Rock Wall Mortar and Repair

Tools:

safety glasses
dust mask
gloves
plastic measuring container
water bucket
brick hammer
kneepads
sponge
garden trowel
trowel
wooden craft sticks
air gun (or hairdryer)
wire brushes
tub
vacuum cleaner
cement
lime
dark sand
light sand
water

1. Clean off stones and remove loose mortar from the wall and the back sides of the stones (figure A). Lightly tap the areas to be repaired with the brick hammer to check for loose masonry. Don't worry about removing large chunks of mortar that are firmly attached.

2. Vacuum away dust and debris. Use a trowel to probe around in cracks and crevices while vacuuming out the area (figure B).

3. Mix up a batch of mortar using cement, lime, light and/or dark sand and water. The ratio may vary from area to area, so check with some local masons about what ratio you should use. In this project, the mortar was mixed using a cement / lime / sand ratio of 1 to 1 to 6, plus water.

4. Thoroughly mix the dry ingredients, then make a depression in the center and pour in some water (figure C). Mix well and add more water until the mortar is the consistency of oatmeal. Let the mortar set or "slake" for 10 minutes.

6. Wet existing stone wall with sponge so the stones are good and moist. The dampness will prevent the stones from leaching too much water from the new mortar, which will lead to more cracks.

7. Fill in areas using the trowel and replace stones. Use a wooden craft stick to fill in small areas and sculpt the mortar (figure E).