How to Build Outdoor Stairs

Constructing a staircase is a daunting project, but so long as you have the proper knowledge, you can build an outdoor staircase with ease. This article will help you become familiar with the vocabulary, design process, and construction of outdoor staircases.

Always check your local zoning codes before beginning the project.

Stair Vocabulary

When you are planning to build stairs, you must first know the total run, which is the measurement of the horizontal distance from the beginning of the lowest step to the edge of the upper landing.

You will want to refer to the measurements for each individual stair.

The ideal slope is 30-35 degrees. As a rule of thumb, if you use a 7-inch rise and 11-inch run for each step, that slope should be simple to maintain. Most codes require a 3-foot passage width, but you can make them wider.

The parts of the stairs you walk on are called treads, while risers take their name from the "rise" measurement.

All staircases have the same primary parts. Stringers are the slanted parts that provide support to the structure. Use either 2x10-inch or 2x12-inch lumber to build the stringers. Stringers must be spaced at a maximum of 24 inches, though with thicker lumber you can space them up to 36 inches apart.

Designing Outdoor Stairs

The first measurement you must take is the total rise. Divide that total by seven to determine the best height for each riser, and round to the nearest whole number. Divide the total rise by that number and round the dividend up to reach the final rise per stair.

To calculate how much material you need to purchase, factor the number of risers needed by the passage width (risers). Subtract the number of risers by one and multiply the difference by the passage width for the tread.

The measurement for the stringers is determined by factoring the total run by the passage width, then finding the product of the total rise factored by itself. The square root of the total rise equals the stringer length. Round up and multiply by the number of stringers needed to calculate the supplies.

This may sound complex, but it's just simple multiplication. Keep a pad and pencil with you to jot down measurements and do your calculations as you plan and design. A calculator also never hurts to limit the possibility of human error.

Building Your Stairs

Notch the Stringers

The first step is to notch the stringer material so that not only the treads but also the risers can be built into them. Use a carpenter's square and stair gauges to do so. Secure the stringer to the lower landing with a bolt.

Once the stringer is set, use a circular saw to cut out the notches, but do not cut them all the way. Once you have started the cuts with a circular saw, finish them with a hand saw and set the stringer.

Be sure to wear the proper safety gear including eye protection, and follow all manufacturer instructions when operating a circular saw.

Construct the Risers

Hang the stringers using your choice of either a rim joist or a joist hanger. Add a concrete slab for the landing if that is part of your design. Secure the stringers with 8d galvanized nails. Next, find the distance between the riser's face to the edge of the notch and cut the treads so that they extend slightly.

Add the Railing

Once the risers have been constructed, you can begin building the rail by securing 4x4-inch lumber for posts, then cut notches into the posts and attach them to the stringers. Then add the posts.

Once you've built the posts, add the top rail and toenail it with 8d galvanized nails.