FAQ

Footing requirements can vary by project. But typically a wall footing in ideal site conditions will consist of compacted dense-graded aggregate, will be a minimum of six inches thick, will extend beyond the front of the block by at least six inches and will extend beyond the back of the block by at least twelve inches. For specific details, download our Technical Guide.

Minimum base requirements are covered in question #1. Backfill requirements can vary by project. But under ideal site conditions, typical backfill will consist of clean, angular aggregate, in accordance with ASTM #57 standards. This aggregate will extend a minimum of twelve inches behind the wall, and will be separated from the retained soil by a non-woven geotextile fabric. For specific details, download our Technical Guide.

There are freestanding versions of every HIGH FORMAT wall. In fact, all standard HIGH FORMAT wall products except Rosetta Outcropping can be used in both freestanding and retaining walls.

Your local HIGH FORMAT distributor will be happy to supply a list of amazing contractors, landscape architects and engineers in your area. See the HIGH FORMAT dealer map.

Geogrid is an engineered geotextile that is used to stabilize the retained soil behind a retaining wall, allowing for taller walls. Any wall tall enough to require geogrid should be designed by a registered geotechnical or structural engineer.

You should always design proper drainage into your wall. Trapped water is the cause of nearly every retaining wall failure. In addition to the backfill guidelines listed in question #3, a minimum four inch diameter perforated drain tile should be placed in the lowest free-draining location behind the wall. For complete details, download our Technical Guide.

We provide preliminary height guidelines for all HIGH FORMAT wall systems. These preliminary guidelines are for reference only, and are not intended for final construction. Any retaining wall requiring soil reinforcement should be designed by a registered geotechnical or structural engineer. Also, the International Building Code calls for building permits to be acquired for any retaining wall to be built above four feet tall. Some local municipalities have more stringent guidelines. See each product page for guidelines.