Decking Materials for Temperature Swings: Choosing Decking for Colorado’s Rocky Mountain Area

The dramatic temperature changes, heavy snowfall, and higher UV exposure of Colorado can take a toll on wooden decks, making durable capped composite decking a wiser choice.

The dramatic temperature changes, heavy snowfall, and higher UV exposure of Colorado can take a toll on wooden decks, making durable capped composite decking a wiser choice.

Over my career, I’ve built structures on three continents and in a wide variety of climate types. I’ve worked under the hot sun of Hong Kong, the dry desert of Arizona, in the long winters of Finland, and the rainy climes of the Pacific Northwest, but I haven’t yet been in a place that combines elements of all of those–except maybe the Rocky Mountains of Colorado. This area presents a challenging climate in which it is difficult to build anything that resists the power of the elements, much less a deck that will be exposed to them. When the sun shines, due to the high altitude, it does so with heightened intensity, exposing humans and buildings alike to about 4% more UV rays per 1000 feet of altitude.

In winter, the amount of snow is prolific. Vail, for instance, averages 190 inches per year. These long, cold, snowy winters are quick to turn cracks in a deck into larger fissures. While there are ways to help your standard wooden deck meet the challenges of Colorado’s difficult four season climate, in the last decade, composite decking materials have been developed that successfully address all of these challenges with hardly any maintenance. Fully capped bamboo-based composite decking performs well against the cold of winter and the blazing heat of the summer sun, resisting moisture and UV rays without becoming warped or misshapen.

Finding the Most UV-Resistant Decking

The sun is one of the primary agents of weathering. At 6,000-8,000 feet in elevation (a pretty normal altitude for CO), exposure to UV rays is increased by 25% compared to sea level. With the highest mean altitude of any state, Colorado elevations make it possible to get a sunburn on a sunny day in the middle of winter. What this means for you is that UV-resistant decking is especially important in this state.

With decking, the first kind of weathering that most people notice is the grey color that wood develops as it ages. You may know that this is the result of the sun’s weathering, but what many don’t know is that the greying is actually a sign of more fundamental damage to the cellular structure of the wood. Once wood has greyed to a certain level it requires a deep sanding down to the level of the healthy non-greyed wood, followed by the application of a UV-resistant stain and a sealer. Composite decking, on the other hand–specifically fully capped composite decking–possesses in its enclosing cap all the UV protection it will ever need, meaning no sanding, no sealing, no staining, and no greying.

Protection from Colorado’s Snow and Rain

Most of the snow-related damage done to a deck isn’t from the cold, per se, but comes about when the snow melts, only to be frozen again. This is a cycle that residents of any state in an area that gets snow are familiar with, but the cycle can be especially dramatic in Colorado. Here, the altitude can cause a big difference between the day’s high and low temperatures, and phenomena like the ‘chinook’ can cause temperatures to rise drastically in a short period of time.

This cycle of freezing, thawing, and refreezing allows water to seep into any crevices it can find. When that water again freezes, it expands within those crevices, ultimately creating large cracks, which are unsightly and can potentially weaken the deck. By persistent force, rain also weathers the wood of a deck. While vertical surfaces are spared much of the erosive force of rain, horizontal surfaces are spared none. For a deck to last a long time, it requires a treatment to keep the water out of those crevices and to keep it from breaking down the surface of the wood.

The solution for wooden decks is a strong sealer, generally applied every other year or so, depending on the wood, the climate, and the type of sealer that is used. As long as the sealer is applied frequently and carefully, a wooden deck will stay in good shape, especially if the shaded undersides of the planks were well sealed when the deck was installed. Capped composite decking, on the other hand, solves that problem with a rigid, impermeable, plastic capping, capable of lasting without maintenance for decades.

Dealing with the Extra Weight of Snow on Decks

When choosing a material for your Colorado deck, keep in mind the other means by which snow breaks down a deck–the sheer weight! Especially in places like Steamboat Springs, with its enormous average snowfall, snow can come down in piles and stay in piles for weeks unless it’s removed from the deck.

When it isn’t shoveled, the weight from the piles will add more than enough weight to warp some of the wooden boards, especially if the piles are unevenly distributed. Weight can really become an issue when the structural integrity of the boards is already compromised, which, as we mentioned, can happen when moisture gets into the boards. With this in mind, in humid or snowy areas like Colorado I tend to favor composites that contain bamboo, as opposed to those that contain sawdust. While wood easily absorbs water, bamboo is relatively hydrophobic, taking on very little moisture.

Choosing Decking for the Centennial State

The climate changes and temperature swings of Colorado are legendary. Dealing with all of this in one place makes carrying out deck maintenance in Colorado much tougher than it is in more temperate states. Having a deck here either requires a lot of work to keep it in good shape or a decking material that doesn’t require a lot of work.
If you have the time, the energy, and the money to keep up a wooden deck, it can be a rewarding labor of love. But, if you’re interested in directing those resources into other activities, then I’d advise choosing an option that’s light on maintenance and durable in any temperature or climate extreme. For that, moisture- and UV-resistant fully capped co-extruded bamboo composite decking by Fortress Deck is an excellent choice. Contact Fortress Deck to ask about their Infinity Decking, or visit Fortress Building Products to learn more about their family of companies making innovative building products.

Leave a Comment