Building A Concrete Block Retaining Wall: An Exhaustive DIY Guide

Phase 1: Site Preparation and Layout

First, determine the wall’s length, height, and location. Mark the area with stakes and a string line, ensuring it is level. Remove any obstacles, including plants or rocks. Dig a trench about twice the width of the concrete block and deep enough to accommodate the first row of blocks buried halfway.

Phase 2: Foundation Installation

Fill the trench with a layer of gravel for drainage and tamp it down firmly. Check for level and adjust as necessary. This is the foundation for your concrete block wall, so it’s vital to get it right.

Phase 3: First Row of Blocks

Start by placing the first concrete block, ensuring it’s level both side to side and front to back. Place the rest of the blocks, checking each for level. Adjust with gravel as necessary. Fill the concrete blocks’ cores with crushed stone for additional stability.

Phase 4: Additional Rows

Apply a layer of mortar on the first row, then start placing the second row of blocks. Stagger the joints, much like bricklaying, for increased wall stability. Check for level frequently.

Phase 5: Installing Rebar and Fill

Once the second row is completed, insert rebar into the concrete blocks’ cores for added strength. Backfill the area behind the wall with gravel for drainage, compacting it as you go.

Phase 6: Continue Building

Continue the process of adding rows, inserting rebar, and backfilling until you reach the desired height. Remember to check for level with each row.

Phase 7: Installing Drain Pipes

Install a perforated drain pipe behind the wall, ensuring it slopes away from the wall for proper drainage. Cover the pipe with gravel and wrap it in landscape fabric to prevent silt from clogging the pipe.

Phase 8: Capping the Wall

Once the wall reaches the desired height, cap it with capstones for a finished look. Apply mortar to the top row of blocks and place the capstones, adjusting for fit and checking for level.

Phase 9: Backfill and Clean Up

Backfill the rest of the area behind the wall with soil. Clean off any excess mortar on the wall and let it cure for several days before any heavy rainfall.