When left exposed to the elements, raw wood doesn’t survive very long in most climates. While some types of wood, such as redwood, are more resistant than others, water, UV, and temperature still take their toll, causing cracks and making it vulnerable to insects, fungi, and other agents of natural decay. Because of this, it’s important to seal and maintain the wooden components of your backyard swing set.
Depending on your particular needs, there are a number of different ways to treat your swing set. Different kinds of treatments depend on your preferred look, the amount of time you’re willing to invest now, and how much maintenance work you’re willing to do in the future
Paint is a simple and popular choice for many backyard swing sets. It’s inexpensive, lasts a relatively long time, and provides an excellent barrier against both moisture and light damage. Furthermore, cracked or peeling paint is easy to spot, so it isn’t hard to tell when maintenance is necessary. Unfortunately, it does have a few downsides.
Paint is so effective specifically because it forms a thick opaque barrier over the wood. This hides the wood beneath, which many homeowners find aesthetically undesirable. Furthermore, paint that isn’t properly maintained will eventually peel, and potentially leave paint chips within easy reach of your kids.
Varnishes are a very popular choice because they provide many of the same benefits of paint without disguising the wood beneath. It sits on top of the wood, providing a firm barrier against the elements that often lasts for several years before reapplication is required. Unfortunately, it isn’t always obvious when a varnish needs to be reapplied, though it may turn a milky color when water begins to penetrate it. To resurface a varnished surface, you’ll need to lightly sand the existing layer (to smooth it and to remove any damaged varnish) before reapplying.
Oil works differently than other treatments in that it doesn’t form an external barrier against moisture and light. Instead, it soaks down into the wood and dries there, blocking moisture from within, and protecting against mold and mildew. Oils that are sold specifically for this purpose also contain pigments that are designed to protect the wood from UV radiation.
While this is an elegant solution that leaves wood looking very natural, it does need to be reapplied relatively often. In most cases it should be reapplied annually or, in some climates, semi-annually.
Epoxy with Varnish
The most durable treatment available is varnish applied over several coats of epoxy. Epoxy completely seals the wood and prevents the natural expansion and contraction of wood exposed to the elements. This limits damage the the varnish on top, which performs its usual function of providing a barrier against water and sunlight. Sealing wood this way is very labor intensive and difficult to do correctly without allowing any contaminants in between the many coats of epoxy and varnish. Done correctly, however, it can be effective for many years before any maintenance is required.