Tuckpointing 101: How to Remove Old Mortar Joints Cleanly with an Angle Grinder

Why Crumbling Mortar Joints Can't Wait

Crumbling mortar joints are more than a cosmetic issue. Once the joint face is open, water gets in — and in winter, freeze-thaw cycles will literally blast your masonry apart from the inside. Before you can repoint a brick wall, the old, failing mortar has to come out: to a consistent depth, and without chewing up the edges of the surrounding brick.

This guide walks you through choosing the right grinding tool for the job and the step-by-step process pros use to rake out joints cleanly.

Choosing Your Tool: Two Options for Raking Out Joints

Option 1: Diamond Tuckpointing Wheel

A diamond tuckpointing (crack chaser) wheel mounts on a standard angle grinder and grinds out the joint with a diamond-coated rim.

  • Size: Typically 4-1/2" to 5" (115–125 mm) wheels
  • Best for: Rock-hard Portland cement joints, large wall areas, continuous production work
  • Cutting widths: 1/4" to 3/8" (6–10 mm) covers most standard joint patterns

Option 2: Carbide Grout Cutter with 5/8"-11 Thread

A carbide mortar-raking bit threads directly onto the 5/8"-11 spindle of your angle grinder — no flange nuts, no wrench needed.

Not sure whether your grinder takes a 5/8"-11 threaded tool or a standard arbor blade? Our guide to diamond blade arbor sizes and the 5/8"-11 thread explains how to check in 30 seconds.

  • Mounting: Screws straight onto the grinder's 5/8"-11 arbor
  • Best for: Lime mortar, softer historic joints, spot repairs and smaller patch jobs
  • Advantage: You can choose how much of the working length to engage, which gives you fine control over joint depth

For lime-based and softer mortars, the PRODIAMANT Carbide Grout Cutter is purpose-built for exactly this: it fits any 5/8"-11 angle grinder and clears joints fast without gouging the brick.

Step by Step: Raking Out Mortar Joints the Right Way

  1. Set your target depth. The rule of thumb: rake the joint out to a depth of twice the joint width. A 3/8" (10 mm) joint gets cleared to about 3/4" (20 mm) deep. That gives the new mortar enough bearing surface to key in properly.
  2. Stay centered in the joint. Guide the tool down the middle of the joint — never ride along the brick faces. Nicked or rounded brick edges are permanent and they ruin the look of the finished repoint.
  3. Do the bed joints (horizontal) first. Work all the long horizontal joints across the wall section before anything else.
  4. Then clean out the head joints. Go back and rake the short vertical joints between bricks.
  5. Clear the debris. Knock out remaining crumbs with a joint raker or plugging chisel, or blow the joints out with compressed air.
  6. Pre-wet before repointing. Dampen the raked joints before you pack in new mortar — dry, thirsty masonry sucks the water out of fresh mortar and weakens the bond.

Dust Control and Safety: Take Silica Seriously

Grinding out mortar produces an enormous amount of mineral dust — and that dust contains respirable crystalline silica. Under OSHA's silica rule (29 CFR 1926.1153), grinding masonry requires engineered dust controls, not just a dust mask and good intentions.

For the exact Table 1 requirements — CFM per inch of wheel diameter, HEPA filtration, and the stricter respirator rules for tuckpointing — see our full guide to dust shrouds and OSHA silica requirements for angle grinders.

  • Use a dust shroud with a vacuum. A grinder dust shroud connected to a HEPA-filtered vac is the Table 1 compliant setup for tuckpointing — and as a bonus, you can actually see the joint you're cutting.
  • Wear a NIOSH-approved respirator. At minimum an N95, depending on your exposure assessment.
  • Protect your eyes. ANSI Z87.1-rated safety glasses or goggles are non-negotiable when grinding masonry.

Better dust control isn't just about compliance — visibility on the joint line is what keeps your cuts centered and your brick edges intact.

Before you start grinding, run through our 10 angle grinder safety rules for cutting and grinding — mortar raking puts lateral load on the tool, and setup mistakes are where injuries happen.