Usually Normal: Minor Settling
- Thin, hairline vertical cracks in a poured basement wall that stay the same width
- Small shrinkage cracks in a basement floor or garage slab
- A few hairline drywall cracks in a newer house during its first years
These are common as concrete cures and a house adjusts to its site. They are still worth watching, and a crack that lets water in should be sealed.
Signs of Foundation Problems to Have Inspected
- A horizontal crack in a basement wall, or a wall that bows or leans inward
- Stair-step cracks in block walls or exterior brick
- Cracks that grow longer or wider over weeks or months
- Cracks where one side sits higher than the other, or that are wider at one end
- Doors and windows that suddenly stick, swing on their own or no longer latch
- Floors that slope toward one side of the house
- Gaps between walls and ceilings, around trim, or between the chimney and the house
- Water coming through a wall crack every time it rains
Types of Foundation Cracks and What They Mean
The direction and shape of a crack usually say more than its length. Use this as a first read, not a diagnosis: only an inspection on site can tell you what is really happening.
Hairline Cracks in a Foundation
Very thin cracks, about the thickness of a credit card or less, in a poured wall or slab. Most come from concrete shrinking as it cured and are common in houses of every age. Mark the ends and watch them. Seal one if water comes through it.
Vertical Cracks in a Foundation
Straight up and down, or nearly, often starting at a corner of a basement window or running from the top of the wall. In poured concrete they are usually shrinkage cracks and rarely structural, but they are a frequent source of leaks. Worry more if one gets wider, if it is wider at the top or bottom, or if water keeps coming through it.
Diagonal Cracks in a Foundation
Running at an angle, often from a corner or from the edge of a window or door opening. They usually point to uneven settling: one part of the foundation has moved down more than the part next to it. Check upstairs for matching cracks above doors and for doors that stick.
Stair-Step Cracks in a Foundation
Cracks that zigzag along the mortar joints of a block wall or exterior brick. They come from settling or from soil pushing on the wall. A few hairline stair-step cracks can be old and stable. Wide ones, blocks that have shifted out of line, or a pattern that keeps growing need an inspection.
Horizontal Cracks in a Foundation
A crack running along the length of a basement wall, often partway up, sometimes with the wall leaning or bowing inward. This is the pattern to take most seriously: it usually means soil and water pressure, or frost, are pushing the wall in. In Fort Wayne, wet clay against block walls is a common cause. Have it looked at soon, and see how bowing walls are braced.
Cracks in a Slab Foundation: When to Worry
Thin cracks in a concrete slab are common and usually come from shrinkage. Worry more when a slab crack is wide enough to catch a coin, when one side is higher than the other, when it keeps widening, or when it lines up with cracks in the walls and sticking doors above. Those point to soil movement under the slab rather than normal shrinkage.
Foundation Settling Versus Active Movement
A house that settled years ago and stopped may only need cosmetic repair. A house that is still moving needs the cause fixed. Around Fort Wayne, clay soil that swells when wet and shrinks when dry can make cracks open and close with the seasons, so one look is not always enough. Tracking a crack for a few months answers the question better than any single visit.
How to Track a Foundation Crack
- Number each crack with a pencil or marker and note where it is (wall, corner, distance from a window).
- Mark both ends with a short line and the date. If the crack grows, the new length shows past your mark.
- Measure the width at one marked spot each time: a ruler with fine marks, or a printed crack width card, works.
- Take a photo from the same spot each time, with a ruler or coin in the frame for scale.
- Note what you see around it: water, a wall that leans, doors upstairs that stick.
- Check again every few weeks, and always after a wet spring and a dry late summer.
Crack monitors. A crack monitor (or crack gauge) is a small two-part plastic plate with a grid. You fix one half on each side of the crack, and any movement shows as the two halves slide against each other. They are sold at hardware stores and online, and are the most precise way for a homeowner to see whether a crack is moving.
Free printable crack log. Download the foundation crack log (PDF): one page with room for six cracks and twelve check dates, plus the steps above. Bring it to the inspection: a contractor or engineer can see at a glance what is changing.
What to Do Next
- Fix easy water problems now: clean gutters, extend downspouts and slope soil away from the house.
- Do not patch over a crack you want inspected. The pattern is evidence.
- For a wall that is bowing or a house that is clearly moving, get an inspection soon. Repairs usually grow with the damage.
Learn about foundation crack and wall repair, piers and house leveling and basement waterproofing in Fort Wayne.