Brick is a commonly used material for home exteriors, chimneys and walls, along with many other surfaces. Brick is a very long-lasting and durable building product. Unfortunately, the mortar used in between the bricks is not as tough and hardwearing. Mortar is prone to cracking and crumbling. When damage occurs to the mortar joints, repair and replacement becomes necessary. If the damaged mortar is not repaired or replaced, water will seep into the home causing structural issues. Some of the problems that can occur are wood rot, mildew growth or toxic black mold growth. Tuck pointing new or old brick mortar utilizes the same techniques.
For many years homeowners called upon masons and bricklayers to repair the mortar lines on their walls. There really is no need for a professional. Many do it yourself type homeowners are more than able to complete this fairly easy repair with the right tools and a little bit of knowledge.
Removing Old Mortar
Remove the old cracked, crumbled, flaking and otherwise damage joint. Use your finger to pick old mortar out of the lines.
Progress to wire brushing loose or crumbled mortar. You can wire brush by hand or equip a power drill with a wire brush attachment to speed the job up.
Finally use a masonry cold chisel to chip old mortar away. Hold the cold chisel held at a 45-degree angle towards the damaged area and strike with a hammer. Begin about one to two inches on an undamaged section.
If you are comfortable with power tools, you can cut the old joints out with an angle grinder equipped with a masonry wheel.
Use the wire brush to clean out bits of stuck on mortar from the bricks.
Continue to chip out the old mortar until the joint is free of mortar.
Adding New Mortar
Mix new mortar with water in a bucket to form a thick pasty consistency.
Pour the wet mortar into a grout bag.
Wet the bricks and void joint lines with plain water. Use a spray bottle or a garden hose with the nozzle set to mist. New mortar requires a damp base, not saturated, just damp. If you add mortar to dry bricks, the bricks will pull the moisture out of the mortar and cause the new mortar to crack, flake and crumble.
Place the tip of the grout bag into the joint line and squeeze it along in between the bricks. Keep a steady, even pressure while squeezing to avoid globs or mortar from being expressed on the bricks rather than in between.
Continue to fill the empty joints with new mortar until you've filled all of the joints.
Use a pointing trowel, which is a smaller version of a trowel. Pointing trowels are available with various types of edges ranging from a "V" to a concave edge.
Place the appropriate, matching edge of the pointing trowel up against the wet mortar and strike with a hammer to create the same design as in the existing mortar.
If you are tuck pointing all new mortar, point the mortar after each course of bricks in order for it to look uniform.
Pointing after each course is done because if you wait, more than likely the mortar will have dried enough so the tuck point cannot be set.
Finishing the Job
After all new mortar sits in the mortar lines, spray the new mortar with water from a spray bottle evry time it looks as if the mortar is dry for the next four or five days.
Keeping the moratr and surrounding bricks slightly damp creates a stronger mortar joint because it won't crack, crumble or flake as readily.