"Masonry"How To Tuck-point Bricks
Tuck Pointing Tips
Re-pointing is highly labor intensive. Although it involves small areas, the joints themselves, there may be thousand of joints over a huge expanse, requiring the erection of major scaffolding.
If you are going to do the re-pointing yourself, begin by chiseling out the damaged mortar. Remove any material that may crumble easily, using a specialized chisel available in masonry supply stores; don't hammer hard, may cause cracks in the bricks. Caution: Wear goggles for this or any work requiring the chipping or cutting of bricks.
Mix the mortar. If your old mortar was lime putty, use lime putty again or add 20% portland cement. Using too much will make the mortar harder than the brick which will lead to harmful stress in the wall. If you are concerned about matching the color of the old mortar, test your new mortar mixture first in a small area. You can change the color by adding coloring or using colored sand in the mix (which are available at the masonry stores). Colored sand is especially helpful in matching some redder mortars, but matching any one mortar can be difficult.
Clean out the joints with a hose and pressure nozzle. Lay the mortar on a flat board. Use a joint filler (a long, thin towel made especially for re-pointing) that is slightly narrower than the joint to push mortar from the board into the cleaned and wet joint. Fill the vertical joints with a small trowel. Then, after the mortar has stiffened slightly, run the trowel or a shaping tool called a jointer along the new joints to make their profile match that of the old.
You may have to replace a whole brick if it is very damaged. To do so, chisel out the mortar in the joints around the brick and then split the brick with a chisel and hammer. Clean out the hole. Cut off about 3/4-inch. of the back of a new brick so that it will fit easily into the hole. Put an ample amount of mortar into the hole and then push in the brick. Scrape away any excess mortar that has oozed out and re-point any area the mortar has not oozed to the surface.
If you need to break bricks along exact lines, use a brick hammer and a tool called a brick set, which is a broad chisel. Use the brick set and hammer to tap along the line for the cut all around the brick. Set the brick on a resilient surface such as turf or a thin bed of sand and hold the brick set to the line again. Strike it hard, and the brick should split on the line you want ( most of the time, that is -even pros mangle a few bricks using this method).
If you have a lot of bricks to cut, look into renting a brick cutter or a ceramic tile wet saw, from any tool rental facility.