem a bit tricky, since things like moisture and sunlight can affect the finish. It can be helpful to locate some of the best outdoor furniture brands for longevity. You may also be wondering if it's necessary to use varnish for your wood's strength and beauty. The short answer is that yes, varnish can be an excellent protection for your wood furniture; other options like penetrating oils also work to weatherproof your wood. It depends on things like your preference when it comes to how it looks, application, wood type, and maintenance upkeep, since varnish may not always be the preferred method. For maximum protection, choose spar, marine, or exterior-grade polyurethane varnish, but if you like a more natural look to your wood, penetrating oil is a better option.

Wood becomes damaged when water or UV rays from sunshine get to it, because these two things separate the fibers, fading or rotting the furniture. Varnish, when applied, lies on top of your wood to keep the elements out and your wood safe. However, there are different types of varnishes to choose from, and they are not all created equal. Oils help create more of a perfect looking wood finish. Exploring varnish or oil treatments to apply to your wood ensures that it is protected and that it will last a long time.

The best protection for outdoor furniture is a spar or marine varnish. These are primarily designed for boats, but it's a flexible varnish for wood that accommodates expansion and shrinkage due to temperature changes, moisture, and sunlight. It dries clear so you can see through it, creating a noticeable film on the surface. However, it requires at least five coats to build the best protection, so it can feel tedious and time consuming.

Exterior-grade polyurethane is another durable varnish that leaves a golden tint over your wood. It works well for furniture that sees a lot of rainfall or sprinkler sprays. You will need specific tools for applying two to three coats, including a fine-bristle brush and sandpaper, since it creates a lot of bubbles that need smoothing. Penetrating oils (instead of varnish) give your wood an organic look with a few coats without the film on top , but still provide great protection, especially against UV rays. The finish is also less likely to crack or peel since it absorbs deeply into the wood. Not all oils are the same, so be cautious about using something like coconut oil to seal your wood furniture. It may also depend on your wood since certain types, like mahogany, require specific oils.

Varnishes will need reapplication every year, though this may also depend on your wood furniture. Look for signs that it's time to reapply varnish, such as water being absorbed into it, fading of your finish, or feeling rough. Maintenance for most penetrating oils should be every year as well. Keep in mind that some oils, like teak or tung, that penetrate deeper into your wood need more frequent reapplication, every three to six months.