J-Block Retaining Wall Block

J-Block is one of the easiest do-it-yourself retaining wall systems available. It requires no mortar, footings, or interlocking pins. Each unit weighs only 30 pounds allowing for fast and easy installation. J-Block are light enough to be installed by just about anyone. With the built in set-back lip on each unit, proper alignment and set-back are automatic. With a little imagination and a few hand tools it is easy to build straight walls, inside curves, outside curves, and anything from a few inches up to 2 ft in height. That means you can create retaining walls, tree rings, planters, terrace gardens, steps and much more.

Product CodeDescriptionDimensionsSq Ft CoverageWeightQty Per Pallet
JBCGJ-Block Concrete Gray Color5″H x 12″W x 8″D.42 Sq Ft30 lbs96
JBSGJ-Block Sunset Gold Color5″H x 12″W x 8″D.42 Sq Ft30 lbs96
JBSTJ-Block Sahara Tan Color5″H x 12″W x 8″D.42 Sq Ft30 lbs96
JBCRJ-Block Cardinal Red Color5″H x 12″W x 8″D.42 Sq Ft30 lbs96
JBMCMJ-Block Midnight/Cardinal Mixed Color5″H x 12″W x 8″D.42 Sq Ft30 lbs96

J-Block Installation Instructions

Plan Your Project

Before beginning construction, prepare a layout plan of the wall. It is not recommended to go higher than 5 courses of J-Block (25″) and a proper foundation and drainage becomes more critical the higher you go. Be sure to consider the draining patterns, soil conditions, surcharges and the local building codes. If you have any questions ask your local dealer or a qualified engineer.

Prepare the Foundation / Leveling Pad

A solid foundation is essential to ensure a well constructed, long lasting wall. The foundation leveling pad should be at least 16″ wide and 6″ deep and composed of a compactable stone material like #53’s. A 1″ layer of sand can also be added to the top of the #53’s base to help with leveling of the first course. The first course of block should be started 1″ below grade per 1′ of designed wall height (a 2′ tall wall would require the first course of block to be 2″ below grade).

Install the First Course

Place the first course of J-Block on the leveling pad with the built in set-back lip facing down. Level the J-Block from side to side and from front to back with a carpenters level. Use a string line to insure a straight line. It is very important that the first course is installed level.

Install the Backfill

Backfill with a clean, free-draining course aggregate such as #8 crushed stone or L-Gravel at least 12″ behind the J-Block wall. Compact each layer as you go. Use of organic topsoil or clay type soil is not recommended for backfill. Fill in directly behind the wall for approximately 12 inches. It is important to backfill each course as it is installed and compact each layer. A drainage pipe outlet at the bottom of the wall may be required for taller walls.

Install Additional Courses

Position each additional course of J-Block on the preceding course and straddle the top block half way on top of the two lower block. This staggers the vertical joints of the wall. No mortar or interlocking pins are required. Just simply stack the J-Block and the built in set-back lip will automatically establish the required stagger. It is very important to remember to backfill each course as it is installed. Repeat the last two steps to build a wall as high as 25 inches (5 courses above grade).

Breaking a J-Block Unit

Draw a line where the J-Block unit is to be broken. Take a brick chisel and hammer and go back and forth over the line until the unit breaks. A masonry saw can also be used. Chips and flying particles can be encountered when cutting or breaking concrete. Be sure to take proper precautions. Safety glasses are recommended.


NMCA Segmental Retaining Wall Installation Guide

For more information, see the below installation guide from the National Concrete Masonry Association.