How to Repair Mortar Joints

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

Time

Multiple Days

Complexity

Beginner

Cost

Varies

Introduction

Larn the tools and techniques used for tuckpointing old masonry walls and chimneys. Discover how to restore croaky and worn mortar joints, how to cut out old 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. Yet over the years, water, ice and seasonal expansion and contraction all attack the solid mass of a brick wall at its near rubberband (and weakest) point: the mortar joints.

Mortar joints deteriorate wherever water can soak them—under windows and walls, around chimneys, behind downspouts, at ground level and at any exposed wall meridian.

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

Repointing brick is boring, painstaking work that requires few special skills but a lot of patience. Using the steps we show, you lot tin expect to repoint about twenty sq. ft. of brick work a twenty-four hours. All the same, if you blitz and practice devil-may-care work on a highly visible area, the repointing brickwork volition stick out like graffiti. Brick is durable; bad results will carp you for a long fourth dimension! If you don't accept repointing brick feel, consider hiring a pro for:

  • Larger-scale 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-stride (9)

Step 1

Apply 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, dust mask and whisk broom. Filling the cleaned-out joints requires masonry tools: brick trowel, iii/viii-in. pointing trowel, a special tool for contouring the joints and waterproof gloves.

If you exercise tackle larger jobs or encounter hard mortar that can't be easily chiseled out, we recommend that yous rent or purchase an angle grinder fitted with a diamond blade. Select a grinder with a four-1/2 in. blade bore; larger grinders are harder to control and cut the mortar too deep. To brainstorm, Cutting grooves 3/4 to 1 in. deep in cracked or deteriorating mortar using a 4-1/2 in. angle grinder fitted with a diamond blade. Push the blade into the joint until the grinder caput contacts the brick, and make a single pass forth the eye of the joints.

Step two

Chip Out Loose Mortar

chip out loose mortar

Break out onetime mortar using a hammer and cold chisel or a flat utility chisel that's narrow enough to fit into the joints. Position a flat utility chisel at the edge of the brick and drive it toward the relief cut to fracture and remove the mortar. Vesture safety glasses and a grit mask and remove 3/iv to 1 in. of one-time mortar (more if needed) until y'all reach a solid base of operations for bonding the new mortar. If the mortar is and then soft that the bricks are loosening up, y'all'll have 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 edge of the chisel and then gently chip out the mortar (brick grout) that contacts the brick.

If the removal work is going really slowly, utilize an angle grinder to make the relief cuts. Exercise care here; the grinder tin easily nick and chip the bricks, and then 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 three

Clean the Joints

clean mortar joints

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

Footstep 4

Mix the Mortar

mix the mortar

Using merely the amount of water specified past the manufacturer, gradually add in the h2o and mix the mortar in a cement boat until information technology's the consistency of peanut butter and sticky enough to cling to an overturned trowel. It should be stiff merely not crumbly. Let the mortar to "residue" for 10 minutes equally it absorbs the water, then remix information technology using your brick trowel. Don't try to revive mortar that's drying out by calculation more than water to it. Mix a fresh batch instead.

Step 5

Fill the Joints with Mortar

fill the joints with mortar

The bones steps for how to mortar brick start like this: Load mortar onto an overturned brick trowel, concord 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. wide pointing trowel. Fill the horizontal joints starting time. Avoid 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, most water-resistant joints.
  • Fill up deeper joints (those greater than 3/4 in.) in two stages. Allow the outset layer to partially harden (until a thumbprint barely leaves an indentation) before adding the second layer.
  • In hot weather, work in shaded areas kickoff (if possible) so the sunday won't dry the mortar as well fast. Mix smaller batches of mortar.
  • Don't work in temperatures below forty degrees F.

Step 6

Fill the Vertical Joints Last

fill vertical mortar joints last

Load smaller amounts of mortar onto the back of the brick trowel, concur the trowel tip along the vertical joints and in a higher place the horizontal joints—tight to the brick—and then sweep and pack the mortar into the cavity using the pointing trowel.

Stride 7

Figure A: Mutual Mortar Articulation Profiles

common mortar joint profiles

Before finishing the mortar articulation, determine which articulation matches your existing joints using Figure A to a higher place. Next, purchase the mortar finishing tool yous need to lucifer 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 joint in your vertical walls. Allow the mortar to cure to "thumbprint" hardness earlier you lot finish the joint. Shape the vertical joints before working the long horizontal joints. These are the about common mortar joint profiles:

  • Raked joint: Formed by removing mortar to 1/iv in. deep with a raking block.
  • V-Joint: Formed past a brick jointer, it has a concave, "Five" look.
  • Flush joint: Formed by cutting off the mortar with the border of a brick trowel.
  • Concave joint: Formed by the curved cease of a brick jointer.

Pace 8

Rake the Joints

rake the mortar joints

For this project, we used a raked articulation mortar contour. To brand your own raked joint tool, drive a 6d box nail into a brusque 1x2 board so that information technology matches the depth of the existing joints. To "rake" joints, hold the lath perpendicular to the bricks and movement information technology back and along, first along the vertical joints and so the horizontal joints. Other joint profiles require other shaping tools.

Step 9

Clean the Bricks

clean bricks mortar joints

Utilize a soft-bristle brush to remove mortar chunks on the brick face earlier they harden and to sweep loose mortar from the finished joints. The castor keeps the mortar from smearing. If yous do smear mortar onto the brick, y'all'll have to go back later on and use a chemic cleaner. Preclude water from entering and damaging your brickwork by applying color-matched polyurethane caulk where stucco, wood and other materials meet brick. Mist the new mortar twice a day for two days using a paw pump sprayer or a lite mist from a garden hose to help it harden.

Plus, check out How to Repair Broken Bricks.

Originally Published: June 26, 2022