For an outdoor staircase, the material must withstand freezing and thawing cycles, de-icing salt, and repeated impacts while still looking good over time. HDPE (high-density polyethylene) is one of the best-suited materials for these conditions. Naturally UV-stable, highly resistant to corrosion and abrasion, it does not degrade in sunlight, does not rust, and resists scratches better than most other outdoor surfaces.

• UV stability: The color does not fade, even after years in direct sunlight.
• Corrosion resistance: Impervious to salt and moisture.
• Abrasion resistance: Scratches are less visible than on most other surfaces.
• Through-color material: The color runs throughout the entire thickness, so scratches do not affect the appearance.

Dekavie HDPE stair treads are also resistant to mold, stains, and extreme temperature variations. With no paint or surface treatment required, there is nothing to maintain, and the clean appearance is naturally preserved, even after many years of heavy use and snow removal.

The depth of a stair tread directly affects comfort and safety in use. In Quebec, building code requires a minimum of 9.5 inches for an exterior step, but in practice, a deeper tread is always more comfortable and stable underfoot.

The 11.5-inch Dekavie stair board is the simplest solution: a single piece, no cuts required, and a depth that comfortably exceeds current standards.

If you prefer using two Dekavie tongue-and-groove boards, you will achieve a maximum depth of 11⅞ inches, depending on the width of your cut line to remove the visible tongue-and-groove edge.

The spacing between stringers depends on the material used. Thanks to their 1.5-inch thickness in solid plastic, Dekavie stair boards allow spacing of 18 to 20 inches between stringers.

If you choose Dekavie deck boards, it is recommended to space the stringers every 12 inches to ensure optimal stability.

No. Dekavie HDPE stair treads provide grip comparable to painted or stained wood, concrete, and other composite surfaces, which are commonly found on most outdoor staircases in Quebec. Under normal winter conditions, they are not more slippery than these alternatives.

Where HDPE really stands out is in its response to de-icing products. Salt does not damage the surface, does not corrode it, and leaves no marks, unlike wood, which swells and deteriorates, or concrete, which can chip and degrade over time.

A practical tip: if you install rubber anti-slip mats during winter, you will not have any unpleasant surprises in the spring.

You can use two Dekavie tongue-and-groove boards to form a step (see example in the photos above). It is also possible to choose our stair boards, designed specifically to simplify construction in a single piece, without complex assembly.

It’s the small details that make all the difference. Here are three key points to keep in mind:

Use fascia boards for the stair risers. This is the simplest way to transform the appearance of a staircase: fascia hides the stringers and instantly creates a clean, professional look.

Avoid angled cuts. In Quebec, temperature variations are extreme and all materials move accordingly. HDPE expands more in length than other materials, which means poorly executed angles can shift over time and compromise both durability and final appearance. The golden rule: keep it simple. Straight cuts are always more reliable in the long term.

Hide the screws. Use color-matched finishing plugs, or even better, fasten your treads from underneath for a truly flawless result. This way: no visible screws, no visual compromise.