ROCK GABIONS

Gabions were developed as an inexpensive retaining wall system using 3” x 3” welded wire cages that can be filled with any sort of rock or inorganic material such as brick, block or concrete debris.

These cages are 18 inches wide x three feet tall x six feet long. This entire wall is 48 feet long and took four men a day and a half to grade, compact, layout, assemble and fill with a small loader. It’s located at the Tuck Shop Restaurant at 12th Street and Oak in Phoenix.


ROCK FENCES

This six foot tall x eight inch wide rock fence replaced a chain link property line fence. Its support posts are set in concrete and are designed to be almost entirely hidden when the rock is loaded into the welded wire fabric panels.

The fabric wire is about as thick as a pencil and has internal hooks that hold the panels to exactly eight inches apart. The temporary wood braces insure the whole fabric assembly doesn’t move out of plumb while it’s being filled.

The cost of this fence varies widely based on what kind of rock is chosen (river rock is the least expensive) and whether or not a skid steer loader has access to work from one or both sides.

The City of Phoenix requires engineering and a building permit for six foot tall masonry fences. This one has no footing between the internal steel posts.


DEBRIS FENCES

This fence contains the concrete and cinder block debris left after tearing out an old patio. Block that hasn’t been grouted breaks up easily with an ordinary hammer.

Concrete, especially if it’s over four inches thick, is tougher. We used a pneumatic jack hammer to break it up into pieces that could be placed between the welded wire panels.

This fence design is eight feet tall x eight inches wide. Cross-tie-bars insure it will stay straight and plumb regardless of what you put in it.

Cost for six foot tall versions with (for instance) cmu debris is about $25/s.f. with good equipment access.



GRAVITY WALL

These Versa-Lok masonry units are 12 inches wide and laid on a compacted aggregate leveling base. No concrete foundation is required.

Each block weights 80 lbs and is pinned with nylon dowels and dry stacked without mortar. Only the cap blocks are glued down.

The I.B.C. (International Building Code) requires a guard rail if the falling hazard exceeds 30 inches.

Gravity walls are a little less expensive than 8 inch CMU retaining walls without stucco, paint or damp-proofing.