How to Build a Motared Stone Wall

1. Tools and Materials Checklist

 

u Tape Measure
u Stone Chisel
u Concrete for Foundations/backup
u Selected Stone

u Heavy Hammer
u Trowel
u Sand and Mortar
u Level

 

2. How to Figure Amount of Stone Required

For a solid stone wall, we first need the volume of stone in the wall in cubic feet. To do this, determine the length, height and thickness of the wall in feet. The general rule of thumb for a retaining wall is that the thickness of the wall at any point should be half of the height of the wall above it. For a 4' high retaining wall, the base should be about 2' thick, and then taper uniformly as it rises. If you are constructing a free-standing wall, the thickness is governed by aesthetics. The shorter the wall, the narrower it can be. For most wall stones, the minimum thickness is about 1'. For a 4' high retaining wall, the average thickness would be: (2' (at base) + 1' (at top))/2 = 1'-6"

If your wall is going to be 20' long and 4' high, the the calculation is as follows:

20' x 4' x 1'-6" = 120 Cubic Feet

Most stone is going to yield about 15 Cubic Feet per ton, so:

120 Cubic Feet = 8 Tons
15 CF/Ton

For a veneered stone wall, we need to know how many square feet we need to cover. For example, if the wall is 20' long and 4' high, the calculation goes like this:

20' x 4' = 80 Square Feet

Most veneer stones are either 4" maximum thick or 6" maximum thick. A 4" veneer with a minimal amount of trimming and fitting will cover about 40 SF/ton, while a 6" veneer will cover about 30 SF/ton. In our example:

80 SF = 2 tons 4" veneer or

80 SF = 2 2/3 tons 6" veneer

40 SF/ton 30 SF/ton

3. How to Construct Your Wall

First you must dig a trench for a footing. This must extend below the frost line (this varies depending on location, but in the Boston area is about 30" to 36" deep). The trench should be about 6" wider on both sides of the wall. You then pour concrete into the trench, level it and let it set.

Before you start building, make a pile of the flattest stone to use to cap the wall (if you are going to use a coping to finish off the top of the wall, you can skip this step). Then, make another pile with pieces that you can use for corners. Now mix your mortar. You can either use a premixed mortar (already mixed with sand) or mix your own in a ratio of 3 parts sand to 1 part masonry cement. Add just enough water and mix to a consistency that you can make into a "mortar ball" (similar in size to a snow ball) and it will still maintain its shape. Spread mortar on top of your foundation and lay your first row of stones in the mortar bed. Next, build up the corners of the wall with the material you have saved out for that purpose. You don’t have to build the corners to the full height of the wall now, but the corners should always be higher than the middle until you reach the top. Spread mortar on top of each stone before you set the next one on top of it. As you place the next stone, mortar will squeeze out of the joint. Remove the excess with the trowel. (Later, as the mortar has begun to dry, you can come back and finish off the joints with a jointer or a brush) Now you can fill in the field between the corners of the wall. The general rules of laying stone are:

1. Lay a stone as it would rest naturally on the ground (Don’t stand them on end).
2. Avoid long horizontal joints.
3. Break all vertical joints.
4. As often as practical, lay a stone the full width of the wall (bond stone). If it is a retaining wall, this stone should go into the hill as far as possible.

For a free-standing wall, build up both faces at the same time.

For a retaining wall, fill in behind the wall as you go with a material that will drain well.

Cap the wall with the stone you have saved for that purpose.

The best way to keep the wall clean is to mix the mortar as dry as possible (see above) and then clean up with water and a sponge before the mortar has set completely. If the mortar has set and won't clean up with water, ask your supplier about methods for cleaning.

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How to Build a Dry Stacked Stone Wall

1. Tools and Materials Checklist

 

 

2. How to Figure Amount of Stone Required

We first need the volume of stone in the wall in cubic feet. To do this, determine the length and the height of the wall in feet. Then determine the thickness of the wall. The general rule of thumb for a retaining wall is that the thickness of the wall at any point should be half of the height of the wall above it. For a 4' high retaining wall, the base should be about 2' thick. The wall should then taper uniformly as it rises. If you are constructing a free-standing wall, the thickness is governed by aesthetics. The shorter the wall, the narrower it can be. For most wall stones, the minimum thickness is about 1'. For a 4' high retaining wall, the average thickness would be: (2' (at base) + 1' (at top))/2 = 1'-6"

If your wall is going to be 20' long and 4' high, the the calculation is as follows:

20' x 4' x 1'-6" = 120 Cubic Feet

Most stone is going to yield about 15 Cubic Feet per ton, so:

120 Cubic Feet = 8 Tons
15 CF/Ton

Coverage may be somewhat more or less depending on how much trimming and fitting you do.

3. How to Construct Your Wall

Next, using the stakes & string, outline the shape of your wall. Then dig out the soil to the width and length of your wall. The depth will vary. At a minimum, go down 8", but you must also remove all of the loamy topsoil down to a firm base. Fill in the trench with crushed stone to about 4" from the top of your trench. Before you start building make a pile of the flattest stone to use to cap the wall (if you are going to use a coping to finish off the top of the wall, you can skip this step). Then, make another pile with pieces that you can use for corners. Now you are ready to start with the stone. First, build up the corners of the wall with the material you have saved out for that purpose. You don't have to build the corners to the full height of the wall now, but the corners should always be higher than the middle until you  reach the top. Now you can fill in the middle between the corners of the wall. The general rules of laying stone are:

1. Lay a stone as it would rest naturally on the ground (Don't stand them on end).
2. Avoid long horizontal joints.
3. Break all vertical joints.
4. As often as practical, lay a stone the full width of the wall (bond stone). If it is a retaining wall, this stone should go into the hill as far as possible.

For a free-standing wall, build up both faces at the same time.

For a retaining wall, fill in behind the wall as you go with a material that will drain well.

Finally, cap the wall with the stone you have saved for that purpose.

As an alternate method of installation, replace the crushed stone base with concrete and then put some mortar between each stone while still keeping the mortar back from the face of the stone. This will still give you the "dry wall" look, but give the wall more stability. This installation method is especially useful for a novice.

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How to Build a Dry Stacked Stone Wall | How to Build a Motared Stone Wall