How to Repair Mortar Joints

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

Time

Multiple Days

Complexity

Beginner

Toll

Varies

Introduction

Acquire the tools and techniques used for tuckpointing quondam masonry walls and chimneys. Detect how to restore croaky and worn mortar joints, how to cut out onetime 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 considering it's attractive and easy to maintain. Yet over the years, h2o, ice and seasonal expansion and contraction all assault 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, around chimneys, behind downspouts, at ground level and at whatever exposed wall tiptop.

Repairing eroding and croaky mortar joints is called pointing, repointing or tuckpointing. We'll show you lot the proper tools and techniques to repair and restore cracked and worn-away mortar joints to make them solid, durable and good looking. To keep them that way for the long run, you have to stop h2o from getting into your bricks and foundation.

Repointing brick is slow, painstaking work that requires few special skills but a lot of patience. Using the steps nosotros show, yous tin expect to repoint nigh 20 sq. ft. of brick piece of work a mean solar day. Still, if you blitz and do careless piece of work on a highly visible area, the repointing brickwork will stick out like graffiti. Brick is durable; bad results will bother you for a long time! If you don't accept repointing brick feel, consider hiring a pro for:

  • Larger-scale pointing jobs, such every bit 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 learn how to repoint brick.

Projection step-by-step (9)

Step one

Utilise 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 glasses, grit mask and whisk broom. Filling the cleaned-out joints requires masonry tools: brick trowel, 3/8-in. pointing trowel, a special tool for contouring the joints and waterproof gloves.

If you lot practice tackle larger jobs or see hard mortar that can't be easily chiseled out, we recommend that y'all rent or buy an angle grinder fitted with a diamond blade. Select a grinder with a four-ane/2 in. blade diameter; larger grinders are harder to command and cut the mortar likewise deep. To begin, Cut grooves 3/4 to 1 in. deep in cracked or deteriorating mortar using a iv-1/2 in. angle grinder fitted with a diamond bract. Push button the bract into the joint until the grinder head contacts the brick, and brand a single pass along the center of the joints.

Pace 2

Chip Out Loose Mortar

chip out loose mortar

Intermission out erstwhile mortar using a hammer and common cold chisel or a flat utility chisel that'southward narrow plenty to fit into the joints. Position a apartment utility chisel at the edge of the brick and drive it toward the relief cutting to fracture and remove the mortar. Wearable safety spectacles and a dust mask and remove three/four to 1 in. of erstwhile mortar (more than if needed) until you reach a solid base for bonding the new mortar. If the mortar is so soft that the bricks are loosening up, you lot'll have to remove and properly reset them. If the cracked mortar is harder, brand a relief cut downwards the center of the mortar joint using the pointed edge of the chisel and then gently flake out the mortar (brick grout) that contacts the brick.

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

Step 3

Clean the Joints

clean mortar joints

Once 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.

Stride 4

Mix the Mortar

mix the mortar

Using only the corporeality of water specified past the manufacturer, gradually add in the water and mix the mortar in a cement boat until it'southward the consistency of peanut butter and sticky plenty to cling to an overturned trowel. Information technology should be stiff but not crumbly. Permit the mortar to "rest" for ten minutes as it absorbs the h2o, so remix it using your brick trowel. Don't try to revive mortar that'due south drying out by adding more h2o to it. Mix a fresh batch instead.

Footstep 5

Fill 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, hold the trowel under the horizontal joint—tight to the brick—and sweep 1/4-in. slivers of mortar into the cavity using a 3/8-in. broad pointing trowel. Fill up the horizontal joints kickoff. Avert getting mortar on the brick face.

Follow these additional tips for filling mortar joints:

  • Pack the mortar tightly with no voids for the strongest, most water-resistant joints.
  • Fill deeper joints (those greater than 3/four in.) in two stages. Allow the first layer to partially harden (until a thumbprint barely leaves an indentation) before adding the second layer.
  • In hot conditions, piece of work in shaded areas start (if possible) so the sun won't dry the mortar too fast. Mix smaller batches of mortar.
  • Don't work in temperatures below 40 degrees F.

Stride 6

Make full the Vertical Joints Terminal

fill vertical mortar joints last

Load smaller amounts of mortar onto the back of the brick trowel, concord the trowel tip along 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.

Step vii

Effigy A: Common Mortar Joint Profiles

common mortar joint profiles

Before finishing the mortar articulation, determine which joint matches your existing joints using Figure A above. Next, buy the mortar finishing tool y'all need to match the contour and depth of your existing mortar joints. Nosotros recommend that you repoint brick sills and other horizontal brick surfaces (ledges, wall tops, etc.) with flush joints to promote drainage—regardless of the blazon of mortar joint in your vertical walls. Let the mortar to cure to "thumbprint" hardness before you terminate the joint. Shape the vertical joints before working the long horizontal joints. These are the nearly common mortar joint profiles:

  • Raked joint: Formed by removing mortar to 1/4 in. deep with a raking block.
  • V-Joint: Formed past a brick jointer, it has a concave, "V" look.
  • Flush 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.

Stride eight

Rake the Joints

rake the mortar joints

For this project, nosotros used a raked joint mortar profile. To make your ain raked joint tool, bulldoze a 6d box nail into a short 1x2 lath and then that it matches the depth of the existing joints. To "rake" joints, hold the lath perpendicular to the bricks and movement it back and forth, first forth the vertical joints and then the horizontal joints. Other joint profiles require other shaping tools.

Step ix

Clean the Bricks

clean bricks mortar joints

Apply a soft-bristle brush to remove mortar chunks on the brick face before they harden and to sweep loose mortar from the finished joints. The brush keeps the mortar from smearing. If you do smear mortar onto the brick, you'll take to get back subsequently and utilise a chemical cleaner. Prevent water from inbound and damaging your brickwork by applying color-matched polyurethane caulk where stucco, wood and other materials encounter brick. Mist the new mortar twice a mean solar day for two days using a hand pump sprayer or a calorie-free mist from a garden hose to assistance it harden.

Plus, check out How to Repair Broken Bricks.

Originally Published: June 26, 2022