Building a concrete block wall is one of the more involved building projects, requiring careful planning and a little heavy lifting. Regardless of your skill level, a successful result can be achieved. Every block wall, regardless of whether it is going to be a structural wall or a non structural wall, requires a solid footing. High-strength QUIKRETE 5000 (or Q-Max Pro) is the recommended product for footing construction because of its high strength and rapid strength gain.
Footing should be at a minimum of twice the width of the concrete block. A typical eight by eight by 16 block would require a 16 inch wide footing. The footing depth should extend below the frost line. Make sure to check local building codes for construction requirements in your area. Snap a chalk line on each side of the block wall, as a reference line.
QUIKRETE Mason Mix Type S is the recommended mortar mix for constructing structural and non-structural block and brick walls. This pre-blended mortar mix is extremely workable and achieves the high bond strength required for successful project. One 80 pound bag of mason mix will lay up to 13 standard concrete block. 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 one-inch bed of mortar on the footing. The mortar should be workable but firm enough to support the weight of the block. Press the first block, the corner block, into the mortar bed, to create a 3/8 inch mortar joint.
Make sure the block is level and properly aligned, before proceeding to the next block. Then trim and remove any excess mortar. Using the same process, set the opposite corner block. Butter one end of the block and set it next to the corner block. Then, press the block down into the mortar bed and against the previously laid block so that the mortar joint is 3/8 inch wide. Adjust the block so that it is flush and level. Continue this process until the first course is completed.
To start the second course, apply a thick mortar bed along the top of the first course. At the end of the wall, set an 8 x 8 x 8 half-block into the mortar bed, with the smooth side facing out. This process will create a very strong running bond pattern that ties the wall together. Use a Mason line as a guide for the remaining block. Continue building the wall until it is complete.
Once the mortar joint has become thumbprint hard, use a jointing tool to smooth the fresh joints and remove any excess mortar. For load-bearing walls, tie rods should be set a minimum of six 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 four inches wide, as is common with standard 8 x 8 x 16 block, QUIKRETE Core Fill Grout – Coarse should be poured around the Rebar. For masonry cores under four inches wide, QUIKRETE Core Fill Grout – Fine should be used.
Project Instructions
When working with cement-based products, always wear eye protection and waterproof gloves.
Step 1
Ensure a solid footing. Footings should be a minimum of twice the width of the concrete block (i.e., a typical 8x8x16 block would require a 16-inch wide footing) and extend below the frost line.
NOTE: it is important to check local building codes for construction requirements in your area.
For load-bearing walls, tie rods should be set a minimum of 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.
Step 2
Lay out the block, making sure to leave a 3/8 inch gap between the blocks to allow for the vertical mortar joints (i.e., a typical 8x8x16 block is actually 15-5/8 inches long and 7-5/8 inches high to accommodate the mortar joint).
Step 3
Snap a chalk line on each side of the block wall as a reference line.
Step 4
Mix Mortar.
TIP: 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° angle.
Step 5
Dampen the footing surface with water and place a one-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.
Step 6
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.
Step 7
Trim and remove any excess mortar.
Step 8
Using the same process, set the opposite corner block.
Step 9
Repeat steps 6 and 7, adjusting the blocks to be flush and level; continue this process until the first course is completed.
Step 10
To set the next course of block, apply a one-inch thick mortar bed along top of the first course.
Step 11
At the end of the wall, set an “8x8x8” half block into the mortar bed with the smooth side facing out.
Step 12
Using a mason’s line as a guide for the remaining block, continue building the wall until it is complete.
Step 13
Once the mortar joints have become “thumbprint” hard, use a jointing tool to smooth the fresh joints and remove any excess mortar.
Shopping List
- 80 lb QUIKRETE Mason Mix – Type S
- 8x8x16 standard block
- 8x8x8 standard block
- Masonry brick trowel
- Mason’s line
- Line chalk
- Masonry line blocks (2)
- Stiff brush
- Jointing tool
- 4’ level
- Plastic mixing tub or wheel barrow
- Mixing hoe
- Measuring tape
- Gloves
- Safety glasses
(For Structural walls)
- #3 rebar
- 80 lb QUIKRETE Core fill grout or
- 80 lb QUIKRETE 5000 Concrete Mix
(Footing Construction)
- 80 lb QUIKRETE 5000 Concrete Mix
- 2×4 or 2×6 form boards
- Wood stakes
- 50 lb QUIKRETE All Purpose Gravel
- Nails
- Hammer
- Wood float
- Shovel
For more project ideas just like this, visit QUIKRETE.com
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