How to Build a Concrete Block Wall
Concrete block walls have many uses ranging from residential to commercial.
You can use large concrete blocks to build retaining walls, security barriers or massive bins for certain products and materials.
Regardless of the block wall’s purpose, the basic steps for building it remain the same.
Before we begin, it’s important to check local building codes for area construction requirements.
Next, always wear eye protection and waterproof gloves when working with cement-based products.
On-the-job injuries could result in permanent eye damage but wearing protective eyewear can prevent an estimated 90 percent of eye injuries, according to OSHA.
Similarly, severe skin injuries, such as caustic burns, and illnesses, such as contact or allergic dermatitis, can result from exposure to wet cement. So wearing waterproof gloves is a must.
Once all safety precautions are met, here are the steps.
Ensure you have a solid footing. Footings should be at least twice the width of the concrete block and extend below the frost line.
For load-bearing walls, set tie rods at least 6 inches into the concrete footing before it is set. Rebar should be placed in every other masonry core to provide structural support.
For masonry cores over 4 inches wide, Quikrete Core Fill Grout–Coarse should be poured around the rebar; for masonry cores under 4 inches wide, Quikrete Core Fill Grout-Fine should be used.
Lay out the block, leaving a 3/8-inch gap between the blocks to allow for the vertical mortar joints
Ready to build a concrete block wall? Watch the step-by-step video here.
Snap a chalk line on each side of the block wall as a reference line.
Mix mortar. When preparing to place a trowel full of mortar, gently “snap” the trowel downward to remove any excess mortar. The proper consistency is achieved when the wet mortar will “hang” on a trowel held at a 90-degree angle.
Dampen the footing surface with water and place a 1-inch bed of mortar on the footing. Furrow the mortar bed using the tip of the trowel to create a “v” to help distribute the mortar evenly. The mortar should be workable but firm enough to support the weight of the block.
Butter the inside end of the first block and then press the block into the mortar bed to create a 3/8-inch mortar joint.
Trim and remove any excess mortar.
Using the same process, set the opposite corner block.
Repeat steps 6 and 7, adjusting the blocks to be flush and level; continue this process until the first course is completed.
To set the next course of block, apply a 1-inch thick mortar bed along the top of the first course.
At the end of the wall, set an “8x8x8” half block into the mortar bed with the smooth side facing out.
Using a mason’s line as a guide for the remaining block. Continue building the wall until it is complete.
Once the mortar joints have become “thumbprint” hard, use a jointing tool to smooth the fresh joints and remove any excess mortar.
Want to learn more about concrete mix, concrete sealers and crack repair? See quikrete.com.