Pisa2/Roman Pisa - Risers are constructed using a Pisa2 or Roman Pisa Stretcher, a Full Cap and a coping unit for the tread, although you can choose to use Full Caps as the tread if desired. Depending on the style you use, you must then determine the height of the rise. Start by building corners, as described in the Corner Section, on each side of the stairs. To construct the side walls, we recommend using Full Caps to avoid the automatic step-back created by the tongue and groove molded into the Stretcher units. Lay all the courses in the side walls vertically, with no set-back. Be sure to bond the units together with SRW Adhesive. Backfill with 3/4" stone as you go up, and don’t forget to use filter fabric to keep the soil from infiltrating the stone. Once the side walls have been erected, you can start the stairs at the front or set them in from the corners. The depth of the excavation will depend on the height required for the risers and the coping style used. The height of the first riser should measure from the top of the tread (or Full Cap if a coping unit is not used) to the finished grade. Install and compact a 6" gravel base as the footing. Place a row of Stretchers onto the base and carefully level them front to back and side to side. Next, place the second course using Full Caps. Construct the next riser assembly by placing and compacting another 6" thick gravel footing behind the first course of units. Now position a row of Stretchers onto the base and position them directly behind the Full Caps in front. Complete the riser by placing Full Caps for the second course. Install successive risers in the same manner for the number of stairs needed.

Treads
Once the stair risers have been constructed, you will need to set the treads. Adhere the style coping unit you have selected with SRW Adhesive as instructed in Section 7 - Capping the Wall. Position the treads to provide a 1" overhang. Allow the adhesive to cure at least 24 hours before opening the stairs to traffic.