1.
Dig a base trench 16 inches wide and 6 inches deep. Remove all vegetation and unsuitable organic soils. (Do not use these for structural backfill)
Compact the soil base properly.
5.
As you lay each unit of the first row, check the level of the block from side to side and front to back. Careful preparation of this base row is the key to having a successful and attractive finished project.
2.
Fill the trench with 4 inches of well-graded gravel material, (1/2" minus or 3/4" minus road mulch) compacting firmly in 2-inch layers to ensure proper compaction.
Note: Hand tamping tools may be used, but vibrating compaction equipment is recommended.
6.
Start stacking the remaining rows; make sure to sweep the top of each course of units to clear debris. Half stagger the next row so each unit is centered on two units below. Pull each unit forward to lock connecting lugs in place.
3.
Level the gravel base from front to back and side to side. This procedure will ensure a straight and stable wall.
7.
Fill the hollow core of the units and the trench behind the wall with free-draining crushed gravel, making sure to carefully compact this material to help lock the units in place. Repeat this procedure for each row.
4.
Lay your first course using a string line to help with alignment. Place each unit edge-to-edge, lining up the back of the units with the string. For smooth curves use flexible 1" PVC pipe as your guide.
8.
Place filter fabric on top of the backfill and drainage materials. This will ensure that the “drainage chimney” remains clear. Cover with topsoil.
Sweep off the top course of units. Secure caps to the top of the wall using an approved concrete adhesive. Use a level piece of string to properly align the capping.