Above, the Keystone retaining wall system by Tileco is a virtually instant wall for do-it-yourselfers. Pre-cast pieces are layered and held together with fiberglass pins instead of mortar.
Above, the Keystone retaining wall system by Tileco is a virtually instant wall for do-it-yourselfers. Pre-cast pieces are layered and held together with fiberglass pins instead of mortar.
Individual pre-cast wall pieces interlock together and the homeowner avoids the strain of mixing concrete in the wheelbarrow. Individual pieces have one curved side, and holes. Stack the pieces, and slip fiberglass pins in the holes to join the wall together.
"We have been making the Keystone walls for about three years," says Dennis Sakamoto, president of Tileco Inc. "It's been used on the mainland for 12 years, and it is getting accepted here.
"Homeowners are doing the shorter retaining walls - say up to 3-feet - and contractors are going with the higher walls. The tallest to date is 16 feet at the top of Mauna Kea, at the observatory, and we have a 10-foot-high wall at a Makakilo home."
Sakamoto says cost of the Keystone system is 30 percent less than a poured concrete wall and 10 to 15 percent less than a rock or masonry wall.
Gravity wall systems have been around since the Egyptian pyramids and rubble stone walls. Friction helps to hold the pieces together. After the layers of wall are put together with the fiberglass pins, then a top (cap) layer is put down using an adhesive.
The Keystone wall pieces are made by Tileco at its Kapolei plant.