Hi Jeff,
Thank you for your question. Yes, one gal. will cover the job. Each gal. covers a total of 100sqft. Here are the installations: INSTALLATION OF RUBBER STAIR TREAD: After the steps have been prepared and the stair treads cut and fitted as described, begin installation by spreading adhesive on the stair step completely covering the surface and the nosing.
When using contact adhesive, the adhesive should then be spread on the bottom of the stair tread and completely underneath the nosing. Always follow instructions on label of adhesive container.

We suggest coating two steps and two treads at one time, and then install the treads, as described below. An alternative suggestion is to apply adhesive to every other step on a flight of stairs, install those treads; go back and do the remainder.
The most important factor in proper stair tread installation is to see that no air space exists underneath the nosing part of the tread. The tread must not flex or move as traffic walks across the steps. Epoxy Nose Caulk should be used as described on the label.
Thank you,
The Koffler Team