How to Dry Stack Concrete Blocks
It is easy, cost efficient, and particularly fast to dry stack concrete blocks. There are many manufacturers that offer concrete blocks that have a locking system in place to ensure the blocks are sturdy. If you are looking to build a masonry mail box or an addition to your home, you can do it all yourself with the proper equipment and some time.
Step 1 - Prepare the Base
Determine the location of your project. After you mark the perimeter of the area you will be working in, begin to dig the perimeter with your shovel. Take your garden hoe and loosen the grass, weeds and debris and remove it from your area. Be sure you remove any rocks.
Step 2 - Build Form for Base
With your 2x4 boards, build a frame for the outline of your concrete base. After the frame is securely built, mix the concrete per the instructions on the bag for use in Step 4.
Step 3 - Compacted Aggregate
Lay a base of compacted aggregate 2 to 4 inches thick inside the frame. Ensure that the aggregate is evenly distributed throughout the frame to form a good base for the concrete.
Step 4 - Lay the Concrete
After the aggregate is placed inside the form, you may then lay your concrete. You will want your concrete to be a minimum of 3 inches thick to support your structure. Allow the base to cure for 2 to 3 days before building your structure.
Step 5 - Laying the First Course
Locate all the corners of your project and mark each of them with a pencil. Use a chalk line to outline the perimeter of your project. Starting at any corner you choose, lay your bottom course keeping the outside edge of the block on the chalk line. Once your bottom row is complete, check the top of the blocks to ensure they are level.
Step 6 - Building the Corners
You will want to stack the corners first. Once a corner reaches the height you desire, it should be leveled. Plumb level the top and sides of a corner by pushing and shimming the the blocks until they are level. Plumb the blocks vertically and horizontally as well. As long as the first course is level, you will have little shimming to do on the remaining courses.
Step 7 - Building the Wall
Once all corners are leveled, you can now close in the walls. use a mason line from corner to corner to ensure you keep a straight line. Your blocks should slide into each other connecting lip to lip. Be sure to keep the wall tight by sliding the blocks hard on the surface of the other. Sliding the blocks helps to remove any debris that may be stuck on the bottom unit. Check the blocks after stacking to see is any shimming is required. If it is, be sure to start shimming from the bottom units to keep the top of the block level.