Stair treads and risers are made to withstand some of the most abusive traffic known to our industry. Since they are so tough, cutting stair treads is very difficult and must be handled carefully. Extra care must be taken not to allow the cutting instrument to slip and cause an injury.

Stair tread types and preparation. There are two types of stair treads: the two-piece individual tread with separate riser, and the combination tread and riser (Photo 1). The preparation of the stairs must be done with the utmost care. Since the treads are subjected to a severe amount of traffic, it is important to achieve a good bond. Note that the nose of the tread has a slight rounding to help stop severe stress to the nose of the tread (Photo 2).

Two-Piece Tread and Riser

Scribing technique for the tread. Place a scrap of material flat on the tread of the step. Set a pair of dividers for the distance between the underside of the tread nosing and the front of the stair nosing (Photo 3). The scriber should be set to allow a slight gap at the juncture of the tread and riser, which will be covered by the toe of the riser.

Preparing the stair tread. After the scrap is removed from the back of the stair tread, at the juncture of the tread and riser, place the stair tread in position to scribe the left side of the tread (Photo 4). When cutting the salvage off the tread, place a slight bevel on the edge of the material to allow for a net fit.

Establishing position marks on the tread. Using a piece of masking tape, place a position mark on the stair tread and the riser (Photo 5). This will allow the tread to correctly scribe fit on the right side of the stairs.

Setting the dividers to scribe the right side. Move the stair tread until it is flat on the right side of the step. Set your dividers to allow for the distance moved (Photo 6).

Scribing technique for the riser. Cut the riser down to the height. Then place the riser up and scribe the left side of the riser, and set into place (Photo 7).

Placing the position marks on the riser. As with the stair tread, scribe fitting the right side of the riser requires the use of positioning marks in the same way as the stair tread scribing technique (Photo 8).


One-Piece Tread and Riser

Fitting the one-piece tread and riser. Many manufacturers make a one-piece tread and riser. Fitting both the tread and riser at the same time requires a lot of handling skill. To start, the material must be cut to height by using a scrap of tread and riser and establishing the amount to be trimmed off from the top of the riser. Once trimmed to height, the tread and riser is ready to be scribed. Set the tread into place and force the nose of the tread tightly to the nosing of the step. Failure to keep the nosing tight will result in a crooked fit  (Photo 9).

Establishing positioning marks to complete the scribe on the right side. Unlike with the flat stair tread, the positioning marks must be placed on the nosing of the stair tread (Photo 10). In all cases the nose of the stair tread must be kept tight to the nosing of the step.


Adhering the Tread and/or Riser

Applying nosing adhesive. Many manufacturers recommend the use of an epoxy at the nose of the tread. This is done by using a tube of stair nosing adhesive with a mixer nozzle. Place an even bead of stair nosing epoxy on the under side of the stair tread (Photo 11). Check the manufacturer’s recommendation for the amount of adhesive to be applied.

Applying tread adhesive and/or tape. There are several methods of adhering the stair tread to the tread of the step. Check with the manufacturer to be sure you are using the proper adhesive. Some will recommend a special contact adhesive while others will recommend a trowelable stair tread adhesive. The latest method is the use of a double-faced stair tread tape, which can be used for both the stair tread and riser (Photo 12).

The completed stairs. Stair treads are time-consuming and challenging, but the finished product will be a work of art.  Done properly the stairs are able to withstand a tremendous amount of heavy abusive traffic, without any problems. If you can install stairs without any major issues, you are well on your way to becoming an expert installer.