How to Repair Mortar Joints

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

Time

Multiple Days

Complexity

Beginner

Cost

Varies

Introduction

Acquire the tools and techniques used for tuckpointing onetime masonry walls and chimneys. Observe how to restore cracked 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'due south bonny and like shooting fish in a barrel to maintain. All the same over the years, water, ice and seasonal expansion and contraction all attack the solid mass of a brick wall at its about elastic (and weakest) betoken: the mortar joints.

Mortar joints deteriorate wherever h2o tin soak them—under windows and walls, around chimneys, behind downspouts, at ground level and at any exposed wall tiptop.

Repairing eroding and cracked mortar joints is chosen pointing, repointing or tuckpointing. We'll show yous 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 tiresome, painstaking work that requires few special skills simply a lot of patience. Using the steps we show, you lot can wait to repoint about 20 sq. ft. of brick work a mean solar 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 will carp you lot for a long time! If yous don't have repointing brick experience, 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.
  • Colour-matching new mortar to existing mortar in highly visible areas.

Read on to larn how to repoint brick.

Projection step-by-pace (9)

Step one

Use an Angle Grinder for Larger, Harder Repointing Brick Jobs

angle grinder repointing brick jobs mortar joints

Cleaning out sometime 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, 3/8-in. pointing trowel, a special tool for contouring the joints and waterproof gloves.

If you lot do tackle larger jobs or run into difficult mortar that can't be hands chiseled out, we recommend that you lot rent or buy an angle grinder fitted with a diamond blade. Select a grinder with a 4-1/ii in. blade bore; larger grinders are harder to control and cut the mortar too deep. To begin, Cutting grooves 3/iv to 1 in. deep in cracked or deteriorating mortar using a 4-1/2 in. angle grinder fitted with a diamond blade. Push button the blade into the joint until the grinder caput contacts the brick, and make a single pass forth the center of the joints.

Pace 2

Bit Out Loose Mortar

chip out loose mortar

Intermission out old 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 border of the brick and drive it toward the relief cut to fracture and remove the mortar. Clothing safety glasses and a grit mask and remove 3/four to ane in. of one-time mortar (more if needed) until you attain 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 heart of the mortar joint using the pointed edge of the chisel so gently scrap out the mortar (brick grout) that contacts the brick.

If the removal work is going really slowly, use an bending grinder to make the relief cuts. Exercise care here; the grinder tin can hands nick and chip the bricks, so don't use it to clean out the mortar contacting the brick. To avert nicking the bricks, cutting the vertical joints earlier cutting the horizontal joints.

Step three

Clean the Joints

clean mortar joints

Once the quondam 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.

Footstep 4

Mix the Mortar

mix the mortar

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

Step five

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 crenel using a iii/8-in. broad pointing trowel. Make full the horizontal joints commencement. 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, about water-resistant joints.
  • Fill deeper joints (those greater than 3/4 in.) in 2 stages. Allow the first layer to partially harden (until a thumbprint barely leaves an indentation) before calculation the second layer.
  • In hot weather, piece of work in shaded areas showtime (if possible) so the lord's day won't dry the mortar as well fast. Mix smaller batches of mortar.
  • Don't work in temperatures beneath 40 degrees F.

Step 6

Fill up the Vertical Joints Last

fill vertical mortar joints last

Load smaller amounts of mortar onto the back of the brick trowel, hold the trowel tip forth the vertical joints and higher up the horizontal joints—tight to the brick—then sweep and pack the mortar into the cavity using the pointing trowel.

Footstep vii

Figure A: Common Mortar Articulation Profiles

common mortar joint profiles

Earlier finishing the mortar joint, determine which joint matches your existing joints using Figure A above. Next, buy the mortar finishing tool you need to match 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 flush joints to promote drainage—regardless of the blazon of mortar articulation in your vertical walls. Allow the mortar to cure to "thumbprint" hardness before y'all finish 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 joint: Formed by cutting off the mortar with the edge of a brick trowel.
  • Concave joint: Formed by the curved end of a brick jointer.

Step 8

Rake the Joints

rake the mortar joints

For this project, we used a raked joint mortar profile. To make your ain raked joint tool, drive a 6d box blast into a short 1x2 lath so that it matches the depth of the existing joints. To "rake" joints, concord the board perpendicular to the bricks and move information technology back and forth, first forth the vertical joints and then the horizontal joints. Other joint profiles crave other shaping tools.

Step 9

Clean the Bricks

clean bricks mortar joints

Use 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, y'all'll have to go back afterward and use a chemical cleaner. Prevent water from entering and dissentious your brickwork by applying color-matched polyurethane caulk where stucco, wood and other materials meet brick. Mist the new mortar twice a day for ii days using a paw pump sprayer or a lite mist from a garden hose to help it harden.

Plus, bank check out How to Repair Broken Bricks.

Originally Published: June 26, 2022