Choosing Exterior Wood Sealers for Decks, Siding, Raised Gardens

Aug 15, 2010
Kelly Smith

Cedar Picket Fences may be Stained for Longevity - Kelly Smith

Wood is a versatile building material, but must be protected from the elements to avoid rot, and against pests to avoid carpenter ant and termite damage.

The choice of a wood sealer depends on many things. Should it bring out the beauty of the wood grain in Adirondack chairs or patio furniture? Does it need to be organic and non-toxic for backyard decks or raised bed gardens? Should it incorporate a colored wood stain for siding? The choices on the market today are greater than ever.

Sealers for Decks and Raised Bed Gardens

These products should be chosen carefully since they come in direct contact with human adults, children, and pets. One of the newest on the market is the Non-Toxic Wood Treatment Wood Sealers from CedarCide. The company calls these products wood stabilizers and claims to provide a one-time, lifetime treatment.

In fact, they put it this way, “Our cedar oil based, organic wood treatment products are safe and non toxic to people, pets and the planet. Our natural pesticides offer homeowners treated wood alternatives that are 100% non toxic. All of our non toxic wood treatment products for deck and garden applications feature perpetual protection from termites, carpenter ants, wood rot, and fungal attack.”

Exterior Wood Finishes for Patio Furniture

Wood patio furniture needs different considerations than the the metal, plastic, or PVC varieties. The idea here is to not “coat” the wood as a paint will do, but to actually penetrate the outer cells of the wood surface, effectively sealing out moisture and protecting from damage from bumping, dropping, etc.

One of the best and most traditional is tung oil. Although the various formulations are different today, the original was produced from the nuts of tung trees and the Chinese used it to seal their wooden sailing ships.

Another close cousin is Danish oil. This is a varnish/oil blend, so it provides some of the penetrating capability of tung oil although it will usually dry somewhat faster. When talking about these wood finishes, it should be mentioned that neither of these types of oil should be used on butcher block countertops, “just because it's handy.” Only food-quality mineral oil should be used for food-contact wood surfaces.

Wood Siding Finishes

These finishes are generally clear or have stain added in a range of shades far too broad to go into here. Since high-quality wood siding is expensive and performs an important task for the home, it's best not to skimp on a sealer/finish. In addition to siding, some homeowners choose to finish a cedar picket fence to match the siding.

When deciding on a brand, just be sure to go for high quality names such as Benjamin Moore, Behr, Cabot, etc. In addition to any stain built into the sealer, some contain specific UV protection. This is an industry that has really matured over the years.

When working with new siding, all surfaces need to be primed/sealed. This includes the back, sides, ends, and cut surfaces. This process is called backpriming and is done to ensure that no moisture can come into contact with any part of the wood. If a building contractor is doing the job, insist on this step. The bottom line? Take care of all exterior wood products.