Matching Garapa Decking to Deck Stairs

Understanding Garapa Decking for Stair Treads

Garapa (Apuleia leiocarpa), often referred to as Brazilian Ash, is a very durable hardwood with an air dry density of 4.11 lbs/bf. Its natural resistance to termites and weather changes makes it a robust choice for exterior applications, including deck stairs. Garapa is also noted for being scratch and slip resistant, with minimal splintering, which are favorable characteristics for walking surfaces.

When considering Garapa for stair treads, it's important to recognize that a single decking board may not meet the required tread depth or structural load for code compliance. Most decking boards are typically 5/4"x6" (actual 1" x 5.5"). Standard stair treads often require greater depth and thickness, or multiple boards secured together over appropriate stringer spacing.

Stair Design and Material Selection

Deck stairs typically consist of stringers, treads, and risers. Stringers are the angled structural supports that carry the load. Treads are the horizontal surfaces you step on, and risers are the vertical boards between treads. While Garapa decking boards are ideal for treads and risers due to their durability and appearance, the stringers are usually constructed from pressure-treated lumber or other structural materials.

For treads, common approaches include using a single wide board, two narrower boards, or a combination. If using multiple Garapa boards for a single tread, ensure they are securely fastened and supported to prevent movement or gaps. The choice of board width for treads should align with the desired aesthetic and the structural requirements for tread depth. Garapa is available in 5/4"x6" (1" x 5.5") profiles, which can be utilized individually or in combination. Grooved options are also available for hidden fastener systems on the deck surface, but face fastening is typically used for stair treads to ensure secure attachment.

Supporting Garapa Stair Treads

The structural support for your Garapa stair treads is critical for safety and longevity. Stringers must be adequately sized and spaced to support the anticipated load without excessive deflection. The span of the Garapa tread boards will dictate the maximum allowable spacing between stringers.

Garapa is resistant to nailing and screwing due to its density. Pre-drilling is recommended for all fasteners to prevent splitting and ensure a secure connection to the stringers. High-quality stainless steel fasteners are advised for their corrosion resistance in outdoor environments, preventing unsightly staining and ensuring long-term holding power.

Local Building Codes and Safety Considerations

Adhering to local building codes is paramount for any stair construction. These codes specify critical dimensions such as tread depth, riser height, handrail requirements, and stringer spacing. Typical residential codes might require a minimum tread depth of 10 inches and a maximum riser height of 7 3/4 inches, with consistent dimensions for all steps.

Before beginning construction, consult your local building department for specific requirements in your area. This includes obtaining necessary permits and ensuring your design meets all safety standards. For instance, open risers may have restrictions on the size of the opening to prevent small objects or feet from passing through. Handrails and guardrails are also essential safety features, and their design and attachment points should be planned in conjunction with your Garapa stairs.

Worked Example: Designing a Two-Board Garapa Tread

Let's consider a hypothetical stair design requiring a finished tread depth of 10.5 inches. Using Garapa 5/4"x6" (actual 1" x 5.5") decking boards, we can achieve this depth with two boards. The first board would be installed flush with the front edge of the stringer, providing 5.5 inches of depth. The second board would then be installed behind it, overlapping slightly to achieve the total 10.5-inch depth.

For a stair run with 5 steps, each with a 10.5-inch tread depth, and assuming a width of 36 inches, you would need to calculate the total linear footage of Garapa. Each step requires two 36-inch boards, totaling 72 inches (6 feet) per step. For 5 steps, this would be 30 linear feet of Garapa. Given that Garapa is available in lengths from 3 to 24 feet, you would purchase boards that minimize waste. For example, five 6-foot boards would provide exactly 30 linear feet. Remember to account for cut waste and any slight variations in length when ordering. Ensure adequate stringer support for the combined width of the two boards.

Before you order

• Verify local building codes for stair dimensions (tread depth, riser height, stringer spacing).
• Determine the desired finished tread depth and plan how Garapa boards will achieve it.
• Select appropriate structural materials for stringers (e.g., pressure-treated lumber).
• Calculate the linear footage of Garapa needed for treads and risers, accounting for cuts and waste.
• Choose a fastening method (pre-drilled stainless steel screws are recommended for Garapa).
• Plan for handrail and guardrail integration, if required by code or design.
• Confirm ventilation and drainage considerations for stair components.

Confirm installation details, approved uses and warranty terms in the current instructions for the exact product and profile. Your installer should verify the substrate, structure and applicable project requirements.

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