How to Lay a Mortar Bed

Mortar anchors concrete blocks and bricks to the concrete footing below.

Mortar beds serve as the anchor points for walls and other concrete-block and brick constructions. Mortar is a soft and pliable material when wet and a solid and sturdy adhesive when dry. Mortar beds stay wet long enough for you to properly lay and set each piece of the wall or structure you are constructing. Mortar beds also dry quickly enough to make them a practical construction method. The process of laying a mortar bed is straightforward and requires only a few basic tools -- and a plan.

Things You'll Need

• Concrete blocks
• Bricks
• Chalk line
• Trowel
• Level
• Rubber mallet

Instructions

1. Mark the course of your concrete-block or brick wall on the concrete footing you should already have installed below ground. Place one row of concrete blocks or bricks along the top of your footing where you would like them to line up. Use your chalk line to snap the two ends along the front edge of the blocks or bricks. This line will be your guide when laying the mortar bed.

2. Prepare your ready-mix mortar according to the manufacturer's instructions. You will require a mixing surface and water to perform this task.

3. Use your trowel to apply a 1-inch-thick layer of mortar to the concrete footing. Keep the mortar about 1/2 inch inside the chalk line to avoid covering your guide. Create a smooth layer of mortar by using your trowel edge as a screed. Apply only enough mortar to set 3 to 4 blocks at a time. This will allow you to slowly form the wall while keeping all the blocks straight and the mortar even.

4. Slide the pointed front edge of your trowel through the wet mortar, and create grooves or trenches which run the full length of the mortar. These grooves help to spread the mortar evenly over the underside of the blocks or bricks and ensure a solid hold.

5. Place the first block onto your mortar bed, and continue until the mortar has been covered. Apply more mortar to the concrete footing and repeat the process until the project is completed.

Tips & Warnings

• Use a level to set each block or brick on your mortar bed. Place the level from right to left and check that the block is plumb. Then turn the level from front to back and check again. Use a rubber mallet to work each block into position before moving on to the next one.

• Use caution when working with heavy concrete blocks and bricks. Lifting them incorrectly can cause serious injury.

References

• Quikrete: Concrete Block Construction
• Walks, Walls & Patios: Plan, Design & Build; Editors of Creative Homeowner, et al.