Building Decks at High Altitude: Tips & Best Practices

Building a deck in Colorado's mountains requires careful consideration of materials, fasteners, and construction techniques. The combination of intense UV radiation, wide temperature swings, heavy snow loads, and low humidity creates conditions that can quickly deteriorate improperly built decks.

Choosing the Right Decking Material

Material selection is perhaps the most important decision you'll make. Composite decking has become increasingly popular at high altitude because it resists UV fading, doesn't splinter, and requires minimal maintenance. Leading brands offer 25-year or longer warranties and come in a variety of colors and textures that mimic natural wood.

For those who prefer the look and feel of natural wood, Western Red Cedar offers natural rot resistance and beautiful grain patterns. Redwood is another premium option. Both require regular sealing or staining — plan on every 1-2 years at high altitude due to the intense sun.

Pressure-treated lumber is the most economical option for deck framing and is required by code for structural components in ground contact. It's important to let pressure-treated lumber dry for 2-4 weeks before staining at altitude, as the dry air accelerates moisture loss.

Fasteners and Hardware

Fasteners matter more than you might think at high altitude. The dry air accelerates corrosion on standard fasteners, especially when combined with the chemicals in pressure-treated lumber. We recommend stainless steel or coated deck screws specifically designed for the decking material you've chosen.

Hidden fastener systems provide a clean, screw-free surface while reducing water infiltration through the deck boards. They're especially worthwhile with composite and hardwood decking materials.

Structural Considerations for Snow Country

Snow load is a critical factor in structural design. Colorado building codes require decks to support significant snow loads — often 40-80 pounds per square foot depending on your location and elevation. This means larger joists, closer joist spacing, and more robust beam and post connections than you might use at lower elevations.

Always consult your local building department for specific snow load requirements and consider working with a structural engineer for elevated or multi-level decks. Proper footings that extend below the frost line (typically 36-48 inches in mountain areas) are essential to prevent heaving.

Get the Right Materials

Stop by Rocky Mountain Building Solutions for a complete selection of decking materials, fasteners, and accessories suited to high-altitude construction. Our experienced staff can help you plan your project and select materials that will perform for years in Colorado's demanding mountain climate.