Photos 1A and B are of the stairwell; it looks like every other stairwell we've all walked up and down, right? Photos 2A and B are close-ups of the area of complaint. Cracks are appearing just in from the nose of the tread. These cracks run along the entire edge of the tread from left to right and are 3/4 of an inch deep/wide. The end users feel the stair treads are defective because it is happening in three different buildings all using the same treads. The installer feels the treads are defective as well, for the same reasons the end user does. Do the photos give enough information?
I should tell you that the adhesive used was two-part epoxy and the treads are rubber. And as most all manufactures recommend there was epoxy nose filler used on the inside of the nosing.
Now look at Photo 3A; this is one tread with the nosing edge pulled up and you are looking into the adhesive bed. What do you see or not see? Adhesive transfer is one shortcoming; also visible is the failure of the nose filler, right? Wrong; there is little if any transfer of the field epoxy so we have to ask why.
Rubber stair treads are molded product;s because of this you must remove the mold release agent (compound) prior to the installation. All manufacturers put flyers in the cartons and underline this step in their installation instructions.
Photo 3B shows the epoxy nose filler a little better, but what you do see is a lot of contamination in the bead of filler.
Photos 4A and B also show the nose filler at its worst. In Photo 4A we see no deformation of the filler bead, which means what? It means that the nosing was not adequately filled with the epoxy, as it should have been. Without the void between the stair pan and stair tread nosing full/filled it leaves a gap that will eventually cause the type failure you see here.
Photo 4B shows the nosing filler conforming to the surface of the stair step in only a small area, not the entire stair tread, as it should be. This photo also shows the contamination of the epoxy nose filler due to the lack of proper cleaning of the existing stair nose and tread prior to installation of the new treads. Thanks again for reading "You Make the Call." Have a great day!