Pisa is the most versatile residential and commercial retaining wall block on the market today. Use Pisa to construct projects from low walls to high walls.
Applications – Design and build projects such as planters, steps, grill islands, pillars, seat walls and water features. Can be used for straight and curved installations (Radius 5’ is the tightest radius).
Capacity – Gravity walls up to 39” (1m). Geogrid reinforced walls up to 20 ft. (6.1m).
Recommended Base Stabilization – one layer of DriveGrid™ stabilization grid between subgrade and base material. Use under Standard Base or Permeable Base.
Standard Base – Min. 6” – 8” of ¾” Crusher Run gravel (any road base standard in accordance with ASTM-D2940) compacted to 98% Standard Proctor Density (SPD).
Alternative Permeable Base – Min. 6” – 8” of ¾“ clear open-graded stone compacted to achieve full particle lock-up and consolidation. (Clear open-graded does not compact but does consolidate slightly by rattling the particles together.)
Leveling – Leveling retaining wall blocks directly on top of gravel is tedious and generally does not yield the best results. U-Grip Base units or universal base pads are recommended under all Unilock walls for improved accuracy and speedier installation. Additional benefits include long term structural integrity and an overall better appearance. Poured concrete leveling pads, reinforced with rebar, are also a great way to accomplish leveling, particularly for larger installations. You must ensure that the concrete is poured and finished perfectly in order to achieve a good visual appearance.
Connection – features a tongue and groove connection. Use appropriate concrete adhesive for connection between units where the key has been removed or for corners. Always read adhesive manufacturers’ directions prior to gluing.
Handling – No specific handling instructions.
Coping - This wall requires coping. Choose a manufactured coping such as Unilock Universal Coping or any of our natural stone coping options. Install with tight joints or 3/16” gap between units and amend with an exterior latex caulking. Cutting may be required; a diamond blade saw is required to cut coping properly. Glue all coping using a specially formulated concrete adhesive that is strong and will not break down over time. Always read adhesive manufacturers’ directions prior to gluing.