Building Deep and Wide Stairs

This project shows you how to add decorative trim to the edges of a deck.

Building Deep and Wide Stairs

Stair treads that are 14 inches wide make a graceful transition to the lawn and provide comfortable places for people to sit and relax.

Stairs with 14-inch runs (tread widths) should have rises of between 5-1/2 and 6-1/2 inches.

The wider the treads, the more total run the stringers have to span. When you notch stringers, you weaken them. After the notches are cut out of these 2x12 stringers, about 5-1/2 inches of uncut width is left for strength -- in other words, the stringers are as strong as 2x6s. These stringers have to span a distance of about 9 feet, which is close to the limit for a 2x6 joist. So 2x4 cleats were added for extra strength (Step 7).

Prestart Checklist

Most of a day to install a set of stairs like those shown

Tape measure, circular saw, handsaw, hammer, drill, framing square

Calculating rise and run for a stairway, measuring and cutting with a circular saw, fastening with nails or screws

2x12 for stringers, pavers, sand, and edging for the landing pad surface, decking for the treads, 2x4 toe-kick, lag screws with masonry anchors

Stairway Overview

Stringers are attached to a crossbrace at the top and a toe-kick at the bottom. The landing is made of concrete pavers set in a sand bed.

Step 1

Install a crossbrace directly beneath the joist to provide adequate surface for attaching the stringers. Connect the brace firmly to posts or the beam so it is just as strong as the joist above it.

Step 2

Calculate rise and run and mark a stringer using a framing square. Cut the top and bottom of the stringer and hold it in position to determine the location and height of the landing pad.

Step 3

To construct a paver landing pad, excavate the site. Install several inches of crushed limestone and tamp it firm. Install edging and check that the corners are square.

Step 4

Spread 1 or 2 inches of sand over the limestone and screed it with a straight board to form a level surface that is lower by one paver's thickness than the finished height of the pad.

Step 5

Set the pavers on top of the sand. If you need to cut any pavers, use a rented masonry saw. You may be able to avoid cutting pavers by adjusting the position of the edging. When the pavers are laid, sweep extra-fine sand into the joints; tamp firm and repeat.

Step 6

Cut the stringers. Notch the inside stringers for the toe-kick. Attach the stringers at the top to the crossbrace. Anchor the toe-kick to the pad using lag screws and masonry anchors.

Step 7

Attach the stringers to the toe-kick by toe-fastening with 3-inch deck screws. To add extra strength, attach a 2x4 cleat to the side of each stringer. For each step install the riser board first, then the tread boards. Clamp a scrap 2x4 to the side of an outside stringer to help maintain a consistent 1-1/2-inch overhang. For treads you can use two full-width decking boards and one board rip-cut to a narrower width.

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