Brick spalls when something inside the face pushes harder than the brick can hold. Usually that something is water, either freezing or carrying salts that crystallize, and it is often made worse by hard mortar, a coating that traps moisture, or a brick that was never very durable. Impact can do it too. Freezing alone is not always the cause.
Spalling brick is one of the most common reasons homeowners call about older walls. True Course Masonry Newark replaces spalled brick and fixes the conditions behind it across Newark and Essex County, with the work carried out by licensed and insured contractors, and the business takes small jobs of a few bricks as well as larger ones. This guide explains each cause, how to tell them apart from the ground, and how the cause changes the repair on the brick repair service.
Water, freezing and the brick face
Fired clay brick is porous. It soaks up rain, holds it in the outer inch or so, and dries out through its face and through the mortar joints. A brick that is only damp has empty pore space for ice to expand into. A brick that stays saturated does not, and when water freezes it expands by roughly 9 percent, so the pressure lands on the pore walls just behind the face. Repeat that enough times and the face lets go.
Newark gives a wet wall plenty of chances to freeze. NOAA’s 1991 to 2020 normals for the Newark Liberty International Airport station record 10.54 inches of precipitation in December through February alone, 31.5 inches of snow a year and about 21.5 winter days with an inch or more of snow on the ground. Snow piled against a wall melts into the bottom courses on every sunny afternoon. Roughly 65 days a year have a low at or below freezing and a high above it, a NOAA-derived proxy rather than a measured cycle count. The masonry most at risk is whatever stays wettest: brick under a dripping gutter, below a cracked coping or sill, at grade, and on chimneys and parapets exposed on every side.
That is why spalling clusters. A whole wall of the same brick in the same weather rarely spalls evenly; the damage gathers where the water does.
Salt crystallizing under the face
Salts dissolve in the water moving through masonry and crystallize where it evaporates. At the surface, that shows up as white efflorescence and does little harm. When the drying front sits just under the face, crystals grow inside the pores instead. This is subflorescence, sometimes called cryptoflorescence, and the Brick Industry Association’s Technical Note 23A notes that salts crystallizing within masonry can develop pressures large enough to spall brick.
Salt sources near a Newark wall include deicing salt on stoops, steps and sidewalks, salts in old mortar and backup masonry, and floodwater. New Jersey Department of Transportation reports put state-highway salt use from about 82,000 to 390,000 tons a winter between 2017 and 2023; those are statewide highway figures, but the same chemistry works on a salted walk next to a house. In the Ironbound, homes soaked by brackish Passaic River water during Superstorm Sandy took on salt that can keep surfacing. Spalling that comes with heavy white deposits suggests salt is part of the story; the efflorescence guide covers what the deposits mean.
Hard mortar forcing water into the brick
In an older wall the mortar is supposed to be the softer, more permeable part, so water dries out through the joints and the joints wear first. Repoint that wall with a dense, cement-rich mortar and the joints stop breathing. Water now leaves through the brick faces, carrying salts with it, and the brick edges take the freezing and crystallization pressure. The telltale pattern is spalling along the edges of bricks next to joints that stand proud and hard, sometimes with the face gone and a ridge of mortar left behind.
Homeowners report a version of this on attached rowhouses: one house spalling while its neighbors, built of the same brick at the same time, are fine. The difference is often in what each owner did later, such as a hard repointing or abrasive cleaning on one house only. The lime mortar vs portland cement guide explains the compatibility rules.
Coatings that trap moisture
Paint, film-forming sealers and cement coatings slow the outward drying that a solid brick wall depends on. Water still gets in at joints, cracks, copings and sills, then reaches the back of the coating and stops. The Brick Industry Association notes that salts can then deposit just behind a coating, about an eighth to a quarter inch below the surface, which is exactly where the face breaks off. Spalling that shows up in sheets under peeling paint or a sealer usually belongs to this category. The should you seal brick guide explains when a breathable repellent is reasonable and when a coating does harm.
Weak brick, past cleaning and impact
Some brick was simply soft. Older bricks fired at lower temperatures, or from the edges of a kiln, absorb more water and spall sooner even in a well-kept wall, which shows as scattered individual bricks failing among sound ones. Sandblasting and aggressive pressure washing strip the hard fired skin and leave the softer body exposed; the cleaning brick without damage guide covers gentler methods. Impact from a car, a ladder or a falling branch chips faces mechanically, usually in one spot with no water pattern at all.
Reading the pattern on your wall
| What you see | Points toward | Check next |
|---|---|---|
| Single bricks scattered across a wall | Soft or under-fired units | Brick hardness and absorption; matching replacements |
| A band of spalling under a gutter, sill or coping | Concentrated water plus freezing | The water source above |
| Spalling at grade, with white deposits | Splashback, snow and salt | Grade, downspouts, deicing habits |
| Brick edges gone, hard joints standing proud | Hard repointing mortar | Mortar hardness; earlier repair dates |
| Sheets of face under paint or sealer | Trapped moisture and subflorescence | Coating type; where water enters |
| One chipped spot, no wetting pattern | Impact | Whether surrounding brick is sound |
A pattern is a lead, not a verdict. Two causes often work together, such as hard mortar on a wall that also takes gutter overflow.
How urgent is it?
Look at it soon, and keep people clear, if:
- spalling is above a doorway, walkway or sidewalk, or on a chimney or parapet, where pieces can fall
- whole bricks are loose, cracked through, or shifting
- spalling sits next to a bulge, an offset crack, or rust stains over a window
- damage is clearly spreading from one winter to the next
Usually plan rather than rush when:
- a few shallow spalls sit low on the wall and are not spreading
- the brick around them is hard and sound
- the water source is obvious and can be fixed
Do not climb to or pry at loose brick yourself.
How the cause changes the repair
Replacing spalled brick means cutting out the damaged units without harming the ones around them, setting matched replacements in a compatible mortar and tooling the joints to match. That part is the same whatever the cause. What changes is the rest of the scope. Concentrated water calls for fixing the gutter, coping, sill or grade. Hard mortar may call for repointing the surrounding area in a softer mix, done carefully so the hard joints come out without breaking more brick. A coating may need to come off, by a method tested first. The brick pointing page covers the joint work, and masonry repair covers broader water and wall problems.
Homewyse’s estimator for Newark ZIP 07102 puts a one-brick repair at about $211 to $276 and roughly 10 bricks at about $530 to $660, because setup and minimum labor dominate small jobs. Those are budgeting figures, not a quote; matching old brick, height and access all move the number, as the brick repair cost guide explains.
Before you call
Stand back from the wall and photograph the spalled area along with whatever is above it, then note which way the wall faces, whether it has been repointed or painted, and how the damage has changed since last year. Those details narrow the cause faster than a close-up alone. Send them through the contact page, or run through the masonry damage assessment first.