Quck answer
Building a concrete block shed involves several steps. First, prepare the ground by leveling and compacting it. Next, lay a concrete foundation by mixing cement, sand, and water, and pouring it into a wooden form. Once the foundation is set, start building the walls using concrete blocks and mortar. Make sure to leave openings for windows and doors. After the walls are built, add a roof using wooden trusses and plywood. Finally, finish the shed by painting or applying a protective coating. With proper planning and construction, a sturdy and durable concrete block shed can be built.
A foundation made of a slab or footer is necessary when building a shed with concrete blocks. The foundation should be level, square, and built to the appropriate depth based on the frost line in the area. By having a solid foundation, many of the issues associated with constructing a concrete block shed can be avoided.
Step 1
Use the concrete block calculator provided in the Resources section to determine the number of blocks needed for the project. The quantity may vary depending on the placement of doors and windows.
Step 2
Place the first row of blocks without mortar to determine the exact number of blocks required for the entire run. Use a strip of 3/8-inch plywood as a spacer to ensure that the concrete blocks are evenly spaced along the foundation and within the alignment lines. Start with a corner block aligned with the outer edge of the foundation and continue until the first row is complete.
Step 3
Use a chalk line to mark guidelines on both the inside and outside of the block runs, as well as between the concrete blocks. This step is optional and can be helpful for those who are new to working with concrete blocks. After marking the guidelines, remove the blocks and prepare for the mortar application.
Step 4
Hang a plumb bob 3 feet away from each corner and on the center string. Regularly check the alignment of the plumb bob during the construction process. This vertical plumb line ensures that the walls are being built straight.
Step 5
Follow the manufacturer’s instructions to mix the mortar. Spread a 1-inch thick and 8-inch wide layer of mortar evenly along the foundation. Begin by placing the first corner block, which has a smooth finished edge and looks different from the other blocks. The precise placement of this block is crucial, as it will affect the alignment of all the other blocks in the row.
Step 6
Apply a 3/8-inch thick layer of mortar on the sides of the concrete block that is adjacent to the corner. Firmly place the block in the mortar bed and continue working until approximately 4 feet of blocks have been laid on each side of the corner block. Use a mason’s level to ensure that the block wall is level and plumb. If necessary, use a rubber mallet to make slight adjustments to the blocks before the mortar sets. Continue working until the first row of concrete blocks is complete.
Step 7
Thoroughly check all corners and concrete blocks in the first row for plumb and level. Any small mistakes made at this stage can cause significant issues later in the project. Apply a 3/8-inch thick layer of mortar and lay the subsequent rows of concrete blocks on top of the first row. Lay the blocks in the opposite direction of the first row to create a staggered pattern. Use jamb blocks for door and window openings.
Step 8
Continue laying concrete blocks until the desired wall height is achieved. In the final row of blocks, insert anchor bolts every 3 feet at the top to attach the wooden framing. Fill the holes around the anchor bolts with mortar and level it with the top of the blocks.
Step 9
Install the preferred roofing material on top of the wall. Proceed to install doors and windows.
