Stair Design & Construction

Stair Design and Construction for a Safe Climb

Stair Safety –  Stair Solution knows that your interior or exterior stairs are an integral part of the architecture for any home. As a day-to-day utilitarian item, stairs are a wonderful way to choreograph movement through a home and stair safety should be considered early in the process.

Stair Design & ConstructionIn all of a stair’s beauty, choreography and craft are elements that combine structure and material — all set to a required geometry to ensure that stairs are both a joy to traverse and safe. Some things are no longer allowed, such as risers that are too steep, treads that are too narrow, uneven riser heights and tread depths, and more. Let’s look at some of the considerations that go into the design and construction of a simple, straight-run stair.

A straight-run stair is just that: a stair that doesn’t turn or curve or something else. It just simply travels in a straight line from a lower floor to an upper floor.

Though we’ll be looking in detail at a closed-riser stair, this stair has open risers. Some building departments don’t allow such a stair design, as there’s a fear that small children may slip between the treads and fall.

What’s interesting in this stair is that the open risers are kept narrow, 4 inches or less, to comply with the local building code and still be open.

Get the angle right. The first thing we’ll do is set up the geometry for our new stair. We’ll divide the total rise (the distance from the first floor to the second floor) into equal parts, with each part not more than 7¾ inches (the maximum height allowable per the International Residential Code, or IRC).

Next we’ll want to establish the overall length of the stair, also called the carriage or total run. In our example that will be 140 inches. Now we know that we need a space that’s at least 36 inches wide (a minimum code requirement) by 140 inches long (plus landings at the top and bottom) for the stair. We also know that the angle of the stair won’t be too shallow or too steep, so it will be comfortable to walk up and down.

Stair Design & ConstructionFitting our feet. Looking in detail at how our stair lays out, the geometry of the treads (horizontal walking surfaces) and risers (vertical pieces at the back of each tread) is set. Be aware that each tread is 10 inches deep, there’s a 1-inch nosing that provides an overall depth of 11 inches. For overall stair safety, this is a comfortable dimension for most people, as it provides a suitable landing spot for most feet. Take a look at some of the beautiful finishes we have available.

Supporting our weight. Now that we’ve gotten our geometry set and know we comply with the building codes, we can start to build our stair.Stair Design & Construction

First come the stringers. These are the sawtooth sides of the stair to which the treads and risers will attach. While a stringer can be made of just about any material (wood, steel, aluminum, glass, plastic etc.), typically in residential construction, it is made of wood. By simply taking a solid piece of wood and then cutting out the teeth, we’ll have the basic structure of our stair.

Stringers are designed to be strong enough to support themselves and the weight of risers, treads and people. This allows a stair to “float” away from a wall if that’s the desired design. Of course, if the stringers aren’t designed to support all of the added weight of people etc., make sure they attach to an adjacent structural element.

Next come the treads and risers. Once these are in place, you’ll have a finished stair that can be used to go from one level to the next.Stair Design & Construction

An important design consideration is whether or not the treads and risers are to be visible surfaces or if these pieces will be covered with a finish (tile, stone, carpet etc.). For example, you can save some money by using utility-grade lumber for the treads and risers.

Preventing falls. While the stair is complete, you can’t make it down safely until there are railings. Stair Solution has many handrail options available. On the open side of the stair as well as at the second-floor landing, there should be a guardrail (not shown) that will prevent you from falling to the floor below.

Stair Solution specializes in residential and commercial handrail systems for interior or exterior. Residential Staircase makeovers include color and/or style change, decorative iron balusters or hardwood steps. Current trends reflect deeper richer color with modern lines such as box newels (post). Additional capabilities include custom fabrication of metal staircases (mono stringer) with horizontal stainless steel handrail systems or exterior, maintenance-free metal rail systems for decks, porches or entryways.Stair Design & Construction

Specifically, the rail can’t be more than 38 inches or less than 34 inches above a tread (or walking surface), and must be extended horizontally at the top and bottom.

Another code consideration for stair safety is the requirement to provide at least 80 inches of headroom above any walking surface. Just keep in mind that this, the height of a standard residential door, is the minimum; as such, I’ve always found it to be very constricting.