Retaining Wall French Drain Detail

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Retaining wall french drain detail.

The process of making sure that a retaining wall drains properly is relatively simple but it is not very flexible. The toe drain and the wall rock is designed to remove incidental water from behind the wall and is not meant as primary drainage path for above or below grade water management. About 8 inches to 2 feet deep should be sufficient for many water diverting projects though related systems such as those built around foundations and sub ground living spaces as well as the bases of retaining walls may be deeper. 41 inch hollow core section pdf dwg.

Alternating planter 5 degree batter wall section pdf dwg. The purpose is to take water from wet areas and disperse it into dry areas. Large batter wall section pdf dwg. In all cases wall rock is located within the cores of the block and a minimum of 12 in.

The size of the gravel used can vary from pea gravel to larger pieces of river rock. If aggregate of different sizes is used smaller pieces usually go closer to the pipe while larger pieces sit closer to and on the. 300 mm behind the block. For a stacked block retaining wall that s no higher than four feet a trench filled with three inches of crushed rock will help keep the wall from shifting and settling.

The pipe should rest on the same compacted gravel base or concrete footing that supports the wall. Any reinforced wall or walls over 4 ft. 1 2 m in height or with slopes or other surcharges above the wall will need a toe drain. Gravity walls solid 41 inch 1030mm hollow core and xl blocks all gravity wall details pdf.

A french drain is a trench dug in the ground into which a perforated tube is placed and which is then filled with gravel or lose rocks. Together these four features will provide adequate drainage for most designs. Block setback options 5 degree batter pdf dwg. Solid block wall section pdf dwg.

Although there are exceptions most retaining walls require gravel backfill soil compaction pipe or toe drains and weep holes. Check out this video for some simple instructions on installing a french drain behind an 18 to 24 tall retaining wall before it is backfilled with dirt. If you re building a retaining wall add a french drain behind the first course of stones or blocks. It s not crazy.

Otherwise water moving down the hill will build up behind the wall and undermine it. Today we re rebuilding a retaining wall that wasn t built correctly. The exact depth of the.