Stair Treads and Risers for the Outdoor Deck

When planning a stairwell for your outdoor deck, stair treads and risers are something you will need to consider before you pull out the hammer and nails and start building. Not only will you need to know how to properly lay out the risers and treads, you will need to choose a material that is suitable for your outdoor deck and application. There are many choices when it comes to materials and you should know what riser and tread choices you have.

Waking Up to the Dangers of Pressure-Treated Lumber

Of all the materials used to build risers and treads on outdoor deck stairwells, pressure-treated lumber is still the most popular. It is easy to work with, resists water and rot damage fairly well and is relatively inexpensive. While these reasons would to seem to make pressure treated lumber the obvious material choice for your deck stairs, there are some things you really need to know about this type of wood before you rush out and buy a truck load.


During the treatment process, pressure-treated lumber is treated with heavy metal materials such as tin or copper. The heavy metal used in pressure-treated lumber is very effective at protecting the wood from may types of pests, disease and water or rot damage. However, the heavy metal present in the lumber cause other problems that endanger our environment. Most notably, the heavy metal used in the treatment process often seeps out of the pressure-treated lumber and finds its way into well or ground water. In some cases, the dangerous heavy metals even end up in the drinking supply.

The way heavy metals wind up in ground or well water is certainly not a mystery. When it rains, the water that flows over the pressure-treated lumber often carries away small metal particles that are in the wood. When the water eventually drains or seeps into the ground, heavy metals such as copper or tin are carried with it.

In addition to the potential water concerns posed by pressure-treated lumber, there is the fact that pressure-treated lumber requires cutting down trees that can take up to 40 years or more to replace. Oxygen creating by plants and trees is at an all-time low, and we can no longer afford to lose trees for use as deck stairs. 

Better Riser and Tread Alternatives

Instead of using pollution-causing pressure-treated lumber for your deck stairs, you should consider other more eco-friendly materials. For instance, there are many new plastic-wood substrates and renewable wood product options that make excellent materials for use as risers or treads in outdoor deck stairs. Plastic-wood materials do cost a few dollars more; however, they last longer; require less maintenance and don't negatively impact our environment nearly as much as pressure-treated lumber.

If you must use natural wood for your deck stair risers and treads, you should consider hardwood substitutes such as Bamboo. Bamboo is quickly renewable and makes a solid material for deck stairs. You will need to be sure to cover Bamboo with a protective polyurethane though, as it is not as resistant to water damage as pressure-treated lumber. However, with a tough clear coat protectant, it will hold up very well to the elements for many years.