How to Avoid Problems When Installing Stair Treads
June 10, 2009
Stair treads have been around for a long time, and are a tough, durable and safe covering for stairs from heavy duty to light usage. Growing up in the industry, I always found stair treads an interesting material. I spent several years working for a major manufacturer of stair treads, and recently started working with another. You could say this is a product category that is near and dear to my heart. I recently visited an office where diamond design rubber stair treads were installed and asked how old they were. The answer, “1965,” did not surprise me. Done properly, stair treads will last a good long time.
The keys to stair tread installation success start before even taking the order. There are two types (rubber and vinyl), two shapes (round nose or square nose), two different constructions (one piece tread and riser or separate tread and riser), and a variety of surface textures (diamond, ribbed, circular, smooth, etc.). Rubber treads are the most widely used, for everything from the most heavy traffic area to light duty use. Vinyl treads tend to be for light duty use.
As for the type of nose, this is an important detail. “Square Nose” could be a 90-degree angle step or in the case of newer steps the riser is angled back to provide a more safe walking surface, as per the Americans with Disabilities Act (ADA). Make sure the tread can be angled. Some treads come out of the box already angled and some have a notch at the nose so it can be bent slightly, as shown in the photo below. I remember being on a job where square nose treads were ordered for an angled step. I had to show the installers how to grove out the back of the nosing by hand. We made it work and it turned out to be a beautiful job, but the extra time required could have been avoided by ordering a tread that was able to handle an angled riser.
Round nose treads also need some careful attention. Not all treads are able to wrap all the way around a typical round nose wooden step, so take an actual sample to the job to be sure.
In addition to making sure the tread itself will fit the steps, there are some variations in instructions among the different manufacturers, so check their book before you start.
Pay attention to all of the details before getting started because the last thing anyone wants is to be responsible for someone who trips down the stairs because of a loose tread.
Once the order is placed and the material comes in, proper handling of stair treads can prevent a lot of problems. Store flat to prevent any distortion - if the treads are bent or folded, they can become wavy and it will take a lot of effort to get them to lay flat. All materials and adhesive should be delivered to the job site two days in advance so they can acclimate to job site conditions, which should be 65 to 80 degrees Fahrenheit, just like any other resilient flooring material. In the winter, make it three days just to be sure.
Even on new steps, allow time to clean paint, Spackle, dirt or other material that can telegraph or interfere with adhesive bond. High spots should be carefully ground down - be sure to wear a mask to avoid breathing in the dust. Use a “dustless” grinder to keep yourself and everyone else on the job site safe. On wood steps, countersink all the nails and re-nail or replace loose treads or risers.
Use a very high quality patching compound to fill in any low spots in wood or concrete steps. Make sure to use a patch that is rated for heavy duty traffic, and mix it properly to assure it dries as hard as possible because steps take a pounding like no other floor covering.
When covering metal stairs, clean the surface by wire brush, sandblasting, or other mechanical methods, and then prime with the recommended primer, per the stair tread manufacturer. For ceramic or terrazzo stairs, sand thoroughly to remove any glazing and then fill grout with a heavy duty patching compound.
If there is an existing star tread or other resilient flooring on the steps, they must be removed. No manufacturers recommend this application.
The most important part of the preparation of a step is the nose itself – the very edge of the step where feet hit as people are walking. If this edge is damaged or wavy, this will be a point of weakness that will cause the tread to crack and might cause someone to trip. Epoxy nose filler can be used to take care of minor irregularities, but any major damage needs to be fixed before the treads are installed. If the tread cannot be installed with a relatively tight fit at the nose, don’t proceed with the installation.
Because there are different formulations of stair treads, compatibility of the tread material and the adhesive is best assured by using only the adhesive that is specified by the manufacturer. Depending on the use, the adhesive will be either a contact type that is applied with a brush, or a trowel-applied acrylic type adhesive. When applying acrylic adhesive, do no more than five steps at a time to prevent the adhesive from drying out or “skinning over” when you lay the treads in. Open time can be as short as 45 minutes, so this is important.
The last time I wrote about stair treads, the adhesive tape system was starting to be widely used and today it is even more popular because it allows the treads to be walked on more quickly than a wet adhesive does. This odorless reinforced adhesive tape system provides fast and permanent adhesion of stair treads, risers, and stringers. Regardless of the type of adhesive system – acrylic, contact or tape, go by the book and check with the manufacturer to decide which system is right for you and for the specific job you are doing.
Many stair tread installations require the use of epoxy nose filler, also called nose caulk, a filler used at the nose of the step to provide strength and prevent movement at that point by filling in voids between the edge of the step and the nose of the tread. Using epoxy nose caulk greatly reduces the chance of the tread cracking. The epoxy can be applied in either of two methods. One is to hand mix in the can, like any other epoxy, and knife the mix into the nose of the step just before setting it into the adhesive. This needs to be done carefully, because epoxy cures quickly so it may be wise to order one quart cans instead of gallons, even though the adhesive cost is slightly higher, to reduce waste.
Rather than mixing in cans, an easier method is to use epoxy in a dual cartridge caulking gun. There are some stair tread manufacturers do not require epoxy at the nose. This is a real time savings for the installer, but make sure that step is in good condition so you have a tight fit. There is no harm in using nose caulking on these products, so if there is any doubt, use it.
When installing treads, cut each tread to size before the adhesive is spread. Don’t assume that every step in the flight is the same size, so measure each step at the nosing and at the back of the step where it meets the riser. If installing one-piece tread and riser, use cove stick at the back of the step where the tread meets the riser.
On wide steps, seams may be required. If a patterned stair tread will have a seam, the treads need to be ordered as such with a left half and a right half so the pattern will match. Treads can be cut with a knife or a saw. After cutting, mark each tread so you know which tread goes on which step.
After cutting the treads, apply the adhesive or the tape according to manufacturer’s instructions and apply epoxy nose caulking right before the tread is set. Holds the tread up, set the nose first, then work your way back.
With the tape system, apply the epoxy nose filler, remove the release paper from the nosing, and set the tread against the step edge. Then fold the tread back carefully and remove the release paper from the back of the tread, working from the front of the tread to the back and press the tread onto the step. Whether you use tape or adhesive, a hand roller will make sure the tread makes contact with the adhesive. Clean up adhesive residue right away, especially epoxy, which cannot be removed once it cures.
Finally, pay attention to the detail at the top step as it will meet some other type of floor covering, so a smooth transition needs to be planned for; the top step may not be just another stair tread. Sometimes rubber nosing works better at the top step. Another option is where stair treads meet carpet, or it may be necessary to use some type of reducer molding. Some treads or nosing can butt to a 1/8” flooring material, or can be trimmed back for thicker floor coverings. This detail at the top step is important for aesthetic reasons and also to prevent a trip hazard. If rubber tile that matches the stair treads is used, it may be necessary to trim the stair tread to match the pattern up with the landing tile.
Some other finishing touches include matching stringers, which have to be fitted very carefully, sometimes by making a pattern of cardboard or paper.
Some manufacturers have a matching color acrylic caulk available that can be a nice way to fill any gaps in a stair tread installation.
Keep traffic off the stairwell for the recommended time period to prevent shifting of the treads if someone walks on the steps too soon after installation.
There is a lot of detail work required when specifying, estimating and installing stair treads. It’s not hard, but it is time consuming so take your time and don’t be afraid to call the manufacturer for help or advice. The end result is worth it because this floor covering is beautiful and provides a safe walking surface that will last for decades when installed and maintained correctly.