How to Repair Mortar Joints

Restore aging mortar joints with a chisel, a grinder and a lot of patience

Fourth dimension

Multiple Days

Complication

Beginner

Cost

Varies

Introduction

Acquire the tools and techniques used for tuckpointing erstwhile masonry walls and chimneys. Discover how to restore cracked and worn mortar joints, how to cut out erstwhile mortar and how to pack new mortar in neatly and cleanly.

Tools Required

Materials Required

  • Mortar mix

Repair Mortar Joints

Brick is one of the most prized exteriors for homes because it's attractive and easy to maintain. Still over the years, water, ice and seasonal expansion and contraction all attack the solid mass of a brick wall at its most elastic (and weakest) point: the mortar joints.

Mortar joints deteriorate wherever water tin soak them—under windows and walls, effectually chimneys, behind downspouts, at ground level and at any exposed wall top.

Repairing eroding and cracked mortar joints is called pointing, repointing or tuckpointing. We'll evidence you the proper tools and techniques to repair and restore cracked and worn-away mortar joints to make them solid, durable and skilful looking. To continue them that way for the long run, you take to stop water from getting into your bricks and foundation.

Repointing brick is tiresome, painstaking work that requires few special skills but a lot of patience. Using the steps we bear witness, y'all can expect to repoint nigh 20 sq. ft. of brick piece of work a day. However, if you rush and do careless piece of work on a highly visible area, the repointing brickwork will stick out like graffiti. Brick is durable; bad results volition carp y'all for a long time! If yous don't have repointing brick experience, consider hiring a pro for:

  • Larger-calibration pointing jobs, such equally a whole wall that needs repair.
  • Chimney and wall repair requiring setting up and moving scaffolding.
  • Areas with a lot of loose or missing brick requiring rebuilding walls or corners.
  • Color-matching new mortar to existing mortar in highly visible areas.

Read on to larn how to repoint brick.

Project step-by-step (9)

Pace 1

Use an Angle Grinder for Larger, Harder Repointing Brick Jobs

angle grinder repointing brick jobs mortar joints

Cleaning out old mortar joints requires basic tools: hammer, flat utility chisel, safety spectacles, dust mask and whisk broom. Filling the cleaned-out joints requires masonry tools: brick trowel, three/8-in. pointing trowel, a special tool for contouring the joints and waterproof gloves.

If y'all practice tackle larger jobs or encounter difficult mortar that can't be easily chiseled out, we recommend that you lot rent or buy an angle grinder fitted with a diamond bract. Select a grinder with a 4-1/2 in. bract diameter; larger grinders are harder to control and cutting the mortar also deep. To begin, Cut grooves iii/iv to 1 in. deep in cracked or deteriorating mortar using a 4-1/2 in. angle grinder fitted with a diamond blade. Button the blade into the joint until the grinder head contacts the brick, and make a single laissez passer along the center of the joints.

Step 2

Fleck Out Loose Mortar

chip out loose mortar

Intermission out old mortar using a hammer and cold chisel or a flat utility chisel that'due south narrow enough to fit into the joints. Position a flat utility chisel at the border of the brick and drive it toward the relief cutting to fracture and remove the mortar. Wear prophylactic glasses and a dust mask and remove iii/iv to 1 in. of old mortar (more if needed) until you accomplish a solid base for bonding the new mortar. If the mortar is so soft that the bricks are loosening up, you'll accept to remove and properly reset them. If the cracked mortar is harder, make a relief cut down the center of the mortar joint using the pointed border of the chisel and so gently flake out the mortar (brick grout) that contacts the brick.

If the removal piece of work is going really slowly, use an angle grinder to make the relief cuts. Exercise care here; the grinder can easily nick and chip the bricks, so don't utilize it to clean out the mortar contacting the brick. To avoid nicking the bricks, cut the vertical joints earlier cutting the horizontal joints.

Stride 3

Make clean the Joints

clean mortar joints

One time the old mortar is removed, dust out the brick cavity joints using a whisk broom or compressed air,  Prepare the joints to receive new mortar by misting them lightly with a garden hose sprayer.

Step 4

Mix the Mortar

mix the mortar

Using only the amount of water specified past the manufacturer, gradually add together in the h2o and mix the mortar in a cement boat until information technology's the consistency of peanut butter and pasty plenty to cling to an overturned trowel. It should be stiff but non crumbly. Let the mortar to "rest" for ten minutes every bit it absorbs the water, so remix information technology using your brick trowel. Don't try to revive mortar that'southward drying out by calculation more water to information technology. Mix a fresh batch instead.

Pace 5

Make full the Joints with Mortar

fill the joints with mortar

The basic steps for how to mortar brick start like this: Load mortar onto an overturned brick trowel, agree the trowel under the horizontal joint—tight to the brick—and sweep 1/4-in. slivers of mortar into the crenel using a 3/8-in. wide pointing trowel. Fill up the horizontal joints first. Avert getting mortar on the brick face up.

Follow these additional tips for filling mortar joints:

  • Pack the mortar tightly with no voids for the strongest, nearly water-resistant joints.
  • Fill up deeper joints (those greater than 3/four in.) in ii stages. Allow the outset layer to partially harden (until a thumbprint barely leaves an indentation) before adding the 2nd layer.
  • In hot conditions, work in shaded areas first (if possible) then the sun won't dry the mortar too fast. Mix smaller batches of mortar.
  • Don't work in temperatures beneath forty degrees F.

Footstep 6

Fill the Vertical Joints Final

fill vertical mortar joints last

Load smaller amounts of mortar onto the dorsum of the brick trowel, concur the trowel tip forth the vertical joints and above the horizontal joints—tight to the brick—then sweep and pack the mortar into the cavity using the pointing trowel.

Stride 7

Figure A: Common Mortar Joint Profiles

common mortar joint profiles

Before finishing the mortar joint, determine which joint matches your existing joints using Figure A above. Next, buy the mortar finishing tool you lot demand to match the profile and depth of your existing mortar joints. We recommend that you repoint brick sills and other horizontal brick surfaces (ledges, wall tops, etc.) with flush joints to promote drainage—regardless of the type of mortar articulation in your vertical walls. Permit the mortar to cure to "thumbprint" hardness before you finish the joint. Shape the vertical joints before working the long horizontal joints. These are the most common mortar articulation profiles:

  • Raked joint: Formed by removing mortar to 1/4 in. deep with a raking block.
  • 5-Joint: Formed by a brick jointer, it has a concave, "5" expect.
  • Affluent articulation: Formed by cutting off the mortar with the edge of a brick trowel.
  • Concave joint: Formed by the curved end of a brick jointer.

Pace 8

Rake the Joints

rake the mortar joints

For this projection, we used a raked joint mortar profile. To make your own raked joint tool, bulldoze a 6d box blast into a short 1x2 board so that it matches the depth of the existing joints. To "rake" joints, hold the board perpendicular to the bricks and motion information technology back and forth, first along the vertical joints so the horizontal joints. Other joint profiles require other shaping tools.

Step 9

Clean the Bricks

clean bricks mortar joints

Employ a soft-bristle castor to remove mortar chunks on the brick face before they harden and to sweep loose mortar from the finished joints. The castor keeps the mortar from smearing. If you practice smear mortar onto the brick, you lot'll take to get back later and use a chemical cleaner. Prevent water from entering and damaging your brickwork past applying color-matched polyurethane caulk where stucco, forest and other materials see brick. Mist the new mortar twice a day for two days using a hand pump sprayer or a low-cal mist from a garden hose to help it harden.

Plus, bank check out How to Repair Broken Bricks.

Originally Published: June 26, 2022