Repair that crumbling mortar, so you won’t have to put another brick in the wall
Brick may be one of the strongest building materials on the market, but it’s still susceptible to wear and tear. Changes in temperature coupled with moisture in the brick cause the mortar to crack and crumble over time.
Ignore this damage, and water will soon find its way into those gaps between the bricks, causing even more problems. While you can hire a brick mason near you to return a brick wall or fireplace to its former glory, consider taking on this project yourself. Make these repairs on your own and save money by learning how to tuckpoint brick using the steps below.
Tuckpointing is the process of removing crumbling mortar from the joints between bricks or stone and replacing it with fresh mortar.
The process accomplishes several things. It improves the aesthetics of the brick and the structural integrity of the chimney or wall. Tuckpointing also reestablishes a water barrier that keeps moisture from seeping into the gaps between the bricks.
Tuckpointing is messy, creating large amounts of dust and chunks of mortar, so you’ll need to prep the area by laying down a ground cloth to catch all of the debris this process will create. This dust is also dangerous to breathe in and can irritate your eyes, so you’ll also want to use a dust mask and goggles.
Before you can start repairing the damaged mortar, you’ll need to remove the loose pieces first. While an angle grinder works best, you can also use a hammer and chisel to remove the mortar.
Whether using a chisel or grinder, remove the mortar carefully to avoid chipping the brick. Position the chisel at the edge of the brick and direct it inwards toward the mortar.
If using a grinder, grind along the edge of the mortar where it meets the brick, being careful not to cut into the brick. A good rule of thumb is to observe the debris coming off the grinder. If the dust you're producing is red, you’re cutting into brick.
Chisel or grind the mortar to a depth of about 3/4 of an inch deep from the surface of the brick to create a solid base on which to spread the new mortar.
Before you can add the new mortar, you’ll first need to clean out all the debris you just finished grinding or chipping away. Sweep the mortar out of the joints using a damp stiff bristle brush.
Wash out the joints with water to ensure all the dust is removed. Don’t pour water on the wall, which will create a mess. Instead, dip a brush in the bucket then apply water to the seams. The water will remove any lingering dust while dampening the bricks, prepping them for the new mortar.
Mix the dry mortar with water, making sure to follow the manufacturer’s instructions carefully. If you’re tinting the mortar to match the color of the existing mortar, add the dye before adding the water.
While you can use a masonry trowel to mix the mortar, a better option is to use a mixer attachment with a power drill. The mixer and drill combo will allow you to achieve a smoother consistency while saving your arm.
Once mixed, the mortar should have the consistency of creamy peanut butter. Add more water or mix to get the right consistency. If you’re worried the mortar is too thin, use the trowel test. Put some mortar on the trowel, then hold it at a 45-degree angle. If the mortar is the right consistency, it will stick to the trowel.
Once the mortar is mixed, work quickly. You’ll have up to an hour to use the mortar, after which it will become too dry to use. You also may need to mix in water periodically during that period to maintain that perfect peanut butter consistency.
Begin by filling the horizontal cracks. Load a drop of mortar onto a 12-inch by 12-inch square piece of plywood or a mortar hawk. Hold the wood or mortar hawk against one of the cracks. Use a tuckpointer to push mortar into the crack until it’s flush with the brick then remove any excess mortar and add it back to wood or mortar hawk.
While you can use a grout or mortar bag to push mortar into the cracks, brick masons generally agree that mortar packed in using the above method creates a more durable joint.
Next, load mortar onto the tuckpointer and pack it into the open vertical joints. As with the horizontal cracks, make sure to pack it in before scraping off any excess.
After about 30 minutes the mortar should begin to set. Press on the mortar with a finger. You should be able to make an impression without your finger going too deep. Be wary not to let the mortar get too firm or it will be more difficult to tool.
Use a pointing trowel to create a finished edge on the mortar joints that matches the shape of the existing mortar joints.
For concave rounded joints, place the jointer at the top of vertical joints and pull it downward. For horizontal joints, run the jointer across the mortar, stopping halfway across each brick. Move the tool to the other side of the brick and run the jointer back across the joint to finish the edge.
If you want flat joints, use a joint raker. Set the rake depth using existing mortar on the wall, then run it over the new joints to flatten them out.
Wait an additional 30 minutes then use the stiff bristle brush to remove any loose particles of mortar or any mortar that is left on the face of the brick. Don’t wait too long. If the mortar is allowed to set on the brick face, you’ll need to use trisodium phosphate, a powerful acid, to get it off.
Mist the mortar with water periodically for the next several days to slow the curing process. If the area you’re repairing is small enough, hang plastic over it to help retain moisture. While this may be a pain, if the mortar is allowed to dry too quickly, it may pull away from the brick and existing mortar.
You stand to save a significant amount of money by completing a tuckpointing repair on your own. The price range for mortar repair is $10 to $20 per square foot. Repairing a small 20-square-foot section of wall will cost you between $300 and $500.
You’ll only spend about $20 for materials to complete this job yourself. Keep in mind that you will need to spend additional money on masonry tools if you don’t already own them.
The best temperature range for tuckpointing is between 40 and 90 degrees Fahrenheit, which is the range needed for the mortar to set properly. The temperature should be somewhere in this range 24 hours prior to application and 72 hours following. You should also make sure there is no rain or snow a full day prior to tuckpointing and at least a few hours after.
Though both tuckpointing and repointing involve repairing the mortar between brick and stone, there are differences between the two techniques. Repointing involves restoring a brick wall or fireplace by chipping out all of the old mortar to a depth of about 1 inch using a chisel then replacing it with new mortar.
With tuckpointing, you’re repairing and refilling damaged points in the mortar joints between the bricks. Since you are preserving undamaged mortar when tuckpointing, you usually need to use a dye to match the color of the new mortar to the existing mortar.
If you don’t tuckpoint a stone or brick wall when the masonry needs it, the mortar will continue to deteriorate to the point where the wall will become structurally unsound. At that point, the only way to repair the brick wall will be to completely tear it down and relay the brick.
