Category Archives: Brick Mason

Why Brick Masonry Needs Control Joints on Long Exterior Walls

Madison Brick & Stone Posted on by
Brick masonry control joints shown along a long exterior brick wall to accommodate movement and help prevent random cracking.

Brick masonry looks like the most solid part of any building, and it still moves. A brick wall changes size during the day, across the seasons, and slowly over its first few years. On a short wall nobody notices. On a wall that runs sixty or eighty feet, that change adds up, and the wall builds stress it has to let go of somewhere. Control joints decide where. Leave them out and the wall picks the spot itself, usually with a crack in the worst place.

Movement Is a Normal Part of Every Brick Wall

Heat causes the movement most people can picture. Brick warms in the sun and grows a little. It cools at night and pulls back. That cycle repeats every clear day for the life of the building. A wall facing the afternoon sun swings more than a shaded wall on the same house.

Moisture causes the movement almost nobody expects. Clay brick comes out of the kiln bone dry, then starts pulling humidity out of the air right away. That makes each brick grow. Most of the growth happens in the first few years, and it never goes back. So a long brick wall ends up slightly longer than the day it was built. Settlement adds a third source. Foundations press down a bit as a building takes on its full weight, and any uneven movement below travels up into the brick. None of this is a defect. It’s just what brick does.

Control Joints Direct Stress Where It Belongs

A control joint is a planned vertical break in the brick. It stays open instead of being packed with mortar. The brick on each side can shift toward the gap and away from it, so the units never press hard against each other. The joint doesn’t stop the movement. It gives the movement a safe place to happen.

What goes inside the joint matters as much as the gap. A soft backer material sits in the space and squeezes when the wall grows, then springs back when it shrinks. A flexible sealant closes the face so water stays out while still stretching. Both parts have to stay soft. Filling a joint with mortar, which happens a lot during repairs, turns the break back into solid wall. Then the stress goes looking for a weak point. It usually finds a corner, a window head, or a spot a few feet from the end of the run, and that’s where the crack shows up.

Wall Layout Influences Joint Placement

Spacing follows the shape of the building, not one fixed number. Long runs of unbroken brick usually get a joint every twenty to thirty feet. Sun changes that, since a wall in full sun moves more than a shaded one and may need joints closer together on the same building.

Windows change the picture too. A wall with lots of openings has less solid brick to build up movement, but the brick beside and above those openings is also the weakest part of the wall. So joints often belong near them, not just in the blank stretches. Corners are the classic trouble spot. Two walls push toward the same corner and neither one gives, which is why so many buildings show vertical cracks a few feet in from an outside corner. Changes in wall height, like a step in a parapet, and changes in thickness do the same thing. All of this belongs on the drawings during design. Picking joint locations on the scaffold, after courses are already up, puts them where they fit instead of where the wall needs them.

Coordination With Other Building Materials Matters

Brick rarely runs across a whole wall by itself. It meets concrete, steel angles and lintels, stone, and window and door frames. Each of those materials reacts to weather in its own way. Concrete shrinks as it cures and then mostly holds still. Steel moves with heat but not with humidity. Concrete block behind the brick shrinks while the brick in front of it grows. The two layers of the same wall are moving opposite directions.

That has to be detailed, not ignored. Brick sitting on a steel shelf angle needs a soft joint underneath so it can grow without pressing on the steel. Windows and doors need sealant joints sized for the movement expected there, not a bead of caulk applied by eye. Where brick meets stone or another material, the joint has to take movement from both sides. A break that stops partway through an assembly just moves the problem, so joints in nearby materials should line up with the brick joints when the design allows. These meeting points are where most movement damage actually starts.

Regular Inspections Help Maintain Performance

The sealant in a control joint wears out. It sits in the sun and rain and flexes constantly, and over time it hardens, shrinks and pulls away from one edge. Most sealants last somewhere between ten and twenty years depending on the product and how much weather that wall takes. Every brick building has a sealant replacement in its future.

An inspection should cover more than the joints. Sealant that looks chalky, cracked or separated needs replacing before the next wet season. Mortar joints, flashing and weep holes belong in the same walk around, since a failed joint often shows up first as water somewhere odd. Cracks near corners or over windows deserve a closer look, because they can mean a joint failed or was never put in. Any joint filled with mortar during an old repair should be cut out and rebuilt properly. Buildings checked every few years spend a little on sealant. Buildings left alone pay for water damage and masonry work instead.

Brick Repair for Stair-Step Cracks Around Windows and Doors

Madison Brick & Stone Posted on by
Professional brick mason inspecting stair-step cracks around a window on a brick home in Madison, Alabama to identify the cause before repair.

Every crack in your brick shows up somewhere specific. Almost never in the middle of a blank wall. Almost always at a corner of a window or a door.

That’s not coincidence, and it’s the first thing a good brick repair starts with. While some situations eventually require brick replacement, the real priority is identifying why the wall moved in the first place. Openings are where a wall is weakest, so they’re where movement announces itself first. The crack didn’t pick that spot at random.

Here’s the takeaway. The stair-step crack at your window corner is a symptom with a cause, and repairing the brick without finding that cause means paying for the same crack twice.

Windows and Doors Are the Weakest Interruptions in a Brick Wall

A brick wall works as one continuous unit. Load spreads sideways through the courses and down to the foundation, so a solid wall shares stress across a wide path. That sharing is what makes masonry strong.

Cut a hole in it and that path breaks. Load has to travel around the opening instead of through it, which concentrates stress at the four corners. Those corners are now carrying more than their share.

Openings also change how the wall moves. Brick expands and contracts with temperature and moisture, and a solid wall does that evenly. A wall full of windows moves unevenly, since the sections between openings are narrow and the sections above are supported by something other than brick.

So when anything shifts below or behind the wall, the corners go first. They’re the concentration points, and cracking is how they release.

Stair-Step Cracks Follow the Mortar Because It’s Designed to Give First

Mortar is the weaker material by design, so a crack takes the easiest path through the wall. That path runs along the joints rather than through the brick.

The staircase shape is just geometry. A crack moving diagonally has to alternate between horizontal bed joints and vertical head joints, since those are the only continuous weak lines available. It steps because the brick pattern forces it to.

That shape tells you something useful. Stair-step cracking means one part of the wall moved relative to another part, and the crack is tracing the boundary between them. If a crack runs straight through the brick faces instead of around them, the force involved was strong enough to beat the brick, and that changes the conversation.

The Direction of the Crack Often Points Toward the Cause

Start with where the crack begins and which way it travels. Successful brick crack repair starts by understanding that pattern, since the direction of the crack often reveals what caused the movement in the first place. Cracks tend to open widest at the end furthest from whatever is holding still, so the wide end points away from the stable ground.

A stair-step crack running down and outward from a lower window corner usually says settlement. Something under that part of the wall dropped, and the wall above followed, tearing at the weakest corner. The width at the bottom tells you roughly how far.

A crack running upward and outward from an upper corner often says the opposite. That section lifted or the section beside it dropped. Either way, differential movement between two parts of the same wall.

Watch for cracks paired with displacement at the top of an opening. Steel lintels above windows and doors rust, and rusting steel swells with real force. Cracks radiating from both upper corners, especially with the brick above pushed outward, points at the lintel rather than the ground.

Thermal movement has its own signature. It shows as thin cracks that open in winter and close in summer, usually at the same locations year after year. That crack is annoying rather than dangerous, and treating it like settlement wastes money.

Not Every Stair-Step Crack Needs the Same Repair

The crack doesn’t decide the repair. The cause does.

Repointing works when the movement has stopped and the brick is sound. A mason rakes out the cracked joints and packs in compatible mortar, which restores the joint without touching brick. That’s the cheapest outcome and it’s real when the conditions are right.

Brick replacement enters when individual bricks cracked through or spalled. Sound brick around a failed one gets left alone, since every brick removed disturbs its neighbors. Good masons take out as few as the job allows.

Lintel repair is a different job entirely. Fixing rusted steel means supporting the brick above, removing or treating the lintel and rebuilding. Repointing a lintel crack accomplishes nothing, because the steel keeps swelling underneath your new mortar.

Structural stabilization comes when the ground is the problem. Foundation work happens first, and masonry follows. A mason who offers to fix settlement cracking with mortar is selling you a delay.

Lasting Repairs Focus on Movement Before Masonry

The question that decides everything is whether the wall is still moving. Everything else follows from the answer.

Masons check it a few ways. Crack width gets measured and marked so it can be re-read later, and monitoring over a season separates active movement from an old scar. Fresh, clean crack faces suggest recent movement. Dirty, weathered faces suggest something that happened years ago and stopped.

Active movement means repair waits. Pack mortar into a crack that’s still opening and it fails in the same line, usually within a year or two. That repair looked perfect for one winter and cost you the price of doing it twice.

Sequence is the whole thing. Find the cause, stop it, then rebuild. Any other order is cosmetics with an invoice attached.

Frequently Asked Questions

Why do stair-step cracks usually form around windows and doors?

Windows and doors interrupt the wall’s continuous load path, concentrating stress at their corners. When the structure shifts, these areas are often the first places where stair-step cracks appear.

Why do stair-step cracks follow the mortar joints instead of the bricks?

Mortar is intentionally softer than brick, so it becomes the path of least resistance when movement occurs. Cracks that pass directly through the brick itself often indicate greater structural stress.

Can stair-step cracks be repaired by repointing the mortar alone?

Only if the underlying movement has stopped. Repointing a wall that is still shifting usually results in the same crack returning because the root cause remains unresolved.

How can I tell if a failing lintel is causing the crack?

Cracks that begin at the upper corners of a window or door, combined with displaced bricks or widening mortar joints above the opening, can indicate a deteriorating steel lintel that needs further inspection.

Should I repair a stair-step crack right away or monitor it first?

It depends on whether the crack is still active. A professional may recommend monitoring the crack over time to determine if movement has stopped before performing permanent masonry repairs.

Why a Brick Mason Checks Mortar Joints Before Major Repairs

Madison Brick & Stone Posted on by
Professional brick mason inspecting mortar joints on a brick home in Madison, Alabama before recommending masonry repairs.

Somebody quotes you a brick repair. They walk the wall, count the damaged brick and hand you a number. Nobody scratched a joint with a key.

Walk away. A brick mason who hasn’t read the mortar doesn’t know what’s wrong with your wall yet, and the mortar is where the answer lives. Whether the solution is brick repointing or a more extensive repair depends on what those mortar joints reveal. It’s a thin gray line most people never look at, and it decides whether your repair lasts thirty years or cracks again next winter.

Mortar is the part of your wall designed to fail. How it’s failing tells a mason what the wall actually needs. Skip that step and you can make a sound wall worse.

Mortar Is Designed to Wear Out Before the Brick

Mortar is sacrificial, and that means something specific. It’s intentionally the weaker material, so when the wall moves or water gets in, the mortar gives way instead of the brick.

That design saves you money. Joints are replaceable, and a mason can rake out old mortar and pack in new without touching a single brick. Brick isn’t replaceable the same way, since removing it disturbs everything around it.

Softness does real work too. Walls move with temperature, moisture and load, and a soft joint absorbs that movement. A rigid joint refuses, so the stress goes into the brick instead.

So a crumbling joint isn’t automatically bad news. Sometimes it’s a fifty-year-old material doing exactly what it was hired to do.

Healthy Mortar Ages Predictably. Failed Mortar Doesn’t.

Normal weathering is even and slow. The joint face erodes back a little and goes slightly chalky, and it happens across the whole wall at the same rate. Scratch it and you find firm material a quarter inch in.

Accelerated deterioration looks different, and location is the tell. Mortar failing in one band or one elevation while the rest is fine points at a cause, not at age. Something is delivering water or stress to that spot.

Depth matters too. Joints you can push a key into past your fingernail have lost their grip on the brick. At that point the joint isn’t transferring load anymore.

Watch for mortar that comes out as sand. Healthy old mortar crumbles into chunks. Powder means the binder is gone, and that’s usually water working for years.

Matching New Mortar to Old Masonry Is More Important Than People Think

Mortar isn’t one product. Type N and Type O are softer. Type S and Type M are hard, and hard is where people get in trouble.

The instinct is that stronger equals better. It’s wrong, and it’s the most damaging mistake in brick repair. New mortar must be softer than the brick and no harder than what it replaces, or you’ve changed how the whole wall behaves.

Older brick makes this worse. Brick made before modern kilns is often softer and more porous than anything sold today. Pack a hard modern mix into that wall and the joint becomes the strongest thing in it.

Permeability is the other half. Mortar is meant to let moisture pass through and evaporate, which is a drying path built into the wall. A dense mix seals that path shut.

Repairing Brick Before Understanding Mortar Can Lock Moisture Inside the Wall

Water gets into every masonry wall. That’s normal and always has been. What matters is whether it can get back out.

Block the joints with hard mortar and water still comes in, since joints were never the only entry. Now it has to leave through the brick face, carrying salts and pressure with it. That’s the only route you left open.

Freeze-thaw finishes the job. Trapped water expands when it freezes and pops the brick face off in flakes. You’ll see it as spalling right along a repointed section, and homeowners blame the brick every time.

Look at any old building with a stripe of ruined brick beside sound brick. That stripe is where somebody repointed with the wrong mix twenty years ago. The repair is still there. The brick is gone.

Mortar Condition Often Determines Whether Repairs Stay Fixed

Reading joints first tells a mason three things. Whether water is getting in, where it’s getting in, and whether the wall is still moving.

Each answer changes the job. Water intrusion means fixing the source first, since new joints in a wet wall fail the same way the old ones did. Movement means finding out whether it stopped, because repointing a moving wall just relocates the crack.

Compatibility decides longevity. A joint matched to the brick shares stress and passes moisture the way the wall was built to, and it lasts decades. A mismatched joint starts damaging brick from the day it cures.

The cheapest quote skips all of it. Somebody grinds out joints, packs in whatever bag is on the truck and leaves. It looks correct for about two winters.

What to Ask Before Anyone Grinds a Joint

  1. What mortar type are you using, and how did you pick it against my brick?
  2. Is my brick soft or hard, and how do you know?
  3. Where is water getting into this wall, and have you found the source?
  4. Is the mortar failing evenly, or only in certain areas?
  5. Is the wall still moving, and should we wait?

Anyone who answers “stronger mortar” to the first question is telling you where your next repair will be.

Frequently Asked Questions

Why is mortar intentionally softer than brick?

Mortar is designed to act as the sacrificial part of a masonry wall. It absorbs movement and weathering so the mortar joints can be repaired more easily than the bricks themselves.

Can the wrong mortar mix damage brick?

Yes. Mortar that is too hard can trap moisture and resist normal movement, causing the surrounding brick to crack, chip, or deteriorate over time.

What are the signs that mortar joints are failing?

Mortar joints may be failing if they crumble easily, recede deeply between the bricks, develop widespread cracking, or deteriorate unevenly across the wall. These patterns often point to moisture or structural movement rather than normal aging.

Why does a brick mason inspect mortar before repairing brick?

The condition of the mortar helps identify hidden issues such as water intrusion, ongoing movement, or drainage problems. Understanding these conditions allows the mason to recommend the most effective repair instead of simply replacing damaged bricks.

Does older brick require a different type of mortar?

Often, yes. Older brick is typically softer and more porous than modern brick, so it performs best with a compatible mortar that allows the wall to breathe and move naturally without damaging the masonry.