Building a Limestone and Concrete Retaining Wall

Building a limestone and concrete retaining wall can be a difficult job for someone who isn't used to building anything as complex. But it doesn't have to be. If you use the right tools and apply a bit of pre-planning and hard work, you can create a wall that will retain water on your property and allow the natural free-flow of water to surrounding areas. Just follow these easy-to-understand steps.

Preparation

Step 1

Pick out an area where you plan to build the retaining wall, then outline it either with spray paint or chalk. This will give you a better indication of the length and width of the wall before you begin building.

Step 2

Along the outline, dig and erect the footing into the ground using wooden planks. A 2-by-4 inch board is the best material for this type of construction. Dig deep enough into the ground so that you are below the frost line. Make certain the footing is twice as deep and twice as wide as the retaining wall you plan to build. Also allow for enough space for drainage so that the wall won't prevent the natural overflow of water into other areas or nearby property.

Step 3

Hold footings in place with wooden stakes. Separate the stakes or palings every 3 to 4 feet in length. Make certain the footings are level.

Step 4

Pour concrete into footing to create the base. This will form the foundation of the wall. Using a spatula, level off the concrete so it is uniform. If needed, fill any spots that aren't level with the rest of the base or remove any excess concrete.

Step 5

Allow the base to dry. This may take up to three days.

Building the Wall

Step 1

Use wooden stakes or other wood materials from the job and drive them into the ground to stake out the corners of the retaining wall. To locate where each corner will be, use a line and stretch it from one corner to the next. Wherever the two lines cross will be the point in which the corners will form. Erect the wooden stake in positions at least 2 feet in either direction at the point where these lines cross.

Step 2

Before laying down the blocks, deduce the specific amount of blocks needed when you lay down the first course or level on the concrete. Do a test run before the actual building to determine this. Lay down each block. Use corner blocks and cutting blocks to create better fits as needed.

Step 3

Use a plumb bob or any heavy weighted material tied at the end of a string and mark corner positions at least 3 feet from each corner. Mark the position with spray paint or a pencil.

Step 4

Apply mortar at the marked position, spreading at least as wide as three or four blocks. The mortar should be about 1-inch thick and 8 inches wide. Place a furrow in the mortar with a trowel to create an edge for each laid block.

Step 5

Begin laying down the blocks with the corner block. Position it in a correct horizontal and vertical position so that it will be aligned and uniform with the other blocks as they are laid down. If the block is not laid down correctly, the other blocks won't be aligned, and the retaining wall will lack uniformity and strength. Once this is done, continue laying down the rest of the blocks for the first course from one corner to the next, applying mortar to each side of the block with a trowel before placing blocks in position. Make adjustments along the way, such as cutting blocks for better fits. You can use a masonry chisel and bricklayer's hammer for this type of job. Once you've laid down at least four or five blocks, check alignment or make certain the blocks are level. If any blocks are out of alignment, tap them to make corrections but do so while the mortar is still wet, as the block will be permanently set in place once it dries. Never remove the blocks once the concrete begins to set.

Step 6

Make certain all mortar joints are spaced at least 3/8 inch apart. This will allow for enough space to fill in the joints. You can use 3/8-inch plywood to measure the space before you fill in the mortar.

Step 7

Continue with the next course. Start with the corner block first and make sure these points are always a block or two higher than the rest of the wall until you finish the entire job. Always make sure the corner blocks, as well as the rest of the blocks, are in complete and uniform alignment. Remove any excess mortar with a trowel to keep the look neat and polished.

Step 8

Depending on the size of the wall, continue building each course. Make sure the blocks are aligned and that there is enough space for mortar joints.

Step 9

Use a damp trowel or brick jointer to scrape all the mortar joints to make them neat and polished. Make certain the mortar is still flexible enough so that it can be pressed with your fingers.

Step 10

Once the wall is finished, begin creating the back fill. This will be behind the wall and allow enough space for drainage. Lay fabric over the ground near the wall to separate it from the soil. Lay 4 inches of drainage tile at the bottom of the pit between the wall and the fabric.

Step 11

Once the tile is completed, begin back filling the area with limestone. Allow a few inches at the top for soil coverage but also leave enough room so that mulch or leaves won't wash over the top of the wall.