In Victoria, we see a lot of retaining walls with mortared joints. Triton Landscaping does both mortared and non mortared walls. Here are the strengths and weaknesses of both.
Mortar Can Crack
Mortar is soft. It’s like a glue that binds bits together. While made from similar materials, it’s not hard and solid like concrete. What happens when part of a wall shifts ever so slightly is that cracks have to form to relieve the pressure. In a similar wall without mortar, the pieces of the retaining wall whether it’s boulders or blocks will move the same amount as the mortared wall but they will be imperceptible. Whereas for the mortared the wall, you now have cracks interlaced throughout, which can be a real eyesore. So then you are left with two choices: live with the cracks on an otherwise structurally sound and pristine wall or demo sections of it down and remortar it.
Flexibility of Dry Stack
The same advantages that allows a paver walkway or driveway shift as opposed to giant concrete slabs cracking is what allows a retaining wall that isn’t mortared together to ebb and flow with the seasons. The mortar is nowhere near strong enough to prevent a poorly built wall from failing.
Additionally, a non mortared wall is full of joints that allows water to flow through the wall. This prevents the build up of hydrostatic pressures that will overcome the wall and tip it over given enough time.
It’s Really Personal Preference
Aesthetically, some people prefer mortared walls, especially when other parts of their property or neighborhood has a similar look and they want it to blend in. Ultimately this comes down to personal choice. There are plenty examples of both types in Victoria BC. If you need a wall built or repaired, let us know and we’ll see what we can do for you.