Dry vs Wet laid Stone Walls:
One of the first questions many homeowners ask when proposing a new stone wall is whether the wall should be built with or without the use of mortar. (A “wet” stone wall uses mortar, while a “dry” stone wall does not). Different factors can effect this decision, but we at Concord Stoneworks will most often recommend a dry stone wall. In this article we will discuss why this is so and the advantages and disadvantages of either option.
How they are built:
A wet stone wall is designed as a rigid structure. When external forces are exerted on the wall, (ground settling, frost heaving, errant snow plows, etc.), the wall is designed to withstand the forces and hold its form. A well-built, mortared stone wall with a solid base and backing will hold up for quite some time, yet, it is inevitable that at some point movement will occur. When it does, and when the forces become too great for the wall to withstand, the material cracks. When this occurs the repairs are not easy. Patchwork will be unattractive and do little for the structural integrity. Rebuilding the wall or portions of it will be labor intensive and may require all new material.
Mortared Stone Wall – Split Face Stones
On the other hand a dry laid stone wall is flexible. Water drains through it naturally, and any minor settling or shifting that occurs is absorbed by the wall and goes largely unnoticed. Even if major failure does occur for some reason, the wall or portions of it are easy to dismantle and rebuild using the same material. Repaired portions will also blend seamlessly into the existing wall.
Advantages of Mortared Walls:
One of the advantages of a mortared stone wall is that it is easier to achieve a high level of finish. While building the wall, the mason can rely on the adhesive properties of the mortar to hold the stones in place. This makes it easier to focus on facing the wall to create a very flat and consistent finish.
Mortared stone walls can also be preferable for areas of high traffic. If your stone wall will often be walked or sat on, or is in a very public place where someone could pull stones off the wall, it can be advantageous for the stones to be mortared in place so they do not shift or move due to human interference.
Advantages of Dry Stone Walls:
A dry stone wall relies gravity only to hold the wall together. Each stone is laid with structural integrity in mind. Instead of facing the wall with a stone’s flattest face, the stones are stacked so that the heft of the stone ties back into the wall and holds everything together. This produces a more traditional look. High finish dry stone walls are also possible, but take extra time and care to produce.
Since dry stone walls drain naturally, there is no need to add weep holes or drain pipes through the front of the wall. In mortared stone walls these drain pipes/weep holes are often visible and take away from the natural aesthetic of the stone. Also, the draining water can leave visible stains underneath the pipe where it runs out.
If you are a nature lover, a dry stone wall also provides homes for various animals that enjoy the protection of the various cavities within the wall.
Lastly and most importantly, it is often less costly to build a dry stone wall. Wet stone walls require a rigid concrete base, mortar for the wall and the machinery/labor to mix the mortar, and proper drainage. This additional prep work is necessary to try and prevent any movement.
Dry stone walls on the other hand are built with a simple gravel base and backing. They require no additional drainage and the only material needed is the stone itself.
Dry stone walling is a unique skill that not all masons fully understand and appreciate. Although there is a time and place for wet stone walls, we at Concord Stoneworks much prefer the aesthetic, function, and efficiency of a dry stone wall.