Brick Repointing on Cape Cod: Lime Mortar and Salt Air

Brick repointing on Cape Cod is the job of raking out mortar that salt air, wind driven rain and freeze and thaw have turned to sand, and packing the joints with new mortar that is softer than the brick around it. Done right, it stops water getting into a chimney, a set of front steps or a foundation wall and buys that brick decades more life. Done with the wrong mortar, it wrecks the brick it was meant to save. Coast Carpentry Home Group repoints brick across the Cape from our shop at 14 Parker Rd, Unit A in Osterville.

Most Cape houses are shingle houses, so the brick here is concentrated where the weather is worst: chimneys above the roofline, front steps and walks, foundation piers and the odd brick ell on an older village street. This guide covers how we read a failing joint, what mortar belongs on old Cape brick, what the work involves, why brick steps heave in our sand, and the honest line between a repoint and a rebuild. No prices here. A real number takes a look at the joints up close.

Why does brick fail at the joints first on Cape Cod?

Brick and mortar are a team, and the mortar is meant to lose. A good joint is a little softer and more porous than the brick, so it takes the movement, takes the water and gives up its face first. You repoint a joint every few decades instead of replacing brick every century.

The Cape makes the mortar lose faster. Salt spray comes a long way inland on a southwest breeze, and salt in a mortar joint pulls moisture in and keeps it there. Our winters rarely stay frozen. They hover around freezing and cross it over and over, so water in a joint freezes, expands, thaws and soaks deeper, week after week from December into March. A chimney standing above the roof in the full wind, or front steps facing the street and the weather, are the two places we are called to most.

We see it in a predictable order. The exposed top of a chimney goes first, then the weather side of a wall, then the joints at grade where snow sits and melts. The street side of a brick stoop in Hyannis, Falmouth or Sandwich village is usually sandy to the touch years before the back of the same stoop shows anything. Our overview of Cape Cod masonry in a coastal climate covers why the same forces hit stone and concrete differently.

How do you tell if brick needs repointing?

Start with the key test. Drag a car key along a joint. Sound mortar scratches a line and stays put. Failed mortar sheds sand and the key sinks. Then look at depth. Joints that have weathered back more than a quarter inch from the face are holding water in a little shelf every time it rains, and that water has nowhere to go but in.

Hairline cracks between the mortar and the brick, not in the brick, are a repointing sign. So is white staining on the brick face, which is salt the water carried out of the wall. Inside the house, a damp patch on plaster beside a chimney breast after a nor’easter is very often open joints on the outside of that chimney, not a roof leak, and we cover how to tell those two apart in our guide to chimney repair on Cape Cod.

Three things are not a repointing job. A crack running in a stair step pattern through several courses is movement in the structure below. A wall or chimney that bulges, leans or has a brick you can wiggle has lost its bond. Brick whose face has popped off in flakes was damaged by water that froze behind a hard mortar. Those get a different conversation, further down this page.

What mortar should be used to repoint old Cape Cod brick?

This is the part most repointing jobs get wrong, and the damage takes a few winters to show. Old Cape brick, the soft red brick in the chimneys and foundations of nineteenth century houses along Route 6A and in the village centers, was laid in lime mortar. Lime mortar is soft, it breathes, and it moves a little with the seasons. Repoint that brick with a hard, dense cement mortar and you have made the joint stronger than the brick. Now the brick is the weak part. Water that used to leave through the joint stays in the brick, freezes, and pops the face off. We have raked out 1980s cement repoints on 1880s chimneys where the joints were fine and every brick behind them was spalled.

The rule we work by is the one the National Park Service lays out in its repointing brief: the new mortar is weaker than the masonry and no harder than the original mortar. For soft old brick that means a lime based mortar, Type O at the hardest. For brick from the 1950s onward, which is harder and fired more evenly, Type N is right for anything above grade. Type S has its place in a retaining wall footing or a block foundation, and nowhere near a chimney top.

Color and texture matter as much as strength on a house people can see from the road. We match the sand, not just the pigment, because the sand is what you see once the surface weathers. We make up a sample joint, let it cure a week and compare it dry before touching the rest of the wall. Our post on brick versus stone for the Cape climate goes deeper on which materials belong where.

What does the repointing process actually involve?

Depth is everything. Mortar bonds to brick, not to old mortar, so a joint has to be opened until there is clean brick on both sides for the new mortar to grab. On a standard joint that is three quarters of an inch at the very least, and deeper where the old mortar is loose further in. A skim of new mortar smeared over the old face looks finished for a season and falls out in a year. We rake by hand with a chisel on soft old brick, because a grinder in a hurry takes the arris off every brick it passes. A thin diamond blade is fine for the long bed joints on hard modern brick, never for the short head joints.

Then the joint is blown free of dust and rinsed, which also takes off the salt crust that would otherwise sit behind the new mortar, and the brick is dampened so it does not suck the water out of the fresh mix. That dry, dusty mortar you can rub out with a thumb is what happens when this step is skipped.

We pack the mortar in lifts, a quarter inch or so at a time, each compacted before the next. When it is thumbprint hard it gets tooled to match what was there, flush, weathered, concave or whatever profile the house was built with, because a new profile changes the look of a wall more than owners expect.

Curing is where Cape weather sets the calendar. Mortar needs to stay damp for days to gain strength, and above freezing through that stretch. We mist the work, shade a south facing wall in July, and we do not point a chimney in a January cold snap without tenting and heating it. Most of our repointing runs April through November.

Why do brick steps and walkways heave on the Cape, and does repointing fix them?

Mortared brick front steps are the most common brick repair call we get after chimneys, and the owner usually asks for repointing because the joints have opened. The joints opened because the steps moved. Many Cape steps sit on a few inches of concrete poured onto whatever sand was there, with no footing below frost. Every winter frost lifts them and every spring they settle somewhere slightly different. The mortar cracks because it is the only part that cannot flex.

Repointing those joints without fixing the base is money spent on a problem that comes back the next March, and we tell owners that plainly. The honest repair is to take the brick up, salvage what is sound, build a base that will not move, and relay and point the steps once. The same logic runs through our guide to paver patio installation on Cape Cod, where the base, not the paver, decides whether it stays flat.

Brick walks set in sand are a different animal. They are meant to move a little, and a wavy sand set walk is relaid and re-sanded, not repointed. The mortared brick caps on retaining walls take the same freeze and thaw beating from the top, which is why the cap detail gets its own section in our post on retaining wall installation on Cape Cod.

When is brick past saving?

Repointing is the right answer most of the time, and we would rather save old brick than replace it. There is a line, though, and crossing it with a repoint wastes the owner’s money. When the faces have popped off a third of the bricks on a chimney’s weather side, new mortar between damaged bricks just holds water against more damaged brick. When a brick crumbles under a tap of the hammer, no joint will save it. When the top courses of a chimney rock when pushed, that chimney gets taken down to sound brick and relaid.

Movement is the other line. Stepped cracking through a foundation wall or a brick ell means the ground under it moved, on the Cape usually water in sand or a footing that was never below frost. Repoint that crack and it will reopen. Finding the water and fixing the footing is the job, and pointing is the last step, not the first.

Where a rebuild makes sense, old brick salvages well. Lime mortar cleans off a brick with a hammer and a chisel, which is one more reason the right mortar matters. Brick set in hard cement usually breaks before the mortar lets go. Our post on masonry work in Hyannis covers the rebuild side, where village chimneys and old foundation walls are a steady part of the work.

What does a brick mason on Cape Cod do that a general handyman cannot?

Repointing looks simple from the street, which is why it is often done badly. The skill is in the judgment, not the trowel. A mason who has opened enough Cape joints knows by the color of the dust whether the original mortar was lime or cement, and that one call decides whether the repair protects the brick or destroys it. The same mason knows that a damp patch beside a chimney in a Yarmouth cape is sometimes the step flashing and not the joints.

Coast Carpentry Home Group runs masonry crews alongside our roofing and carpentry crews, which is worth something on a chimney job. The same visit that repoints the stack can reset the counter flashing into the new joints and replace the cap, instead of one trade pointing around flashing another trade will tear out next spring. Fagner Rodrigues holds the Massachusetts Construction Supervisor license that every Coast job runs under, the crew brings more than 25 years of experience to the brick, and every repoint we do carries our lifetime workmanship warranty.

If you are comparing masons, our guide to choosing a masonry contractor on Cape Cod lists the questions to ask, including the one about mortar type that separates the people who know old brick from the people who own a grinder. Our masonry repair on Cape Cod page lists everything the crew handles, from chimneys to steps to stone.

Do you need a permit or historic review to repoint brick on Cape Cod?

Repointing with matching mortar is repair, and towns treat it that way. The moment the work becomes a rebuild, taking a chimney down below the roofline or relaying a foundation wall, it is a building permit pulled under a licensed contractor. We pull the permits on our own jobs and tell owners up front which side of that line their work falls on.

Historic review is the Cape wrinkle. From Sandwich to Orleans, the Old King’s Highway Regional Historic District covers the land north of Route 6, and Falmouth, Barnstable and other towns have local historic districts of their own. Those committees review exterior changes visible from a public way. A like for like repoint is not a change. A chimney that was pointed with a soft gray flush joint and comes back with a bright white raked joint is a change, and the kind a neighbor photographs. Match what was there and the question never comes up. Our post on masonry styles in historic Cape homes covers the broader subject.

What drives the cost of brick repointing on Cape Cod?

Square footage of wall is the least useful number. Two chimneys the same size can be very different jobs. One has hard modern brick with joints that rake cleanly with a blade and point with Type N from the bag. The other has soft 1890s brick that has to be raked by hand, a lime mortar matched in color and sand, a dozen spalled bricks to cut out and replace with salvaged matches, and staging around a steep roof. The second one costs more.

Access and season are the other drivers. A foundation wall at grade is quick to work on. A chimney above a steep roof means staging, roof protection and a slower day, and a late season job that needs tenting and heat costs more than the same work in June.

We do not put repointing prices on this page because an honest number needs a look at the joints and a count of the damaged brick. Ask us to come look, and you will get a written scope that says what gets raked, what mortar goes back in, what gets replaced and what it will cost.

Coast Carpentry Home Group is BBB Accredited with an A+ rating and Google Guaranteed. Our reviews come from homeowners across Barnstable County, and our Cape Cod masonry services page shows the rest of what the crew does.

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