Which kind of foundation crack is this, and what should you do first?

Chosen when: Is anything else happening: A wall bows or leans, a floor slopes, or doors and windows stick

A bowing or leaning wall, a sloping floor or doors that have started to stick together point to movement, and a crack in that case is a symptom, not the problem. Michigan's base code says concrete and masonry walls under groundwater pressure, or holding back more than 48 inches of unbalanced backfill, need engineered design, so an engineer is the right first call and a repair company the second. The state does not require a stamp for ordinary repair, which is why you have to ask for the report yourself.

Try first: Photograph the wall with a level or string line, date the photos, and book a licensed professional engineer who does not sell repairs.

Stop and call someone if: The floor above sags, a wall visibly shifts, or you feel unsafe: leave the area and call 911.

Bowing walls · Get an engineer's read before you hire a Michigan foundation contractor

Chosen when: Which way does the crack run: Horizontal

A horizontal crack in a basement wall usually means soil or water is pushing on the wall from outside, and walls designed to hold back soil are exactly where the code asks for engineering. That is a general explanation, not a diagnosis of your wall. The dated marks and an engineer's read will show you which: old and finished, or still moving.

Try first: Mark both ends with pencil and the date, photograph it, and look outside at grade, gutters and downspouts on that side.

Stop and call someone if: The crack lengthens, the wall bulges, or water follows it.

Bowing walls · Get an engineer's read before you hire a Michigan foundation contractor

Chosen when: Has it changed: Longer, wider or the sides no longer line up

Growth is the most useful thing the log can tell you, because it separates a settled crack from an active one. University of Minnesota Extension, an out-of-state land-grant source, says soil settling causes cracking and that cracks can be severe if joists are not connected to the wall. A contractor can seal a growing crack, but the seal will not tell you why it moved.

Try first: Write the date and size of the change next to your first mark, then ask an engineer or a second company for a written opinion before you sign anything.

Stop and call someone if: Water starts to come through, doors stick, or a second crack appears.

Foundation cracks · Foundation crack types in Michigan and what each pattern usually means

Chosen when: Is anything else happening: Water or damp along the crack

Water along a crack is a drainage question before it is a structural one. University of Minnesota Extension says to control interior moisture, then correct grading, gutters and downspouts, and only then consider an interior or exterior drainage system, and that many summer leaks are condensation. In Michigan, the State Police say floods often follow snowmelt and heavy spring rain, so watch the wall then.

Try first: Extend downspouts, check that grade slopes away from the wall, and note when the water appears: after rain, after thaw, or always.

Stop and call someone if: Water reaches the electrical panel or outlets, or a pump that keeps running cannot keep up.

Basement waterproofing · How to waterproof a basement without digging, and what that can and cannot fix

Chosen when: Which way does the crack run: Stair-step in block or brick

A crack that follows the mortar joints in steps is a pattern associated with one part of a wall moving relative to another, often because the soil under it has shifted. That is a general reading, not a diagnosis. A step crack alone cannot show how old it is, so the dated log matters, and so does knowing if the movement has stopped.

Try first: Mark each end with a date, photograph it, and check whether doors or windows near it have started to stick.

Stop and call someone if: The steps lengthen or the wall surface moves out of line.

Foundation cracks · Foundation crack types in Michigan and what each pattern usually means

Chosen when: Which way does the crack run: Diagonal

Diagonal cracks often start at the corners of windows and doors, where a wall is weakest, and may be old shrinkage or settlement. Which one is a question for a person standing in your basement. Cracks of every kind are common in foundations, as University of Minnesota Extension says, and what matters is whether the crack moves.

Try first: Date-mark both ends and photograph. Recheck monthly and after a thaw or a big rain.

Stop and call someone if: The crack grows, the wall moves, or water comes through.

Foundation cracks · Foundation crack types in Michigan and what each pattern usually means

Chosen when: Which way does the crack run: Mostly vertical; Has it changed: Same as my dated marks or photos

A vertical crack that has not changed across your dated marks is often a finished event, and monitoring is a reasonable plan while you attend to drainage. Sealing it may stop water, but ask the person sealing it what caused it and what they would do if it moved again. A crack repair of $600 or more by a contractor needs a LARA builder or maintenance and alteration license, with concrete or masonry the likely craft, which is our reading.

Try first: Keep the log going for a full freeze and thaw cycle, and keep gutters and downspouts clear.

Stop and call someone if: The crack widens, lengthens or leaks.

Foundation cracks · Foundation crack types in Michigan and what each pattern usually means

Chosen when: Any other answers

With no dated marks there is no way to tell whether a crack is moving, and a contractor can only guess. Put a pencil mark and the date at each end of the crack, photograph it with a ruler or coin for scale, and look again in a month. Michigan's freeze and thaw cycle moves the ground, so check again after the spring thaw too.

Try first: Mark, date and photograph the crack today, then look at it monthly.

Stop and call someone if: Water, a bowing wall, a sloping floor or sticking doors appear.

Foundation cracks · Foundation crack types in Michigan and what each pattern usually means