What’s the Best Base for a Retaining Wall?

A retaining wall is only as strong as its foundation. Before you can start building up the blocks of your retaining wall, it’s crucial that you give plenty of attention to the base.

Here’s an overview of what you need to know about preparing the base for your retaining wall so it will last you for years to come. And remember, working with a residential concrete contractor in Marinette County, WI will help ensure the success of your project.t

Preparing the base area

Before you even start working with the material you’ll use for the base, you need to prepare the site. Place stakes around the area to denote the exact location of the front of the retaining wall, and use a string line or paint to mark the whole length. You can then begin excavation, removing all vegetation and organic material at the surface. Do not use the removed material as backfill—you should use other, “clean” soil instead.

Some types of walls might need extra reinforcement, in which case you should excavate behind the wall to accommodate the length of your designed geogrid.

Moving forward, you should start from the lowest point to dig a base trench for the entire length of the wall. It should be 24 inches wide in most cases—this is the standard width of retaining walls. The depth of the trench should be six inches, plus an additional inch for every foot of wall height. You can then compact the base trench by making a couple passes with a plate compactor.

The compaction process is important, because without it the base could settle or shift. Compacting the soil makes it denser and harder to move. In addition, soils used at the foundation must be heavy and firm. If there are heavy clay or wet soils, or if the area had been excavated before, you should remove the material and replace with a granular material.

Beginning work on the base

Once you’ve finished these steps for preparing the base, you can then move on to installing the base material.

You’ll need to use a drain pipe for any reinforced wall, or any wall that’s taller than four feet. The drain pipe should be located at the lowest possible position near the back of the trench, and should have venting to daylight every 50 feet (15 meters).

There should be a minimum of six inches of wall rock placed in the base trench, which should then be raked smooth upon filling. Compact that wall rock with a plate compactor; this might take a couple passes to accomplish appropriately. You should regularly check the entire length for level as you go through the process, and make any necessary adjustments.

This is just a short overview of what you need to know about developing a base for a retaining wall. If you’re interested in learning more about the processes we use to ensure your retaining wall will last you for many years to come, we encourage you to contact Kwiatkowski Construction Co., Inc. We’re proud to be your source for residential concrete in Marinette County, WI!

Categorised in: Retaining Walls

This post was written by Writer