Interlocking Block Walls Stack Up Well Against Mortared Ones

Retaining walls are a real staple of the landscape business. Not only can they solve a wealth of erosion problems but they can also lend a lot of character to otherwise uninspired grounds. And a decent, serviceable wall can be made out of a wide range of materials to suit just about anyone’s taste.

We’ve all seen our share of concrete, concrete block, brick, stone, log and even railroad-tie walls. Many of these still look wonderful after years of great service. Unfortunately, many don’t look so wonderful.

It can seem that for every wall you see in good condition, you’ve seen at least two that are failing. Some are cracked, some are crumbling and some are leaning so far, they seem to defy gravity.

One of the biggest troubles with traditional retaining walls is that they are difficult to build well, especially for the inexperienced worker.

It’s relatively easy to erect a wall that looks good when you’re done. It’s quite another to have the same wall look good in three months and still another for it to look good after a cold, hard winter.

Construction difficulties normally associated with retaining walls have all but disappeared with the invention of today’s simple interlocking block systems. Several are on the market, and each has a slightly different method of interlocking and a somewhat different palette of colors.

But their similarities far outnumber their differences. All are made of cast concrete with a single block weighing about 20 to 30 pounds. All are designed to be laid up dry, so no mortar and no mortaring skills are necessary.

Finally, because the blocks, which are supported with re-bar, aren’t joined together with mortar or by other means, hydrostatic pressure cannot build up behind the wall; water simply seeps through the cracks between the blocks.

All these advantages wouldn’t be worth much if the blocks were ugly, but they aren’t. The exposed sides of the blocks are heavily textured, the result of the block being cast and then broken at the factory. The irregularity this causes lends an authentic stone-like appearance to the finished wall.

One way to find out if you like it is to visit a masonry supply yard where various blocks are on display. And don’t be satisfied with looking at an individual block. It’s much better to see a whole wall.

If the supply house doesn’t have the blocks on display, ask for some locations where they know the blocks have been installed and take a ride by to see if you like the results.

Prices vary, but shopping around found prices of about $1.75 a block, and that included a good discount for buying in volume. If you want to build a small wall of 100 blocks or less, expect to pay at least $2 a block, delivered.