Exterior stairs user guide
These examples show ways to build exterior grade stairs with pressure treated Ply-Lam stringers. Dimensions are guidelines only; the examples are not a complete engineered design. Always follow appropriate engineering practice and building code requirements.
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Unsupported lengths
The thickness (W) and effective depth (ED) of the stringer are adjusted to suit the required unsupported length. Lengths are those permitted by the Alberta Building Code.
| Product code | Thickness (W) | Effective depth (ED) | AB code permitted unsupported length | Recommended maximum steps |
|---|---|---|---|---|
| PT PL4 C 4.625 | 1.5 | 4.625 | 80 | 6 |
| PT PL4 C 8.625 | 1.5 | 8.625 | 148 | 11 |
| PT PL8 C 4.625 | 3 | 4.625 | 101 | 8 |
| PT PL8 C 8.625 | 3 | 8.625 | 188 | 15 |
Building the stairs
Step 1
Step 2
Recommended stringer spacing
Tread and riser options
Option 1: open riser
Option 2: open riser
Option 3: closed riser
