Foundation Wall Cracks, Part 1: When It Looks Bad but Isn’t a Big Deal
Have you ever stepped into your basement and noticed cracks in the foundation walls? Maybe they’re inside, maybe on the exterior just above the soil line. Some homeowners see cracks that never change, others notice a small one that grows over time — and some have never looked closely until now.
The truth is, many basements develop cracks at some point in a home’s life. Sometimes it happens after decades, sometimes before construction is even finished. So… why are those cracks there, and should you be worried?
The short answer: not always.
There are several possible causes, and some are harmless while others point to real structural issues. This three-part series breaks them down clearly:
Part 1: Cracks that look bad but aren’t a big deal.
Part 2: Cracks that might need attention but are relatively uncommon.
Part 3: Cracks that often signal active movement — and what to do about them.
Cracks in Surface Coating (Parge Cracks)
Concrete block foundation walls often have a surface coating, called parging, to smooth the wall and add mild weather resistance. This coating bonds differently to the blocks and the mortar joints, and small cracks often form along those joints.
In this case, the cracks are usually only in the coating — not in the structure itself. That means you’re looking at a cosmetic issue, not a structural one. It might not look pretty, but your wall’s strength isn’t compromised.
Tremor or Earthquake-Related Cracks
Here in Virginia, earthquakes aren’t common — but small tremors do happen. After a couple stronger ones in the past decade (especially near the Palmyra area), I inspected numerous homes where vertical, jagged cracks had appeared in foundation walls.
In nearly every case, the cracks had been there since the tremor and hadn’t changed a bit. These stress cracks are typically sporadic and not full-height. If there’s no sign of movement or water intrusion, they’re almost always harmless. My advice: monitor, don’t panic.
Cracks from Construction Stress
Sometimes a home develops random cracks soon after being built — especially in block foundations. When I inspect a newer home (and “new” to me can still mean 20–30 years old), I always ask, “When did you first notice the cracking?”
If the answer is “Right when we moved in,” that’s actually good news. Heavy construction equipment or improper backfill compaction can cause stress during or right after the build. Unless the wall shows measurable movement, these cracks are usually one-time events that don’t progress.
Builders typically warranty structural components for five years, so if the home is still under warranty, it’s worth having them patch it. I’ve only seen one severe case — an excavator bumped the foundation hard enough to cause inward movement. That’s the rare exception.
Concrete Shrinkage Cracks in Poured Walls
If your foundation is poured concrete (not block), you may see one or more narrow vertical cracks. These can form as the concrete cures and shrinks — a completely normal process.
A few of these cracks? Totally common. Dozens of them? Sounds like the builder biffed it.
When I inspect such cracks, I check for movement and water entry. If the wall hasn’t shifted, you’re simply dealing with shrinkage, not failure. The main risk here is water infiltration. Solutions include:
Epoxy injection (seals the crack with an epoxy resin)
Flexible interior membrane systems (such as those used by Basement Systems®)
These are inexpensive fixes compared to repairing a failing foundation.
Key Takeaway
Not every crack means trouble. Surface coatings, tremor-related lines, minor construction stress, and concrete shrinkage are often harmless. Still, keeping an eye on them and getting an unbiased inspection ensures small issues don’t become big ones.
If you’re in Central Virginia and aren’t sure what your cracks mean, schedule an inspection with Integrity Foundation Inspections. I’ll tell you honestly whether it’s cosmetic or cause for concern — no sales pitch, just straight answers.
Schedule an Inspection →
Coming Next: Cracks That Might Need Attention
In Part 2, we’ll look at cracks that don’t necessarily spell disaster but do deserve a closer look — from vertical bulging to horizontal seams that hint at something abnormal.
