National Association of Women in Masonry

One of the thing that you will probably want to try your hand at is laying up a nice looking stone wall. There are a few ways of doing this depending upon how skilled you are or how much time you want to spend on learning how to do it by trial and error. This article will deal with a mortared stone wall as opposed to the more traditional dry stone wall that you often see in farmed fields and open pastures in the countryside.

First of all, trial and error when applied to the building of a stone wall can be a long and arduous job, because you are going to male more mistakes than you will want to and each one can be costly because often you don’t notice your mistake until you have added one or more courses of stone and mortar. That means taking it all off and going back to the errant stone placement. Not a nice job. But one thing’s for sure, if you make that kind of mistake, you will be pretty unlikely to make it again!

Traditionally Mortared Stone Wall

The traditional way of laying up a mortared stone wall is to literally do it stone by stone. That means having a good eye for a straight line both horizontally and vertically. The use of a good spirit level is a necessity as well as a length of good old reliable string to keep things on the straight and level. Apart from understanding the need to have a pre-laid foundation base to carry the weight or the wall (so it doesn’t go sinking into the earth below) and the careful placement of each course of stones so that each stone is placed across the join between two stones below (and, naturally above) in the formation of “two over one” then the rest is pretty straightforward.

This article assumes you already know how to mix and make the mortar for your wall. The consistency of the mortar needs to be similar to that of bricklaying and you need to make sure the individual stones are clean. A large bucket of water and a scrubbing brush are usually good enough to get most of the foreign material off the stone’s surface so that it is clean enough for the mortar to stick.

Slip Form Stone Wall

If you want a slightly easier to lay up wall, then using slip forms is a good way especially if your eye for that all important straight line is not as accurate as you’d like it to be. This method uses pre-formed shuttering to encase the newly laid wall on each side, creating ready made straight lines both horizontally and vertically, although you will still need that spirit level to prove levels. See image below of four slip forms laid together to form a part of the intended wall:

The forms are created by taking lengths of plywood board in whatever dimensions you can get them but the length should be no more than twelve feet and the height no more than three feet. You then strengthen each form with lengths of 2×2 softwood planks laid horizontally one at the top and one at the bottom of each board with vertical noggins to give added strength. You need to be able to lift each form, which is the reason for the size limitation. Two forms are then laid out with one on each side of the intended wall’s width. You’ll need to leave a generous width to accommodate two stones one either side plus some space in the centre for the back-filled concrete that gives the wall its strength and cohesion. Additional forms are laid end-to-end to create the desired length, depending on how many forms you can afford to have.

Once the foundation has been laid and is set and the forms are in place, you can start placing your chosen stones with the best face facing outwards on each side, butted up against the sides of the forms (shutters). Then you in-fill the space between them with concrete. For a stronger wall (and especially if you intend it to be of any appreciable height) you can add steel rebar mesh in the centre of the wall for added strength.

Once you have reached the height of the first row of forms, you then place the second row on top of the lower row, wiring each side together to stop it moving and battening along the top. then continue laying the stones and backfilling with concrete. If a further level is required for extra height, the lower forms are removed and placed atop the second row of forms, and work continued.

Its a lot simpler this way and you get a very straight, accurate and constant width wall. Once the concrete has all dried and you remove the forms, you can point between the stones or leave for a more natural looking finish.