Optimize Your Stair Stringers for a Safe Composite Deck
Technical note: Installation details vary by municipality, product line, board profile, fastening system, loads, and site conditions. Use this article as general guidance only; confirm the final design with your local building department, the manufacturer's current installation guide, and a qualified contractor or engineer when structural loads are involved.
Stair stringers form the essential framework of any composite deck. Precise cutting ensures stability, safety, and durability. Follow this guide to prepare, mark, and cut your stair stringers in Quebec, using premium materials like Fiberon, TimberTech, Trex, and TruNorth.
Essential Tools and Materials
- Clamps: to stabilize your 2x12s
- Circular saw: for initial straight cuts
- Jigsaw: for clean finishes
- Framing square and stair gauge: for marking risers and treads
- Drill and hammer: for adjustments and pre-drilling
Stringer Preparation
Use quality pressure-treated 2x12s. If a stringer rests directly on the ground, choose wood with a water retention rate of ≥ 0.60 RET. Place the wood's "crown" facing the cut side to minimize warping.
Place your 2x12 on sawhorses. Align the framing square and stair gauge according to the riser height and tread depth values obtained from our stair calculator. Mark the outline of the steps along the entire stringer.
For the last stringer, plan for an adjustment: the first step on the ground requires subtracting the thickness of a stair board. If you are installing a 1" riser, subtract it from the top stringer for perfect alignment.
Tips Before Cutting
- Always wear safety glasses
- Ensure the throat depth is at least 5”
- Respect the spacing recommended by your composite decking manufacturer
Stringer Installation
Load Requirements and Spacing
- Do not use a universal stringer spacing. Check the stair-span table for the selected board; many composite stair treads require support closer than 16" O.C., often 9" to 12" O.C.
- For wider stairs, add intermediate stringers as required by the board's stair-span table and the approved stair design
- A 48" wide stair may need several stringers; calculate the count from the exact board profile rather than a fixed rule
- Height and landings: confirm riser limits, required landings, and clearances with local code and the approved plan
Composite Materials and Specifics
- Some Fiberon or Trex boards require 10" spacing
- Always follow the manufacturer's installation instructions (TimberTech, TruNorth, etc.)
- Monitor the load from descending foot traffic
Calculating Total Height
- Measure the distance between the top of the deck and the ground
- Use our stair calculator to determine the number of steps
- Transfer the rise & run values to your square
Cutting the Stringers
Initial Cutting
First, make rough cuts using the circular saw, following your lines. Be careful not to overcut.
Finishing Cuts
For clean cuts, finish with the jigsaw or a hand saw. This preserves the stringer's strength.
Stringer Reproduction
Use your first stringer as a template to mark and cut the subsequent ones. This ensures the uniformity of your outdoor living space.
"Precision in cutting stringers ensures the safety and aesthetics of your composite deck." - Magasin de Patio Expert
Ready for Installation
Do you want a perfectly executed deck or deck in Quebec? Our outdoor living specialists are here to advise you and install your stair stringers safely. Contact us for a custom solution with Fiberon, TimberTech, Trex, or TruNorth.