Fixing the mortar joints and cracks in stone masonry is also known as re-pointing, or tuck-pointing. An unrepaired joint or crack in stone or brick foundations can result in more severe problems down the road. Since the base settles, the rest of the home settles using the changes at the base, which can manifest in plaster cracks, or doors and windows being difficult to open or close correctly. Once you properly repair cracks in stone masonry, you also can slow the consequences of the settling.
Cracks in Stone Masonry
Wash the crack using a wire brush. Eliminate any bigger loose particles using a chisel and hammer as required. Don safety glasses and a dust mask. Blow the debris out using the compressor attachment of an air compressor hose to eliminate any fine particles from the crack.
Use a pointed trowel to thoroughly fill the washed crack with vinyl concrete patcher stained to match the shade of the stone masonry. Fill the crack into the surface of the masonry, and then scrape away any excess using the trowel.
Permit the stain to dry for 24 hours, then sand the filler with medium-grit seams to mix the stain to match the surrounding stone.
Cracks at Mortar Joints
Wash the cracked mortar joint using a wire brush. Eliminate any bigger loose particles using a chisel and hammer as required, eliminating to (but no more than) one-third of the thickness of the mortar joint. Blow the debris out using the compressor attachment of an air compressor hose to eliminate any fine particles from the crack.
Pour a bag of mortar into a mixing bathtub or steel wheelbarrow. Add half of the water called to the bag’s mixing instructions, and thoroughly mix the mortar with a trowel until the mortar could be mixed to a sandstone ball that holds its shape.
Permit the mortar to sit down for one hour, then blend in just enough water to make the mortar pliable but still stiff.
Wet the damaged mortar joint with a bucket of water and a brush. Tightly pack the joint using a layer of mortar 1/4-inch thick from the border of the present mortar, with a tuck pointer. Tightly push the mortar tightly to the joint to eliminate any air bubbles, then add additional 1/4-inch layers until the joint is packed fully into the leading edge of the stone.
Permit the new mortar to sit down for 30 minutes, then drag a masonry jointer along the border of the joint to smooth out the mortar.
Brush the mortar joints using a brush to wash any excess mortar from the joints.