Is my house settling normally, or is it a foundation problem?

What "settling" really means

People use "settling" for any movement. Engineers split it into three kinds, and the difference matters for the fix. The Foundation Performance Association (FPA), a Houston group of engineers, defines them this way^[2]:

Type	What happens	Where it is common
Settlement	Soil compresses under the weight of the house, including slow long-term squeezing of water out of clay	Can happen in any soil[2]
Subsidence	Clay dries and shrinks, often from tree roots or drought, and that part of the house drops	Clay soils[2]
Heave	Dry clay takes on water, swells, and pushes that part of the house up	Clay with high swell potential and a water source[2]

So "my house is settling" might really be a house that is rising in one corner. That changes the repair. See heave vs settlement.

Some movement is built in

All foundations on soil move to some degree, says a National Association of Home Builders (NAHB) guidance paper written by a licensed engineer^[1]. Foundations are designed for it. Most are designed for up to 1 inch of soil movement, and slabs in highly expansive soil areas for up to about 4 inches^[1].

Where you live sets the odds. By our calculation from USDA soil survey data, about 70% of rated soil area in Dallas County, Texas is high or very high for shrink-swell, versus about 37% in Cook County, Illinois and about 1% in Franklin County, Ohio^[5]. In Ohio and Illinois, frost is the other driver: see frost heave.

Normal signs in a new or newer home

NAHB says concrete, mortar, grout and stucco can shrink and crack for months after construction as they dry, and wood framing and trim shrink as they adjust to indoor humidity^[1]. FPA lists these common items as usually not foundation movement^[3]:

• Nail pops in walls and ceilings: wood shrinkage. Wait about two years, then repair^[3].
• Crown molding gaps and drywall tape separations in new homes: wood shrinkage. Wait about two years, then repair^[3].
• Hairline cracks in tile or grout in new homes: the slab kept shrinking after the tile went down. Wait until the cracking looks dormant, typically 1 to 2 years, then replace^[3].
• Random hairline cracks in the slab with no distress above: shrinkage during curing. Wait until dormant, then repair as needed^[3].

NAHB adds that builders prefer to make cosmetic repairs near the end of the typical one-year workmanship warranty, after the soil has adjusted^[1].

Signs that are not just settling

Cracks alone are not proof of a structural problem. NAHB says they become more likely to be one when they come with other distress, such as doors and windows that stop working or floors that slope too much^[1]. Watch for:

• Cracks with one side higher than the other. NAHB says significant vertical displacement may indicate a structural concern^[1].
• Cracks that keep growing after the first year or two.
• Doors that stick, will not latch, or swing on their own, especially several at once^[2].
• Floors that slope enough to notice. FPA says slopes of 1% or more, about 1/8 inch per foot, may be noticeable^[2].
• Gaps between brick and window or door frames and cracks that run through brick veneer^[2].

One caution: a door that binds at the bottom but opens easily when lifted by the knob usually has a loose or undersized hinge, not a foundation problem^[3].

Older homes: harder to tell

FPA notes that older houses typically show more distress than newer ones, and that the cause gets harder to pin down with age because of past repairs and incomplete history^[2]. A floor can be out of level simply because it was built that way. FPA found most residential slabs are built within 1 inch of level^[2], so one survey without a baseline cannot prove the slab moved. FPA recommends that buyers get a baseline elevation survey for later comparison^[2].

How to track it yourself

You can gather useful evidence before anyone visits:

1. Mark each crack. Pencil a line across both ends and write the date beside it.
2. Measure the width with a crack gauge or a ruler with fine marks, and photograph it next to a coin or ruler.
3. Recheck every season. A crack that is the same in a wet spring and a dry August is likely dormant.
4. Note doors and windows that change from easy to hard to close.
5. Fix water first. FPA says repairs on clay depend on keeping soil moisture steady and sending storm water away from the foundation^[4]. Downspouts that dump at the foundation and leaking pipes are common triggers.

Our crack assessment checklist walks through these steps, and the crack width guide explains what widths mean.

When to call a pro

• Cracks that keep widening, or with one side higher than the other.
• Several doors or windows that begin to stick at the same time, or floors you can feel slope.
• Movement after a plumbing leak, a big tree removal or a long drought.
• Before buying or selling a house with visible cracks: a licensed structural engineer's elevation survey gives you a baseline and a diagnosis.