How to Repair Mortar Joints

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

Fourth dimension

Multiple Days

Complexity

Beginner

Cost

Varies

Introduction

Larn the tools and techniques used for tuckpointing old masonry walls and chimneys. Find how to restore croaky and worn mortar joints, how to cut out sometime 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'due south attractive and easy to maintain. Yet over the years, water, ice and seasonal expansion and wrinkle all attack the solid mass of a brick wall at its most elastic (and weakest) bespeak: the mortar joints.

Mortar joints deteriorate wherever water can soak them—nether windows and walls, effectually chimneys, behind downspouts, at ground level and at whatever exposed wall acme.

Repairing eroding and cracked mortar joints is called pointing, repointing or tuckpointing. We'll prove you the proper tools and techniques to repair and restore cracked and worn-away mortar joints to make them solid, durable and good looking. To continue them that manner for the long run, y'all have to terminate water 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 nosotros show, you can expect to repoint most 20 sq. ft. of brick work a day. However, if you rush and do careless work on a highly visible area, the repointing brickwork will stick out like graffiti. Brick is durable; bad results volition bother you for a long fourth dimension! If yous 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 upwards 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 acquire how to repoint brick.

Project step-by-step (ix)

Step 1

Employ an Angle Grinder for Larger, Harder Repointing Brick Jobs

angle grinder repointing brick jobs mortar joints

Cleaning out onetime mortar joints requires bones 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 do tackle larger jobs or encounter hard mortar that tin't be easily chiseled out, we recommend that you hire or buy an angle grinder fitted with a diamond blade. Select a grinder with a 4-i/2 in. blade diameter; larger grinders are harder to control and cut the mortar likewise deep. To begin, Cutting grooves 3/4 to i in. deep in cracked or deteriorating mortar using a 4-ane/two in. angle grinder fitted with a diamond blade. Push button the blade into the articulation until the grinder caput contacts the brick, and make a single pass along the eye of the joints.

Stride 2

Chip Out Loose Mortar

chip out loose mortar

Break out old mortar using a hammer and cold chisel or a apartment 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. Wear prophylactic glasses and a grit mask and remove 3/4 to 1 in. of old mortar (more if needed) until y'all 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, make a relief cut downward 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, employ an bending grinder to make the relief cuts. Exercise care hither; the grinder can easily nick and chip the bricks, then don't utilise it to clean out the mortar contacting the brick. To avoid nicking the bricks, cutting the vertical joints earlier cutting the horizontal joints.

Step iii

Make clean the Joints

clean mortar joints

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

Step four

Mix the Mortar

mix the mortar

Using simply the amount of h2o specified by the manufacturer, gradually add together in the water and mix the mortar in a cement gunkhole until information technology'south the consistency of peanut butter and sticky enough to cling to an overturned trowel. Information technology should be potent but non crumbly. Allow the mortar to "rest" for 10 minutes every bit it absorbs the water, and so remix it using your brick trowel. Don't effort to revive mortar that's drying out by adding more water to it. Mix a fresh batch instead.

Step 5

Make full the Joints with Mortar

fill the joints with mortar

The basic steps for how to mortar brick get-go like this: Load mortar onto an overturned brick trowel, hold the trowel under the horizontal articulation—tight to the brick—and sweep 1/4-in. slivers of mortar into the cavity using a 3/eight-in. wide pointing trowel. Fill the horizontal joints first. Avoid getting mortar on the brick face.

Follow these boosted tips for filling mortar joints:

  • Pack the mortar tightly with no voids for the strongest, virtually water-resistant joints.
  • Fill deeper joints (those greater than iii/4 in.) in ii stages. Let the beginning layer to partially harden (until a thumbprint barely leaves an indentation) earlier calculation the 2d layer.
  • In hot conditions, piece of work in shaded areas kickoff (if possible) and then the sun won't dry the mortar too fast. Mix smaller batches of mortar.
  • Don't piece of work in temperatures below forty degrees F.

Pace 6

Fill the Vertical Joints Last

fill vertical mortar joints last

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

Step 7

Figure 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. Side by side, buy the mortar finishing tool you demand to lucifer the contour and depth of your existing mortar joints. We recommend that you repoint brick sills and other horizontal brick surfaces (ledges, wall tops, etc.) with affluent joints to promote drainage—regardless of the blazon of mortar articulation in your vertical walls. Allow 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 near common mortar joint profiles:

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

Footstep 8

Rake the Joints

rake the mortar joints

For this project, nosotros used a raked articulation mortar profile. To make your ain raked articulation tool, drive a 6d box boom into a short 1x2 board then that it matches the depth of the existing joints. To "rake" joints, concord the board perpendicular to the bricks and move it back and forth, kickoff 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

Use a soft-bristle castor to remove mortar chunks on the brick face up earlier they harden and to sweep loose mortar from the finished joints. The brush keeps the mortar from smearing. If y'all do smear mortar onto the brick, you'll have to go back later and use a chemic cleaner. Prevent water from entering and dissentious your brickwork by applying color-matched polyurethane caulk where stucco, wood and other materials encounter 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, check out How to Repair Broken Bricks.

Originally Published: June 26, 2022