The best ways to seal exterior wood

Wood is a porous material and it absorbs water quite easily. Rain and humidity can cause irreversible damage and cause it to warp, swell, and finally rot. Hence, one must coat the wood surface with the best water sealant to preserve its natural beauty. Coating exterior wood surfaces such as your fence, deck, and outdoor furniture will enhance its life span significantly.

A wood sealant not only extends the life span of the wood but greatly enhances its overall appearance as well. Wood sealants are available in the form of paints, stains, or water-proofers. However, it is highly recommended to use a blend of sealer and outdoor stain for coating your outdoor wood.

Outdoor wood sealing guide

Wood is available in great variety. Whether you are using cedar, cypress, redwood, pressure-treated, or high-end exotic hardwood, each of these types needs the right care and maintenance. Here are a few points to consider under the outdoor wood sealing guide

1. Choose the right coating

  • Exterior grade penetrating stain

Such a stain is one of the most popular outdoor wood coatings that people tend to use for their outdoor furniture and fences. These coatings are excellent water repellent preservatives that contain mildewcide, while some variants contain UV ray absorbers that protect your exotic wood from sun exposure. Such stains are available in oil and water-based formulations. The resin penetrates and blocks pores to prevent moisture from seeping into the wood.

  • Film-forming sealant

This type of sealant bonds to the wooden surface like paint or shellac. Such a sealant is the one for you if you are expecting a high-gloss furniture look. It protects your exterior wooden furniture from harsh weather conditions while allowing the natural grain to show through. It is also available in water and oil finishes and offers a durable and elegant satin surface.

Such a sealant can only be maintained when you put another coat of film-forming sealant. One can add his pigment of choice to change the wood color and add UV ray protection. However, one must not apply a film-forming sealant on floors since the film wears off with foot traffic.

2. Treating different types of wood

  • New Wood

Newly pressure-treated wood must be thoroughly dried before staining or sealing. The moisture present in the wood can obstruct the penetration of stains or paints. Hence, the treated wood is allowed to dry for 2 to 4 weeks before application of stains or paint coatings.

It is not always easy to determine how long the treated wood will take to dry. The drying process has a lot to do with the weather conditions, humidity, and the lumber’s exposure to the sun.

Certain types of wood such as cypress, redwood, and red cedar do not need a lot of time to dry since such types of wood are not pressure treated with a preservative. On the other hand, new wood needs to be cleaned with oxygenated bleach to remove any mill-scale that forms during the milling process. It is because the stain or paint will float on the mill–scale and run off without absorption if the surface is not cleaned.

  • Weathered wood

Wood tends to get damaged due to exposure to sunlight which turns the wood surface gray. The surface can be renewed either by sand or pressure-washing. However, one must limit the pressure to no more than 1,000 or 1,200 PSI, otherwise, it can cause the surface to splinter or fuzz. Once this happens, it will pose a touch hazard in deck areas where people walking barefoot can get injured.

If a few individual boards are heavily weathered, it is recommended to have them replaced. You may clean the existing boards and stain them along with new boards to match.

  • Wood with an old seal

One must remove the old sealant from the wood surface before applying a fresh coat. It is because the old stain will show through the new stain leaving blotches on the finish.

Film-forming stains must be removed completely before you apply a penetrating stain, or else the resins from the penetrating stain will not be able to enter the wood pores. On the other hand, if there is a buildup of old stains on the deck area, it needs to be removed with something much stronger than oxygen bleach cleaner. 

One can use stain strippers that are much more caustic, but they remove weathered stains in a single application. Finally, small stains can be easily removed with a hand sander when the deck has dried.

3. Conditioning

One of the key steps for outdoor staining is the application of a wood brightener. The solution opens up the wood grain to improve penetration of the stain and restore the look of weathered wood.

Finally, you should apply a stain or sealer with a brush to dried wood and work the product into the wood grain. However, do mix the stain so that all the ingredients are well blended and ensure a consistent color tone throughout the entire project.

So, practice these guidelines to ensure the most consistent appearance and best protection for your exterior wood.