Trex Stairs: The Ultimate Guide to Building Like a Pro

Trex Stairs: The Ultimate Guide to Building Like a Pro

This guide provides comprehensive instructions for building stairs with Trex, a popular composite decking material known for its durability and low maintenance. We’ll break down the process into manageable steps, covering everything from planning and preparation to installation and finishing touches.

1. Planning and Preparation: Laying the Foundation for Success

Before you begin physically building stairs with Trex, careful planning is crucial. Accurate measurements, proper material selection, and understanding local building codes will save you time and prevent costly errors.

1.1. Measuring and Calculating Stair Dimensions

Getting the dimensions right is the most important step when building stairs with Trex. Use a builder’s level and measuring tape for accurate readings.

• Total Rise: Measure the total vertical distance from the upper landing to the lower landing.
• Total Run: Measure the total horizontal distance covered by the staircase.
• Number of Risers: Divide the total rise by the desired riser height (typically 7-8 inches). Round up to the nearest whole number. This determines the number of steps.
• Individual Riser Height: Divide the total rise by the number of risers.
• Individual Tread Depth: Divide the total run by the number of risers minus one. Aim for a tread depth of 10-12 inches.

1.2. Understanding Building Codes and Permits

Stair construction is governed by local building codes. Contact your local building department to obtain necessary permits and ensure your design meets regulations. Key areas of focus include:

• Riser Height and Tread Depth: Code specifies acceptable ranges for these dimensions to ensure safe and comfortable use.
• Handrail Requirements: Handrails are typically required for stairs with four or more risers. Height and grip diameter are usually specified.
• Guardrail Requirements: If the stairs lead to a raised platform or deck, guardrails may be required to prevent falls.

1.3. Material Selection: Choosing the Right Trex and Framing

Select appropriate Trex decking boards for the treads and risers. Choose pressure-treated lumber for the stringers and framing, ensuring it is rated for ground contact.

• Trex Decking Boards: Select a Trex product suitable for stair treads. Consider the board’s thickness, width, and slip resistance.
• Pressure-Treated Lumber: Use lumber rated for ground contact (e.g., ACQ-treated) for stringers, posts, and framing. Select appropriate lumber dimensions to handle the stair’s load.
• Fasteners: Use stainless steel or coated screws and nails designed for use with both pressure-treated lumber and composite decking.

2. Constructing the Stair Frame: Building the Foundation

The stair frame, primarily consisting of stringers, provides the structural support for the Trex treads and risers. Accurate cuts and secure assembly are essential for a safe and durable staircase.

2.1. Cutting the Stringers

Accurately cut the stair stringers according to the calculated riser height and tread depth. Use a stair gauge or framing square for precise layout.

1. Marking the Riser and Tread Lines: Use a stair gauge to mark the riser and tread lines on the stringer lumber.
2. Cutting the Stringer: Use a circular saw to cut along the marked lines. Be careful not to overcut.
3. Notching the Stringer: Finish the cuts with a handsaw or jigsaw to create clean notches.
4. Repeating for Multiple Stringers: Create at least three stringers for a standard staircase, more for wider stairs.

2.2. Assembling the Stair Frame

Securely attach the stringers to the upper and lower landings using appropriate fasteners. Add posts and framing to provide additional support and stability.

• Attaching to the Upper Landing: Use ledger board hangers and screws to attach the top of the stringers to the deck frame or landing.
• Attaching to the Lower Landing: Secure the bottom of the stringers to a concrete pad or ground contact lumber using appropriate anchors and fasteners.
• Adding Support Posts: If the staircase is high or requires extra support, add posts beneath the stringers.
• Framing for Additional Support: Frame between the stringers for extra rigidity, especially for wider stairs.

3. Installing Trex Treads and Risers: Adding the Finishing Touches

Once the frame is built, install the Trex treads and risers to create the finished stair surface. Proper spacing and secure fastening are key to a professional-looking result.

3.1. Installing the Risers

Attach the risers to the stringers using appropriate screws. Maintain consistent spacing between risers for a uniform appearance.

• Pre-Drilling: Pre-drill holes through the Trex risers to prevent splitting.
• Fastening: Use two screws per stringer to secure the riser.
• Spacing: Ensure consistent spacing between risers using shims or spacers.

3.2. Installing the Treads

Attach the treads to the stringers, overlapping the risers. Use hidden fastener systems or color-matched screws for a clean, professional look.

• Hidden Fastener Systems: Many Trex products are designed to use hidden fastener systems for a seamless appearance. Follow the manufacturer’s instructions.
• Face Fastening: If using screws, pre-drill and countersink the holes to create a flush surface. Use color-matched screws for a discreet appearance.
• Overhang: Ensure the treads overhang the risers slightly for a comfortable step.

3.3. Addressing Gaps and Alignment

Carefully check for gaps and misalignments. Use shims and trim boards to achieve a consistent and professional finish.

• Shimming: Use shims to level and align treads and risers.
• Trim Boards: Add trim boards to conceal any gaps or imperfections.
• Caulking: Use exterior-grade caulk to seal any remaining gaps and prevent water infiltration.

4. Adding Railings and Handrails: Ensuring Safety and Code Compliance

Install railings and handrails to provide safety and comply with building codes. Choose railing systems that complement the Trex decking and enhance the overall appearance of the stairs.

4.1. Railing Post Installation

Securely attach railing posts to the stair frame, ensuring they are plumb and spaced according to code requirements.

• Post Placement: Position posts at the top and bottom of the stairs, as well as at intermediate points if required by code.
• Attachment Methods: Use lag screws or through bolts to securely attach posts to the stringers and framing.
• Leveling and Plumb: Ensure the posts are plumb and level before attaching the railing sections.

4.2. Railing Section Installation

Install the railing sections between the posts, following the manufacturer’s instructions. Ensure the railings are securely attached and meet code requirements for height and spacing.

• Railing Types: Trex offers various railing systems that are designed to match their decking products.
• Attachment Hardware: Use appropriate brackets and fasteners to attach the railing sections to the posts.
• Code Compliance: Verify that the railing height and spacing meet local building codes.

4.3. Handrail Installation

Install the handrail along the stairs, providing a secure and comfortable grip. Ensure the handrail is at the correct height and extends beyond the top and bottom of the stairs.

• Handrail Height: The handrail height is typically between 34 and 38 inches above the stair tread.
• Handrail Extension: The handrail should extend at least 12 inches beyond the top and bottom risers.
• Attachment Methods: Use brackets and fasteners to securely attach the handrail to the posts or wall.

Alright, hopefully, you’re feeling confident about building stairs with Trex now. Go get ’em, and let us know how it goes!