Why Drywall Cracks in Mountain Homes, and Which Cracks Matter
Showcase Drywall · Eagle, Colorado · 26 years in the valley
Most drywall cracking in a Vail Valley house is cosmetic. It comes from the house moving with the seasons, from the dry air at this altitude, or from a taped joint that was never going to hold. A few are a sign of something structural, and the signs are readable if you know them. Knowing which is which decides whether you have a surface problem or a structural one, and the shape and location of the cracks usually tell you.
This article covers the common causes, how to read what a crack is telling you, and how crack repairs are done so they do not come back in the same place next spring.
The short answer
A house is not a rigid object. Framing lumber shrinks as it dries, the roof structure lifts and settles with the temperature in the attic, the ground under the foundation moves with moisture and frost, and the whole assembly expands and contracts through the year. Drywall is a brittle sheet fastened across all of that movement, and it relieves stress by cracking at its weakest points, which is why the cracks land where they do: the joints between sheets and the corners around openings.
So the common cracks are not a structural failure. They are a material doing what it does. The question worth asking is whether the movement behind the cracks is normal seasonal movement or foundation problems, and that is what the pattern tells you.
Causes of drywall cracks, in order of how often we see them
Seasonal movement and dry air
This is the biggest cause in these homes. Framing arrives with moisture in it and dries out over the first year or two, shrinking as it goes. After that, the air in a mountain house swings from humid in a wet summer to extremely dry in winter with the heat running. Wood takes up and gives off moisture with those swings, so the whole frame of the house changes dimension slightly through the year.
Drywall cannot follow that movement, so it cracks where the panels meet. Cracks on walls and ceilings typically open in winter and close partially in summer, which is why cracks you filled in January can look fine in July and reappear the following January.
Truss uplift in the attic
A specific and very common cause of cracks in ceilings in snow country, and the one most often misread as a structural problem. The bottom chord of a roof truss sits in the insulated attic floor, warm and dry. The upper chords sit in the cold attic space above the insulation, in attic air that is nothing like the air below. In winter the difference in moisture between them makes the truss arch slightly upwards, lifting the middle of the ceiling with it and leaving cracks where the ceiling meets the interior walls. That is physics rather than a defect.
Truss uplift has a signature: it runs along the top of an interior partition wall, it appears in winter, and it closes up in summer. That is just movement, not damage. It is also best fixed by letting the ceiling move rather than by fastening it harder.
Settlement
New houses settle. The soil compresses under the weight of the structure, and the movement is largest in the first couple of years. Settlement cracks usually show at the corners of doors and windows in walls, running diagonally away from the opening, because an opening is where the wall is weakest.
Settlement spread evenly across a house is normal. Uneven settlement, where part of the house moves and the rest does not, is what keeps producing cracks after the first few years.
Poor taping
Some cracks are workmanship. If a joint was taped with too little compound under the tape, the tape does not bond and eventually releases, showing as long straight cracks along the joint line, sometimes with the tape edge visible. The same happens when compound is applied too thick in one coat and dries with internal stress in it.
Workmanship cracks read differently from movement cracks: dead straight, following a panel edge precisely, often with a lifted edge you can feel with a fingernail.
Foundation movement
The least common and the most serious of these problems. Water is the mechanism: poor drainage against the foundation, a gutter discharging at the wall, frost heave, or soil that swells and shrinks with moisture. The foundation moves unevenly, the framing above it racks, and the walls and ceilings crack at their weakest points.
Foundation movement comes with other signs in the house, which is how you tell it apart from everything above. A single sign on its own means little; two or three together mean something.
Impact, vibration and fastener problems
Doors that slam into a stop, heavy traffic on a floor above, or fasteners that were overdriven into the paper face all produce local cracking. These are small, isolated and easy to repair.
Reading what the cracks are telling you
| What you see | Likely cause | What it needs |
|---|---|---|
| Hairline crack along a ceiling-to-wall line, appears in winter, closes in summer | Truss uplift in the attic | Cosmetic repair, with a detail that lets the joint move |
| Straight crack following a panel edge, tape lifting | Taping workmanship | Cut out, re-tape, refinish |
| Diagonal crack from the corner of a door or window | Settlement or seasonal movement | Cosmetic repair once movement has slowed |
| Several diagonal cracks in the same direction across one area | Uneven settlement | Have the cause looked at before repairing |
| Wider than about a quarter inch, or wider at the top than the bottom | Structural movement | Structural assessment first |
| Cracks with doors and windows sticking, or sloping floors | Foundation problems | Structural assessment first |
| Stair-step cracking in a masonry wall or the foundation itself | Foundation problem | Structural assessment first |
| Horizontal crack across a basement wall | Foundation pressure | Structural assessment first |
Three things take cracks out of the cosmetic category: width, direction and company. Cracks wider than a quarter of an inch, cracks wider at one end than the other, and cracks arriving alongside sticking doors, sloping floors or visible foundation cracks all point to something structural. Those get looked at by an engineer before anyone picks up a taping knife. Getting that sequence wrong is the most common mistake owners make.
Everything else is a surface problem, and there are far more surface problems in these houses than foundation problems. Reading them wrong in either direction costs money: calling an engineer about seasonal movement wastes a fee, and repairing drywall over a live foundation problem wastes the repair.
Crawl spaces, basements and the moisture underneath
In a house built over a crawl space, what happens in that space shows up in the drywall above it.
A crawl space is a confined space in contact with the ground, and the air in that space is doing something all year. If the ground in the crawl space is damp and the space is not sealed, moisture evaporates into it and rises into the floor framing. The joists take up that moisture in summer and give it back in winter when the heat is running, and the floor above moves with them. Walls sitting on a moving floor crack at their corners and along their joints.
Frost makes it worse. Water in the soil beside a shallow foundation or under an unheated crawl space expands when it freezes, lifting whatever sits above that part of the foundation, and the structure moves a fraction of an inch, then drops again in spring. Drywall records the cycle as cracks that return each year in the same places.
The signs of trouble in a crawl space are worth knowing: a musty smell, visible damp or standing water in the crawl space, insulation hanging loose between the joists, floors that feel springy, and cracking concentrated above one area rather than spread through the house.
Repairing drywall above an unaddressed crawl space is money wasted. Seal the crawl space, deal with the drainage and the grading outside the foundation, then repair the walls. A good drywall crew tells you to do it in that order, even though the repair work is theirs.
Why mountain homes crack more than most
Four things make this valley harder on drywall than a mild climate would be.
The air is dry. That is just how winter works here. Winter indoor humidity in a heated mountain house can sit very low for months. Framing dries out, shrinks and moves more than it would in a humid climate.
The temperature range is wide. A house can see a 50 degree swing between a January night and a July afternoon, and the attic space sees more than that.
Snow load. A heavy roof load pushes down through the whole structure and then releases when it melts. The frame flexes, and brittle sheets attached to that frame record the movement.
Big openings and long spans. The architecture here favours tall glass, open stairwells, vaulted ceilings and long unbroken walls. Those are exactly the shapes with the least internal bracing, so they move the most, and the cracks show up at the corners of the openings.
None of that is a reason to expect a cracked house. It is a reason the drywall needs to be installed and finished with movement in mind, and a reason crack repairs that ignore the cause fail again.
Cracks in ceilings behave differently
Ceilings deserve their own paragraph, because cracks overhead worry people more than cracks in walls and usually mean less.
Most of the ceiling drywall in these homes is fastened to roof trusses, which are the parts of the structure that see the widest temperature and moisture swings. So the drywall cracks along the line where a ceiling meets a partition wall, and it does so seasonally. The same ceiling rarely cracks in the middle of a span, and when it does the cause is usually a taped joint that failed or a leak.
A ceiling is also harder to repair invisibly, because it is a single large plane with light crossing it at a shallow angle, so a repair that would vanish on a wall can look wrong overhead. That is why ceiling repairs are usually painted across the full plane rather than spot-painted, and why a ceiling costs more to repair than a wall of the same area.
How a drywall crack repair is done properly
Filling cracks with compound and painting over them is the repair that always comes back. There is still a joint under the filler, and the joint is still moving.
A repair that lasts works like this:
- 1. Open it up. Each one is cut out with a knife to make a clean V, and any loose tape or lifted compound is removed back to sound material. On a joint that failed, the old tape comes out.
- 2. Re-tape the joint. New tape, usually a mesh or paper tape set in compound, bridges the joint. This is what carries the movement instead of the paint film.
- 3. Coat and feather. Two or three coats of compound, each wider than the last, feathered well past the repair so there is no ridge.
- 4. Sand and match the finish. The surface is sanded flat, then the surrounding texture is matched and tested before it goes on the wall.
- 5. Paint the full surface. Wall corner to corner, or the whole ceiling. Spot-painted crack repairs show as stripes once the paint dries.
For truss uplift specifically, there is one extra option worth knowing about. Rather than fixing the ceiling rigidly to the partition wall, the joint can be detailed so the ceiling is free to move and the movement is hidden, usually with crown moulding fastened to the ceiling rather than to the wall. The cracks then have nowhere to appear. On ceilings that crack in the same line every winter, that is the fix that ends the cycle.
When to repair and when to wait
Timing matters with movement cracks, and getting it wrong means doing the repair twice.
On a new house, the first year or two produce the most movement as the framing dries and the structure settles. Repairing cracks in month three often means repairing them again in month fourteen. If the cracks are cosmetic, the usual advice is to let the house go through a full year, then repair everything at once.
On a house with seasonal cracks, repair in the season when they are at their widest, normally late winter. A joint re-taped when the gap is wide open will handle closing up far better than one taped when it is closed and then forced open.
On a house with cracks that are still growing, the cause gets addressed first. Repairing drywall over active structural movement is spending money on a surface that will crack again in the same place.
What this costs
Crack repairs are priced by the number of cracks, their length, the texture on the surface and how much painting is needed. A single crack in a smooth wall is just a small repair. A set of seasonal cracks through several rooms of a house, cut out, re-taped, matched and repainted, is a two to four day project and runs between about $1,200 and $2,500 in this valley.
The variable that moves the price most is the paint scope, since a lasting repair needs the whole surface painted rather than the repaired strip. The second is texture: matching a heavy hand texture around a long crack takes longer than matching a sprayed one.
Repair services for cracks, and what each one covers
Repair services divide into three kinds of work, and most houses need the first and nothing else.
Cosmetic crack repair. Cut out, re-tape, coat, match the texture, paint the surface. This is the service most seasonal cracking needs, and it is routine work.
Movement detailing. Used where the cracking keeps returning in the same line, typically a ceiling-to-wall joint moving with truss uplift in the attic. Rather than fighting the movement, the joint is detailed to hide it. These services cost slightly more once and stop the annual cycle.
Repair after the cause is fixed. Where a crawl space, a drainage problem or a foundation problem has been addressed by someone else, the drywall repair happens afterwards. Doing it in that order is the whole point, and doing it in the wrong order is why some houses get repaired twice. A crew that offers repair services without asking what is behind the cracking is not doing you a favour.
What you will notice about those three is that just one of the three is about the drywall. The other two are about the house. Cracking is a symptom, and a repair is worth more when somebody has worked out what went wrong behind it.
Questions about drywall cracks
Are cracks in drywall a sign of a bad build?
Rarely. Framing shrinkage and settlement in the first year or two produce cracks in most new houses, and in a dry climate at altitude they are close to universal. They are a finishing problem, not a defect in the structure, unless they come with the structural signs listed above.
Will the same cracks come back after repairs?
Not if the joint was re-taped rather than filled, and not if the underlying movement has slowed. Filled cracks with no new tape under them come back. So do repairs done over a problem nobody addressed.
Are cracks in ceilings worse than cracks in walls?
Not in themselves, but cracks overhead are more often truss uplift, which is seasonal and benign, and an overhead repair is harder to hide because it sits in one large plane under raking light.
Is cracking above a door a bad sign?
Usually not, and it is the most common sign owners ask about. The corners of openings are the weakest points in a wall, so ordinary movement just shows up there first. Worry if it is wide, growing, or the door has started to stick, because together they point somewhere else.
Can I just use caulk?
For cracks at the junction between ceilings and walls that move every winter, a flexible sealant is a legitimate repair and better than compound, because it stretches. For cracks in the middle of a wall or ceiling, no: caulk shrinks, holds paint differently and leaves a visible line.
Do your crack repair services include the painting?
They should, and our services do. Crack repairs without paint across the full surface are half a repair, and the half you can see.
Getting cracks fixed properly
If you have cracks appearing in the same places each winter, or a line overhead that opens up every January, the cause is usually straightforward and the repair services needed are routine. The thing to avoid is the cycle of filling and repainting the same cracks every year.
Showcase Drywall has been repairing cracks, matching textures and finishing drywall in Vail, Beaver Creek, Avon, Edwards, Eagle and Gypsum for 26 years. Call (970) 977-0247 for a free quote. If what we see looks structural rather than cosmetic, we will say so and tell you to get the cause looked at before we touch the wall.