How To Do Drainage Behind A Retaining Wall

This collected water freezes and expands which pushes on the wall causing it to fall over.

How to do drainage behind a retaining wall. Id like some advice on how best to install some drainage behind an existing retaining wall. Second a retaining wall must have properly compacted backfill. In order to provide proper drainage at least 12 inches of granular backfill gravel or a similar aggregate should be installed directly behind the wall.

For more on how drainage stone fits into a drainage system check out this post. When we build a retaining wall we dont only hold back the soil w. It is just over 6 metres long.

The drainage stone will be installed at the back of the retaining wall and will extend 12-in behind the wall. Here are the top 3 ways to prevent drainage disasters when building your retaining wallInstall the drainage pipe correctlyAfter laying the first course of blocks lay an agricultural drainage pipe with a geotextile sock ag-pipe behind the wall on a bed of 10-20mm clean free drainage materialEnsure that the drainage pipeHas at least a 1 in 100 fall away 1cm drop over 1m length of wallHas a geotextile sock to prevent silt blocking the drainage. Poor drainage is often the cause of retaining walls failing and then it is often too late to put right.

Sometimes this means a pipe running through the wall from the soil to the other side. Our systems also help the walls stay intact no matter how much water the soils behind them absorb. Compacted native soil can be used to backfill the rest of the space behind the wall.

This is so that when water gets into the space it does not become bogged down in soil but instead can flow down the wall to the drains or weep holes. In other failed walls weve seen water collect behind the wall. Because of the danger of allowing water to accumulate most retaining walls have built-in drainage mechanisms.

When we build a retaining wall we. Retaining walls also fail because the base layer was not leveled properly. In order to provide proper drainage at least 12 inches of granular backfill gravel or a similar aggregate should be installed directly behind the wall.