Foundation crack types in Michigan and what each pattern usually means

A crack is a symptom, and the pattern is the clue

A seller of crack repair has a reason to call every crack structural. Someone selling nothing has a reason to call every crack cosmetic. Neither is a reading of your wall. University of Minnesota Extension, an out-of-state land-grant source we use because we could not read any Michigan extension page on the subject, says concrete and block foundations usually develop some cracks, that soil settling causes cracking, and that repair may be necessary. That is the honest baseline: cracks are common, some matter, and the job is to sort which.

Sorting starts with four observations you can make with a flashlight, a phone and a pencil. Note the direction the crack runs, where it sits on the wall, whether it seeps after rain, and whether it has changed since you first saw it. Write the answers down before you call anyone, because the order of that conversation matters and we come back to it below.

Vertical cracks

A crack that runs roughly straight up and down, often near the middle of a poured wall or near a corner, is the pattern most often tied to the concrete itself settling and curing. It is also the pattern most often found with water, because a straight crack goes all the way through the wall. Dry and unchanged over several months, it is usually a candidate for watching. Wet, it is a drainage question first. University of Minnesota Extension puts the order of work plainly: control interior moisture, then fix grading, gutters and downspouts, which it says may solve the problem, and only then consider a drainage system. Our wet basement fix order guide walks through it.

Stair-step cracks in block and brick

In a block wall, cracks tend to follow the mortar joints, stepping up or down in a diagonal. They suggest that one part of the wall has moved relative to another, which is what uneven support under a footing does. A single stair-step that has not changed is one thing. A stair-step that widens, or that has a matching crack on the other side of the house, is a pattern to show a professional engineer. The pattern points at settlement, and settlement is a diagnosis about soil and footings that nobody can make from a photograph.

Horizontal cracks

A horizontal crack, often at about the height of the soil outside, is the pattern to take most seriously. It usually means soil is pushing the wall inward, and the wall may be leaning or bowing along that line. Look along the wall with a flashlight held flat against it, and compare the wall with a straight edge.

This is where the building code gives you something concrete. The 2015 International Residential Code, which is the base of the Michigan Residential Code now in force, says concrete or masonry foundation walls must be designed by accepted engineering practice where they are subject to hydrostatic pressure from ground water, or where they support more than 48 inches of unbalanced backfill without lateral support at the top and bottom. A wall bowing under water or soil pressure has, by definition, met a condition the standard wall tables were not written for. That is our inference, and it is the reason a horizontal crack with a lean sends us to an engineer, not a crew. See bowing basement walls for the repair side.

Floor cracks and sloping floors

Cracks in a basement slab are very common and often only shrinkage. A crack with one side higher than the other, a floor that slopes toward one wall, or a gap opening between the slab and the wall belongs with the settlement patterns above. Doors and windows that suddenly stick, or trim that has pulled away from a wall, are the same kind of evidence from inside the house. Note them in the log. A slab that has dropped is a different job from a wall that is moving, and slab leveling covers the flatwork side.

Where the joists meet the wall

University of Minnesota Extension notes that cracks can be severe if floor joists are not connected to the wall. Under the 2015 code, wood sill plates on a continuous foundation are anchored with bolts at set spacing, and Extension says the joist-to-sill and wall connection keeps walls from moving. You cannot judge an anchor from the basement floor, but you can look at the top of the wall from inside and see whether the sill plate sits on the concrete and whether there are bolts. Tell the engineer what you saw.

A measurement log that settles arguments

A crack that grows is evidence. A crack that does not grow, over a season that includes a Michigan thaw and a wet spring, is also evidence, and it is free.

• Photograph the crack with a coin or ruler beside it for scale, from the same spot, each time.
• Mark the ends with a pencil and write the date next to each mark.
• Note the weather and whether the wall was wet that day.
• Repeat every few weeks, and after any heavy rain or snow melt.

Keep every photo with its date. If you later sell, the Michigan Seller Disclosure form asks about evidence of water in the basement and about settling, flooding, drainage, structural or grading problems, and a dated record answers those questions honestly.

When the pattern points to an engineer

Take the crack to a professional engineer before you take it to a repair company when it is horizontal, when the wall leans or bows, when a stair-step keeps widening, when doors and floors are changing together, or when two contractors tell you opposite things. The reasoning is the thesis of this site: the company that diagnoses a problem often sells the fix, so a read from someone with nothing to sell comes first. Our guide to getting an engineer first covers how, and the crack identifier tool turns the observations above into a next step.

We are a referral service, and foundation companies pay us. That is why we say this plainly.

Who may do the repair, and whether it needs a permit

Michigan has no foundation license category. Crack injection, sealing and wall repair on a home count as repair or improvement of a residential structure, so a contractor charging $600 or more for labor and materials, aggregated and not split into smaller jobs to avoid the limit, needs a LARA residential builder license or a maintenance and alteration license. The M&A crafts include concrete and masonry, and which craft matches a given crack job is our reading of MCL 339.2404. A homeowner repairing their own occupied home needs no license. Check any contractor on the LARA license search, and see how to check a builder license.

On permits, we found no state or city page naming crack sealing or injection. The base code requires a permit to construct, alter or repair a structure, and it lets ordinary repairs skip notice but not cutting away of walls or structural supports. Crack injection is not named, so the answer comes from your city’s building office. Ask before the work, and ask whether the contractor will pull the permit if one applies.

What happens next

If your pattern is a dry vertical crack that has not moved, log it and revisit in a season. If it leaks, start with the outside of the house. If it is horizontal, stair-stepping and widening, or paired with sticking doors, get an engineer’s read. When you are ready for a contractor, foundation crack repair explains what the work involves and what to ask for in writing.