Stucco rarely fails on its own. It cracks because something behind it moved, or because water found a way in and froze there. We repair the cracking, rebuild the sections that have let go, and fix the reason it happened, using the same in-house Red Seal crews that work the rest of your building envelope.
Almost every stucco crack in this city traces back to movement or to water, and Calgary supplies both in quantity. Stucco is a rigid cement skin stretched over a wall that is not rigid at all. When the framing and the foundation behind it expand, contract or settle, that stress has to go somewhere, and it goes into a crack. From that point the crack becomes the entry. Rain and melt water get behind the face, sit there, freeze overnight and expand, and lever the same crack a little wider every cycle. That loop is what turns a hairline nobody would have worried about into a piece of stucco sitting on the lawn four or five winters later.
Water that works into a hairline expands as it freezes and prises the opening wider. Calgary runs that cycle over and over through a single season, so a crack left open one winter is rarely the same width the next spring.
A forty degree change inside one day makes the wall assembly behind the stucco move quickly. The rigid face on the outside cannot follow at the same rate, and the stress concentrates where it always does, at corners and openings.
Much of Calgary sits on clay-heavy soil that swells when it takes on water and shrinks as it dries out. That movement travels up through the foundation and the framing, and the wall finish is simply where it finally becomes visible.
Stucco hides its problems well, which is exactly why so much of it gets left until a section lets go. Walk each elevation after the spring melt and again in late fall. Pay particular attention to the corners of windows and doors, where movement concentrates, and to the bottom metre of wall, where splash-back and snow load do their work.
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Filling a crack is the easy part, and it is where most stucco patching stops. If the water is arriving from a failed roof-to-wall detail, from sealant that gave up around a window, or from a downspout emptying against the base of the wall, the same crack reopens in a season or two and the homeowner concludes that stucco repair does not work. Because our in-house Red Seal crews handle the roof, the flashings, the trim and the drainage as well as the wall itself, we can find where the water is genuinely coming from before anything gets mixed. Backed by COR safety certification and $10M liability coverage.
One crack above a window, a whole elevation that has started crazing, or a section that has already come away from the wall. Every repair carried out in-house by our certified team.
We open the crack back to sound material rather than smearing filler across the top of it, key the edges so the patch has something to hold onto, and fill with a cement-based mix rather than a tube of caulk that will telegraph through any finish coat later.
Where the surface has crumbled, blown out or been knocked off by hail, we remove the failed area, check the lath and the moisture barrier sitting behind it, and rebuild the section in coats the way it was originally built.
The part homeowners actually care about. We work the finish coat to the texture already on your wall, whether that is a knockdown, a sand float, a dash or an older hand-troweled pattern, and we feather the repair out past its own edge so the transition is not a hard line.
A crack is usually a symptom. We trace where the water is arriving from, whether that is a failed roof-to-wall detail, missing sealant at a window, or a downspout emptying against the base of the wall, and correct it before the repair goes in.
Direction, width and location tell you most of it. Cosmetic cracking wanders, stays fine, and tends to appear as a pattern across a broad area. A structural crack runs in a purposeful line, is wide enough to catch a fingernail, and starts at a corner of an opening or at a change in the wall plane, because that is where load and movement concentrate. Two other tests matter as much as the crack itself. Tap the wall and listen for a hollow sound, which means the stucco has separated from the lath behind it. Then check whether the same line shows up inside the house, at a door that has started sticking or a drywall corner that keeps reopening. If it does, the wall is moving and the stucco is only reporting it.
A crack leaving a window or door corner at an angle is following stress, not shrinkage. A pattern with no clear direction, spread across a whole wall, is usually the surface behaving normally as it ages.
Knock along the wall with your knuckles. A solid, dull note means the stucco is still bonded. A hollow, drum-like note means it has let go behind the face and a surface patch will not hold it.
Sticking doors, drywall corners that keep reopening and floors that have gone out of level are the same movement seen from indoors. When the outside and the inside agree, the wall needs looking at, not just the finish.
These are the checks we run on site, not a substitute for them. Where the movement points to something structural we say so plainly and tell you what needs assessing first, rather than selling you a repair that will not last.
Nearly every stucco problem in Calgary falls into one of three groups, and the right response is completely different for each. Here is what separates them, what each one is telling you about the wall, and how we honestly approach the repair.
Usually cosmetic
Fine lines, often in a spider-web pattern spread evenly across a wall, most of them narrower than the edge of a coin. This is what stucco does as it cures and as the wall behind it moves a little with the seasons. It is not a structural warning on its own. It does still matter, because every one of those lines is an opening water can sit in and freeze in, which is how a cosmetic pattern turns into a real one over a few Calgary winters.
Investigate first
Wider cracks that run in a definite direction rather than wandering, most often diagonally out of the top or bottom corner of a window or a door. They tell you the wall behind the stucco has moved, and in this city that usually traces back to clay soil swelling and shrinking under the foundation. Patching one of these without understanding the movement behind it buys a season or two, and then the same line comes back in the same place.
Water already in
Chunks broken away, a surface that crumbles under a thumbnail, or a wall that sounds hollow and drummy when you tap it. That hollow sound means the stucco has let go of the lath behind it. Water has already been getting in, freezing and pushing the layers apart, and the damage is no longer confined to the face. This one does not stabilise on its own and it gets meaningfully larger every winter it is left.
Walls often show more than one of these at once, which is why we assess the whole elevation rather than quoting on the crack you happened to notice from the driveway. Hail is the wildcard here, since it chips and pockmarks the face without leaving a crack at all.
Most cracked stucco is repairable, and the honest answer is that a full re-stucco is needed far less often than homeowners fear. If the stucco is still bonded to the lath and the damage is limited to cracking or a few broken areas, it is a repair. If large areas sound hollow, the moisture barrier behind has failed, or the wall has been patched so many times it is a map of previous repairs, then rebuilding the elevation is the cheaper decision over any real timeframe. The distinction is worth insisting on, because plenty of stucco gets torn off when it only ever needed cutting back and rebuilding in patches, and plenty gets patched for a fifth time when the wall behind it was finished years ago.
Cracking on an otherwise solid wall, a few chipped or spalled areas, hail pockmarks, or a single opening that has moved. The stucco is still holding onto the wall and only the face needs work.
Scattered hollow patches, an elevation carrying several generations of visible patching, or cracking that keeps returning in the same place. We price the repair and the rebuild so the choice stays yours.
Large areas that have separated from the lath, a failed moisture barrier, or rot found in the wall behind. New stucco over a compromised wall only moves the failure date, so where a wall is genuinely finished we will say so and talk you through the cladding options as well.
A good repair blends. It very rarely disappears. Anyone who promises you an invisible patch on a weathered wall is telling you what you want to hear. Texture itself can be matched closely, because a knockdown, a sand float, a dash or a hand-troweled pattern can all be reproduced by hand on site by someone who has done it before. Colour is the harder half. Your existing wall has spent years in Calgary sun and weather, and fresh stucco starts life at its original shade, so even a perfect texture match will read slightly newer for a while. In the right light, on the right elevation, that difference is easy to miss. On a large south-facing wall with heavy fading, it will show.
We read the pattern on your wall before we start and work the finish coat to it, then feather the repair well past its own edge so there is no hard line where the new material stops.
Weathered stucco and new stucco do not start at the same shade. A patch on a sheltered or shaded elevation usually settles in quietly. A patch on a faded, sun-hammered wall will be visible until the whole elevation is evened out.
The only way a repair truly disappears is a finish applied across the whole elevation once the stucco has cured, so the entire wall carries the same tone. That is a separate decision and worth costing on its own merits.
Fresh stucco needs proper cure time before any finish goes over it, so evening out an elevation is normally a later step rather than the same visit. When that is the route you want, it is handled through our exterior painting and coatings work, and the rest of the envelope sits under our exteriors services.
Stucco repair goes well when the diagnosis comes before the trowel. Here is exactly what to expect.
We walk each elevation, map where the cracking actually is, and sound the wall by hand to find any area that has let go behind the surface.
We trace roof edges, flashings, window details and downspout discharge, because a repair holds only if the water stops arriving.
Failed material comes off until we reach stucco that is solid, and the lath and moisture barrier underneath get checked before anything goes back on.
The section is rebuilt in coats, then the finish is worked by hand to the texture already on your wall and feathered out past the repair.
Fresh stucco needs time before anything is applied over it. We walk the finished elevations with you and set realistic expectations on colour.
Usually, yes, and it is the part of the job that decides whether the repair disappears or announces itself. Stucco finishes vary a lot - sand float, dash, knockdown, worm and smooth trowel all behave differently - so the patch has to be worked with the same technique and the same aggregate size as the original wall. We match the texture on site rather than applying a standard finish and hoping it blends. An older wall that has weathered for years is harder to match perfectly than a recent one, and we will tell you honestly when a patch is likely to stay slightly visible until the wall is recoated.
Texture matches better than colour does. Even a correctly tinted patch tends to read slightly different from stucco that has had years of sun, rain and dust on it, because the surrounding wall has faded and the new material has not. On a wall with integral colour the patch can be tinted close, but the honest expectation is close rather than invisible. Where an exact match matters to you, the usual answer is to repair first and then recoat the elevation so the whole wall reads as one surface. That coating work is covered on our exterior painting page.
It depends on the temperature and the product, not the month. Cement-based stucco needs warmth to cure properly, and the threshold is higher than most people assume - product data sheets typically call for the wall and the air to stay above roughly five degrees for a sustained curing period, not merely above freezing for an afternoon. That is why a brief chinook is not automatically a working window, and why patching in the cold produces a repair that fails later. If your wall is actively letting water in and the weather will not allow a proper permanent repair, the sensible move is a temporary measure to keep water out, then the real repair when conditions allow. We will tell you which situation you are in rather than doing permanent work in conditions that will not hold.
It can, if only the crack was filled and not the reason it cracked. That is why we look at what is moving before we patch. A hairline crack from normal shrinkage or a chinook swing usually stays fixed once it is properly opened, filled and textured. A crack that traces back to foundation movement on clay soil, a failed flashing detail, or water getting behind the wall will reopen no matter how good the patch is, because the wall is still moving or still getting wet. In those cases the cause has to be addressed first, and sometimes that is work outside stucco entirely.
Fine crazing across a wall is common and often cosmetic, and not every hairline needs immediate attention. What changes the answer is water. A crack that is wide enough to take in moisture becomes a freeze-thaw problem here, because water that gets in and then freezes expands and works the crack wider every cycle. That is how a cosmetic line becomes a spalled section over a few winters. As a rough field rule, fine crazing can often wait and a crack wide enough to catch a fingernail is worth looking at sooner, but width alone does not decide it. What the crack is doing matters more: one that is lengthening, one that runs diagonally from a window or door corner, one that sounds hollow around it, or one with staining below it should be looked at now regardless of how wide it is.
You can, and for a very fine hairline in a low-visibility spot it may hold for a while. The two things that go wrong are that flexible caulk does not take texture, so the repair reads as a smooth line across a textured wall and stays visible, and that sealing the face of a crack can trap moisture behind the stucco rather than keeping it out. On a structural crack it also hides the movement you would want to be watching. If it is a small cosmetic line and appearance does not matter to you, a DIY patch is a reasonable stopgap. If the crack is wide, growing, sounds hollow nearby, or shows staining, it is worth having looked at.
Repair is usually the right call when the damage is localised - individual cracks, a spalled patch, a section around a window - and the wall underneath is sound. Replacement enters the conversation when large areas sound hollow because the stucco has debonded from the substrate, when there is widespread spalling across multiple elevations, or when moisture has got in long enough to damage what is behind the stucco, in which case the sheathing has to be dealt with regardless of the finish you put back. Some homeowners also take the opportunity to change the look of the house. If replacement is the honest answer we will say so, and fibre-cement siding is the usual alternative here.
Sometimes, and it depends on the cause. Sudden damage from a specific event, hail being the obvious one in Calgary, is more likely to be covered than cracking that developed gradually, because most policies treat wear, settlement and long-term deterioration differently from sudden accidental damage. Coverage, deductible and how the adjuster reads the damage all vary by policy. We photograph and document what we find so you have something concrete to bring to a claim, but confirm the specifics with your insurer, since we cannot speak to what your individual policy covers.
Tell us what the wall is doing. You’ll get a clear written quote.
Serving: Calgary, Airdrie, Cochrane, Okotoks, Chestermere. Flexible financing available.