©2019 by McLaren Masonry, Inc.

Retaining Walls & Free Standing Walls

McLaren Masonry, Inc. are experts at constructing both free-standing and retaining walls out of poured in place (PIP) concrete and concrete block (CMU)

Retaining Walls

Overlooked costs in retaining walls are the drain lines, waterproofing, and backfill.

A well thought out drainage system can add decades of life to a retaining wall. Most drainage details that accompany blueprints today are boilerplate reproductions from a book. Oftentimes what is drawn simply won't work. The most common detail involves a four-inch diameter perforated pipe encased in in one foot of drain rock wrapped in a geo-tech fabric.

Unfortunately for this drainage system to work, the rock bed must be full. On a 70-foot wall, that would be 70-cubic feet of water required to get flow. 70-cubic feet of water equals 523 gallons of water. That is literally 2 tons of water pressure. Concrete by nature is porous, so that water is prematurely adding to the rusting of your structural steel. Waterproofing your sub-grade concrete and masonry walls by an expert is worth it. 

CMU Hollow Block Walls

vs

Poured or Cast in Place Walls 

Poured in Place (PIP) otherwise known as Cast in Place walls have several distinct advantages over CMU walls.

1. The PIP wall thickness is 100% structural concrete. CMU is simply a shell filled generally with a fine grout containing no aggregate. For example: 8-inch CMU has a maximum 5-inch solid center. 12-inch CMU has a maximum 8-inch solid center.

2. With a PIP wall the structural reinforcement (rebar) is tied in place and visible for inspection prior to pouring. A CMU wall has horizontal rebar that is laid in channels, called knockout courses. These reinforcements can be shifted during the grouting process. Horizontal steel is cut to length and dropped into cells prior to pouring. Is it in the center of the wall? Or is it at the edge of the block? That depends greatly on the skill of the workman placing it. Unfortunately, there is no way to tell after grouting is complete.

3. PIP walls reveal voids, honeycombs or pock holes when forms are removed. They can be patched, sealed and remedied. CMU walls voids cannot be detected until there is a problem.

Poured in Place Wall

Free standing structural poured in place wall