How to Repoint a Brick Wall

Job: cut out failed mortar joints on an existing brick wall and pack new mortar in, so the joints shed rain again and the wall stops coming apart — chimney, garden wall, foundation face, or a whole house elevation.

Time: a small patch — a few square feet of bad joints — is an afternoon plus days of curing you mostly watch. A full elevation is a project measured in weekends: raking out is the slow, careful half, and rushing it is how good brick gets wrecked.

Difficulty: moderate hand skill, but with one genuine trap that has nothing to do with skill — using the wrong mortar. Get the mortar right and a patient amateur does lasting work. Get it wrong and a skilled job slowly destroys the wall it was meant to save. The hardest part of this job is a decision, made before you touch a tool.

The tools from this catalog:

the Dig-it™ removal tool (Hyde 43670) — the rake-out tool: two ground points dig the dead mortar up out of the joint, and the bevel shears the residue off the brick faces on push and pull. Hand-raking is the *control* method — it cannot overcut a soft brick the way a power grinder can.

the 5-1/2" and 7" Philadelphia-style pointing trowels (Hyde 18100 / 18110) — the packing tools: a small, rigid, forged blade that carries a controlled load of mortar to the joint and presses it home with tip and edge. 18100 for tight fields and fine tip control; 18110 for more mortar per trip.

the margin trowels (Hyde 18050 1-1/2" / 18060 2") — mix the pointing mortar in a pail, scrape the square corners clean, and load the hawk or board.

the brick jointer (Hyde 18170, 3/8" & 1/2") — strikes the fresh joint concave and dense at thumbprint-hard; its two half-round ends match the two standard brick-joint widths.

Everything else — and most of it this catalog does not sell, said plainly:

The mortar itself — which is the entire job, and the store does not sell it. You supply the mix: a soft, lime-rich mortar (or a bagged Type N or Type O) for older brick, plus clean sand and, usually, a little pigment to match color. Do not reach for the "strongest" bag; on the wrong wall it is a wrecking bar (see the assessment step — this is *the* decision).

The tuck pointing trowels (Hyde 18070 3/8" / 18080 1/2") — the Hyde catalog offers these, but this store line does not stock them as members. Their blade is ground to slide *inside* a standard joint, so they pack a raked joint tighter than a pointing trowel's tapered blade can. On a serious repoint they are the ideal partner to the 18100/18110 — the pointing trowel carries and presses, the tuck pointer packs in the joint.

A plugging (joint) chisel and a mason's hammer, or a joint raker — for hard mortar the hand point won't clear.

A power grinder with a proper mortar-raking wheel, a dust shroud, and a HEPA vacuum — the only safe way to power-rake long runs of hard cement joints.

A hawk or a mortar board (the finishing-trowels-and-hawks line carries hawks; this line does not), a mixing bucket and a paddle or hoe.

A stiff bristle brush to dress the joints, a spray bottle or hose for dampening and curing mist, a sponge and a clean-water bucket.

Gloves, safety glasses, and a real respirator. All three are load-bearing on this job, not boilerplate — the reasons are below.

Before you start: read the wall (this is the decision the whole job turns on)

Find the failure — and only the failure. Drag a point (the 43670) or an old key along the joints. Sound mortar pushes back; failed mortar is powdery, crumbling, cracked, or already washed hollow behind the face. Repoint the joints that have failed and a reasonable margin around them — a wall with a few soft joints does not need every joint gutted, and needless raking is needless risk to the brick. Note the pattern of failure too: joints that erode fastest low on a wall, under a leaking sill, or below a failed cap are telling you where water is getting in, and repointing without fixing that source just resets the clock.

Read the brick, because the brick chooses the mortar. This is the load-bearing decision. Older brick — soft-fired, common before roughly the 1920s and the rule on pre-1900 buildings — is *softer and more vapor-open* than modern brick, and it was laid in soft, lime-rich mortar on purpose. In that wall the mortar is the sacrificial part: it is meant to be weaker than the brick, to flex with movement, and to let the wall breathe moisture out through the joints. Pack such a wall with a hard modern mortar — Type S, or straight portland cement — and you invert that order. The joint is now harder than the brick, so building movement and freeze-thaw stress can no longer relieve through the mortar; it discharges into the brick instead, and the faces spall — flake and pop off. The dense mortar also blocks the joint's vapor path, forcing trapped moisture to escape through the brick face, where freezing and salts break it apart. The result is a "repair" that quietly demolishes the wall over a decade of winters — and you can always replace mortar, but you can never un-spall a brick. The cardinal rule, from the national preservation standard: new mortar must be no harder than the old, and softer than the masonry units — always (NPS Preservation Brief 2 — Repointing Mortar Joints in Historic Masonry Buildings). If the wall is genuinely old and you are unsure, have the original mortar analyzed, or default soft (lime-rich); the strong bag is the one mistake this job never forgives.

Note the existing joint profile — you will match it. Look at how the sound original joints were finished: concave (a half-round scoop), V, flush/struck, weathered (angled), grapevine, or beaded. The jointers in this catalog (18170 / 18182) strike concave — which happens to be the most weather-resistant profile there is, ranked best for shedding water because it compresses the mortar surface against the brick (BIA Technical Note 7B) — but a repoint that reads as a different profile than the wall around it is a scar for the life of the building. If the original is a specialty profile, you will need a slicker or a profile jointer this store does not sell; matching the original is the preservation rule, not the tool's convenience.

Know when it is not a repoint at all. Bulging or leaning courses, stair-step cracks that keep moving, a sagging lintel over a window — those are structural failures, and troweling fresh mortar over the joints hides them for a season and lets them get worse. That is a mason's or an engineer's call, not a pointing job. And even on a sound wall, don't rake many joints deep across a load-bearing wall all at once — work in controlled areas so the wall is never widely opened at the same time.

Cutting out the old joints

Rake to sound depth — and mind the brick's edges more than the mortar. With the 43670, break the dead mortar's back down the *center* of the joint with a point, then clear both faces with point and bevel until the cavity is square-backed, clean, and dust-free — a stiff brush finishes it. Depth is the credibility of the entire repair: a thin smear of new mortar over a shallow-cleaned joint pops out within a few winters. Clear the joint to at least twice its width — the preservation standard is roughly 2 to 2-1/2 times the joint width, and deeper wherever the old mortar still crumbles at the point's touch (NPS Preservation Brief 2). Rake the head (vertical) joints and the bed (horizontal) joints alike. The discipline that separates a repair from a wrecking job: never let the tool widen the joint or chew the brick arrises — the arris is the edge of the brick, which is the face of the wall; a joint cut wider than the original can never be made to look right again.

The grinder caution, stated plainly. An angle grinder with a mortar-raking wheel is fast on long runs of hard portland-cement joints — but on soft brick it is a face-wrecker: the wheel skates out of the joint and slices the arrises, and it over-cuts a soft joint before you can stop it. Reserve power raking for genuinely hard cement mortar, keep it off the brick, and only run it with a dust shroud and HEPA vacuum (next paragraph). Hand-raking with the 43670 is slower, but it is the *control* method — it physically cannot bite a soft brick the way a wheel can.

The silica boundary — this is the job's real hazard. Raking, and above all grinding, cured mortar releases respirable crystalline silica — the dust behind silicosis, an incurable, dose-driven lung disease. Grinding old masonry mortar is one of the highest-silica tasks in all of construction; OSHA sets the construction exposure limit at 50 µg/m³ averaged over a shift (29 CFR 1926.1153). Even a small hand job earns the practices: dampen the joint ahead of the point, vacuum with a HEPA vac rather than sweep, and wear a real respirator (an N95 as the floor, not the ceiling) on anything past a few joints. Your lungs get no exemption for the job being small.

Packing the new joints

Mix the mortar to match — softer than the brick — and mind the burn. This is where the assessment (Step 2) becomes a bucket of mix: lime-rich and soft for old brick, matched in color and sand texture to the surviving original so the repair disappears. Mix small and stiff — a batch the margin trowel (18050) turns in a pail is a batch that stays workable to the wall; the square corners scrape the pail's base so nothing cakes dry (the 2" 18060 turns a batch faster, the 1-1/2" 18050 chases the tight corner cleaner). And gloves on before the first load: wet mortar is strongly alkaline — pH 12 to 13 — and it burns skin caustically with no pain to warn you; a national survey found cement burns in 35% of apprentice masons (eLCOSH, Poison Control, NPCA). Repointing rides mortar against your hand all day, joint after joint — this is the trade that meets wet mortar most.

Dampen the joints first. Old, dry masonry drinks the water out of new mortar before it can cure, and mortar that cured thirsty is weak and crumbly. Mist the raked joints until the brick is damp but not streaming — damp, not soaked (standing water floats the fresh mortar back out). Let the surface sheen go before you point.

Pack in lifts, and press — never wipe. Hold a hawk or board of mortar up under the joint to catch what falls (what falls goes straight back in — mortar is money). Pick up a small ribbon on the 18100 or 18110 blade and press it into the joint with the tip and edge, compacting from the back of the cavity forward. Fill deep joints in lifts of about a quarter inch, letting each stiffen thumb-firm before the next — one greedy full-depth pass slumps, and slumped mortar never compacts, so it fails. Pack head joints and bed joints full, with no voids: a hollow you leave is a place water will sit and freeze. The 18110's extra length carries more mortar for long open runs; the 18100's 5-1/2" blade turns inside tight fields — around sash, under sills, between close headers — where the 7" can't pivot. This is exactly the work the tuck pointing trowels (18070 / 18080, catalog companions this store line doesn't stock) were made to finish: their in-joint blade packs a raked joint tighter than any tapered trowel, and a kit that pairs one with the pointing trowel points faster and cleaner.

Finishing: strike the joint, then leave it alone

Strike the joint at thumbprint-hard — matched to the original profile. The packed mortar is still soft and open; tooling compresses its surface, closes the shrinkage cracks against the brick, and sets the profile. The half-round does not carve a groove; it *compresses*, and that concave (or matched) profile is weather doctrine, not decoration. If the wall's original joints are flush, grapevine, or another specialty profile, tool to match with the right slicker — a concave repair in a flush wall is a permanent scar.

Dress the fins dry, then clean the faces — patiently. Tooling squeezes thin ridges (fins) of mortar out at the joint edges. Leave them. When they have dried crumbly — an hour or a few on — knock them off with a stiff brush stroked diagonally across the joints, then brush or lightly sponge the faces clean. Brushing or wiping fins while they are *wet* is the classic ruin: it drags cement paste across the brick and burns in a gray haze that no rinse fully forgives, and on porous historic brick it is close to permanent.

Cure slow — mist and wait. New mortar, and lime-rich mortar above all, must not dry fast: it needs water to cure to strength, and lime literally cures by drawing carbon dioxide out of the air over days. Keep the fresh joints damp — misted, or draped with damp burlap and plastic — for the first several days, out of direct sun and hard wind. A repoint cured slow outlives the mason; one flash-dried in an afternoon sun powders back out in a season.

What goes wrong (and the fix)

"The brick faces are flaking off around my new joints." The cardinal failure: you pointed soft brick with a mortar harder than the brick (portland-rich or Type S). The hard joint is forcing stress and moisture into the brick. There is no touch-up — the fix is to rake the wrong mortar back out and repoint in a soft, lime-rich mix matched to the wall (Step 2). This is exactly why the strong bag is the trap.

"The whole wall is smeared gray." You brushed fins or cleaned faces while the mortar was wet. Cut nothing wet: let fins dry crumbly, dress them dry, and clean only then. Cement haze is far easier to never make than to remove.

"The repair stands out — wrong color, wrong profile." The mortar didn't match the sand/color, or you tooled a different profile than the wall. Match both to the surviving original *before* you commit an elevation; test a small area and let it dry (mortar dries lighter than it looks wet) before doing the whole wall.

"The new mortar is popping out of the joints." You didn't rake deep enough (a shallow joint has nothing to key into — Step 5), or you filled it in one slug instead of packing lifts (Step 9), or the dry brick sucked the mortar before it cured (Step 8). All three are prep failures, not mortar failures.

"I rented a grinder and now the brick edges are chewed." The wheel climbed out of the joints onto the arrises — the risk the caution in Step 5 names. Keep power raking to hard cement mortar only, off the faces; on soft brick, hand-rake with the 43670.

This isn't a wall crack. A hairline crack in plaster, drywall, or a stucco face that you mean to fill is a different job and a different tool — the crack opener and its filler (45400, then 45450, wall-repair line), not a raked-and-packed mortar joint. Repointing excavates a *failed joint* and packs it; crack repair *opens and fills* a crack. Different grammar, different aisle.

The history footnote (because these pages should be worth reading)

The single idea this whole job turns on — soft mortar for soft brick — is a lesson the twentieth century had to relearn the hard way. When portland cement went cheap and universal after about 1900, well-meaning crews repointed countless soft old brick facades with hard cement mortar, and spalled the very buildings they were "fixing"; the U.S. National Park Service wrote its repointing standard precisely to stop the damage (NPS Preservation Brief 2). The word behind the tuck pointers in your kit is older and stranger than the repair job: true "tuck pointing" was never about repair at all. It crossed from the Low Countries into England by the early 1700s — Batty Langley's London price book was already listing it — as a *cosmetic* trick to make cheap, irregular brick look like expensive, precisely cut "gauged" brickwork: mortar tinted to the brick's own color was struck flush, a fine groove was cut into it, and a thin white ribbon of lime putty was tucked into that groove to fake a crisp, hair-thin joint (Wikipedia — Tuckpointing, The Red Mason — Historic Tuck Pointing). The trade kept the name and dropped the illusion; today "tuckpointing" and "repointing" mean the same honest repair.