Abrasive Strip Inserts in a Terrazzo Tread

There are two recommended methods endorsed by the NTMA (National Terrazzo and Mosaic Association) to create a safe stair tread.

Option 1: It is a trade practice to employ metal U channels at the stair nosing to create a non slip surface. The channels are anchored to the underbed similar to placing normal strip dividers. Prior to placing the terrazzo composition, these channels are filled with a backer rod material to prevent the composition from penetrating these lines. Once the terrazzo has been installed and completely ground, grouted and polished, the temporary fill of the channels is removed. One or two layers of masking tape (depending upon the elevation of the insert requirements) are placed to outline the channel lines. An epoxy and fine hard aggregate (normally black Alundum) is placed into the channels and tooled to the elevation of the masking tape. The tape is removed immediately prior to the epoxy curing.

Option 2: Complete the installation of the terrazzo including grinding and polishing process. Saw cut a straight void a minimum of 1/4" depth and a minimum of 3/8" width where the slip resistant strips are to be located. Apply masking tape and fill the saw cuts, as described above.