Constructing an Interlocking Wall System Without Pins

Constructing a Wall
Constructing a Wall

Materials Needed:

3/4″ Crushed Stone

Allan Block

Fill Material


4′ Level

Tamp Measure

String Line





AJT’S Step by Step Instructions

AJT Step 1 – Preparation and Excavation:
After you have decided where you want your wall and the dimension of the wall, you can start excavating. Dig a trench where the wall will be place 24 inches wide and the length of wall you have determined. The depth of the trench should be 6 inches plus add 1 inch for every foot of wall height. Compact the base of the trench thoroughly. Put a minimum of 6 inches of ¾” crushed stone, compact and make sure it is level.

AJT Step 2 – Install Base Course:
Place Allan Block units on your prepared surface. Make sure each block is level check front to back and side to side. Use a dead blow hammer to tap each block into place. It is critical to level at this stage. Align straight wall sections using a string line or by sighting the grooves on the top of each unit. If your wall has a corner, begin at corner and work out from that point.

AJT Step 3 – Backfill:
Fill in the area in front of the blocks with on site soils as you go. Also fill in the center of the blocks with ¾’ crushed stone as well as 12 inches behind the wall. Make sure base course is level before moving forward.

AJT Step 4 – Adding Additional Courses:
Stack the next course on top, staggering the seams as you go. Check each block for alignment and levelness. Continue to fill each block with crushed stone and backfill as you go. Complete the wall to your desired height. (If the wall is over 4’ consult an engineer)

AJT Step 5 – Installing Caps:
You are almost done! Now complete your wall by placing Allan Block cap units on top of the last course of block. Use concrete block adhesive to secure cap. And you are done.