How Thick Should Stair Treads Be?

There's a lot of guidance available regarding the correct run, rise, and stringers required for stairs. However, once stairs are built, these things are pretty firmly established. If you plan to replace or cover your current stair treads, you might be wondering - how thick should stair treads be? A thorough look at IBC building codes means this article has everything you need to know about stair treads.

Wood is the most common stair tread and must be at least one-inch thick on stairs supported by risers. Wood must be at least one-and-a-half inches thick when used with open risers. Building code states that stair treads must be thick enough to support a person going up or down the stairs. Stair treads can be made of many different materials, such as steel, concrete, or wood. The correct thickness will vary depending on the material.

Keep reading to learn more about what material you can use for treads, why treads available in stores don't always seem to meet code, how you can stylize your treads, and what to do if your current stair treads are not thick enough.

A modern light oak, straight wooden staircase balustrades, How Thick Should Stair Treads Be?

How Do You Figure Out Stair Treads?

There isn't one set answer as to how thick stair treads must be. The required thickness will change, depending on what material is used. There is also no set maximum, although there is such a thing as too thick treads. Stair treads that are too thick can cause trips and falls. If you use thick treads, avoid stair nosing (which is the most likely cause of a fall).

Building codes do not dictate a specific limit on the thickness of the stair tread. However, codes do state that stair risers cannot be more than seven-and-a-half inches, including the stair tread.

Thicker treads do have benefits - they are more durable, and they are less likely to squeak. As a general rule, the more stairway stringers you use, the thinner the treads can be (as long as you still meet building codes). Conversely, if you use thicker treads, this will allow you to use fewer stringers.

Less than one-inch stair treads - How Can That Be?

If you're looking at stair treads, you may find ones that are less than one-inch. Usually, they are made of vinyl or laminate, and sometimes wood. But how can they sell stair treads that are against building codes?

Typically, you install these treads by gluing or caulking them down on top of an existing stair tread. They offer an appealing cover to unattractive treads, but installation has to be over one-inch plywood already in place. If you read the manufacturers' instructions carefully, you can see these treads are not made for use alone.

Secondly, the one-inch measurement occurs at the nose of the stairs. Stairs can have a stair nose that is at least one-inch thick, while the rest of the tread may be less. Most nosing intends to be thicker and hang over the stair rise, which is part of the desired look.

Materials For Stair Treads

Stainless Steel

Stainless steel won't rust, and it's durable. Maybe most importantly, stainless steel has lots of style options. You can buff, powder-coat, or paint steel to get the desired look. Another possibility is to apply a finish, such as a patina. Because of steel's strength, it doesn't require a thick tread (only about 3/16 of an inch). Stainless steel isn't used often in homes, but you see it frequently in commercial settings because of how tough it is, especially in high traffic areas.

Glass

For stairs, glass has a unique and one-of-a-kind look. It is expensive, but it also lasts for a long time. Glass isn't damaged by water like wood can be. However, scratches do happen. Avoid glass for high traffic stairs where damage is likely to occur (such as by pets or kids).

Stone

Attractive options like granite and marble make for a stand-out staircase. Stone is expensive, but, like glass, it will last for years. The biggest downside to stone is the maintenance. To begin with, stone requires sealing every year. For an easier option that's less work, consider quartz (which doesn't need to be sealed or waxed).

Wood

A high maintenance option that also requires sealing, wood can last for a long time when properly cared for. Wood can be slippery, so you'll want to be sure to address fall risks. Some kind of non-skid addition, such as these non-slip strips (transparent, so they don't detract from the beauty of your stairs) will take care of the problem.

Click here to see these non-slip stair treads on Amazon.

What Type of Wood Is Used For Stair Treads?

On uncarpeted stairs, most wood installations are hardwood. It's classic, attractive, and wood stains are available to match the stair color to the rest of the home's flooring. If your home decor uses warm wood tones, try cherry, mahogany, or hickory. To complement cool wood tones, use ash, maple, poplar, or pine. You can read more about wood tones here: Should Wood Floors Be Lighter Or Darker Than Cabinets?

If you aren't trying to match a specific type of wood, oak is a versatile choice that works in almost any design. It's affordable, durable, and looks nice even when it's left unfinished.

Can You Use Plywood For Stair Treads?

Plywood makes a great cost-effective option for stair treads. It's durable and easy to work with, plus it can be painted or stained to fit almost any decorating style. Plywood will follow the same rules as any other wooden stair treads - at least one-inch thick (one-and-a-half inches thick when used on open riser stairs).

Carpet covers plywood in most cases, but it doesn't have to. You can read more about Should Stairs Be Carpeted Or Wood? Then, if you choose to paint or stain rather than carpet the stairs, just follow the steps here: How to Paint or Stain Plywood Stairs? [4 Steps]

How Thick Should Concrete Stair Treads Be?

Concrete is a little different than other stairs. Because of how it is poured, the entire stair is made of the same concrete (the run and rise). Since it's all part of an entire set of steps, there really isn't a separate stair tread that can be measured for thickness.

However, like any stair, concrete needs to follow the same building codes. This means that each step should be 11-inches deep. Stairs can technically be only ten-inches if they have a stair nosing. This is very difficult to add to concrete steps. It's easier to go with 11-inches and skip the nosing. The rise can be no less than four-inches and no more than seven-and-a-half inches high.

How To Fix Thin Stair Treads?

If you don't think your stairs are up to code, let's consider the options. While there is no maximum thickness specified for the tread, it can't be so thick that it pushes the stair rise out of the maximum seven-and-a-half inches allowed by code.

If you believe that your stair tread does not meet the minimum one-inch thickness, there are only a few ways to correct it. If the stairs are only slightly off, you may be able to find a stair tread that you can glue down over the current stair. The combined thickness of both may be enough to meet the requirement.

Click here to see this red oak stair tread on Amazon.

Note that you can not use a material like carpeting to increase the thickness. According to code, this is an aesthetic improvement that does not offer stability to the stairs. For this reason, do not include carpeting when measuring your stair tread thickness.

If the problem can't be solved that way, the only alternative is to remove all of the stair treads. Then, replace them with something thicker that meets building codes. Hopefully, you'll be able to replace the treads without exceeding the maximum height of seven-and-a-half inches on the riser. Otherwise, you'll have to rebuild the riser on the stairs as well.

In Conclusion

Stair treads made out of wood must be at least one-inch thick or one-and-a-half inches thick on open (floating) staircases. Stair treads made out of other materials, such as stone, concrete, glass, or steel, may not have to be as thick. They will still have to meet other building codes such as a stair run of at least ten-inches and a rise that is no less than four-inches and no more than seven-and-a-half inches. If you need to fix stairs that have a tread that is too thin, you may be able to glue a stair tread over a plywood stair base. Otherwise, you will have to reinstall treads that are the correct thickness.