2 tips to build outdoor stairs

There's so much to know about building your deck that it's possible to overlook other considerations. But the stairs are essential, and you want them to be as safe and as durable as possible. Here are a couple of tips.

• There are two ways you can configure the stringer boards that support the treads of your outdoor stairs.
• In an open design, the stringers are cut out to receive the treads (and the risers, if you are using them).
• Although it is more difficult to build, the joint is protected from water buildup and will last longer.
• In a closed design, the treads fit between the stringers, sitting on a cleat or metal support attached to the inside of the stringers.
• Closed stringers provide a more finished look, but water will seep into the joints between the treads and the stringers, making the treads vulnerable to rot.
• If you do opt for closed stringers, use metal support hardware instead of wooden cleats.
• The cleats, hidden from the drying effects of the sun, will be even more vulnerable to rot than the treads.
• Also, it's best not to support the treads in dadoes (grooves) cut into the stringers. That's excellent indoor construction but a sure recipe for rot outdoors.

• Vertical riser boards placed between each step do provide a finished look. But on outdoor steps, the joint where risers butt the tread below always collects rot-inducing moisture and debris.
• There is no structural need for riser boards, so consider eliminating them if you are building or restoring an outdoor stair.
• If you do include risers, leave at least 1 centimetre (1/2 inch) of space between the bottom of the riser and the tread.