Problems
Common concrete problems
Something is wrong with your concrete and you do not know what to call it.
Almost every residential concrete problem is one of three things: the concrete has moved, the surface has deteriorated, or the concrete has cracked. Those three have different causes, different fixes and very different costs, and telling them apart is most of the work of deciding what to do.
This page is a map. Find what you are looking at, then follow it through to the detail.
It has moved
Something sits lower than it used to, or lower than the concrete next to it. There may be a step at a joint, a gap where the slab has pulled away from a wall or step, or water now sitting where it never used to.
Movement is a ground problem showing up in the concrete. The concrete itself is often perfectly sound. This is the family of problems where lifting is a genuine alternative to replacement.
- Sunken concrete — one or more sections sitting lower than they should.
- Concrete settlement — the underlying process, and why it happens.
- Uneven concrete — surfaces that no longer sit flat or flush.
- Voids under concrete — space beneath a slab, often before it drops.
- Trip hazards — the specific, common case of a step at a joint.
The surface has deteriorated
The concrete is where it should be, but the top of it is coming apart: flaking away in thin layers, pitting, or breaking off in chunks with aggregate showing through.
Surface deterioration is usually about water, freezing, salt, or how the concrete was finished and cured in the first place. It is the family where sealing, resurfacing and coatings are relevant — provided the slab underneath is sound.
- Spalling concrete — surface breaking away, often exposing aggregate.
- Flaking and scaling — thin layers lifting off the surface.
It has cracked
Cracks are the most common concern and the most frequently over-interpreted. Concrete cracks. Nearly all of it does, and most of those cracks are consequences of shrinkage and temperature rather than signs of anything failing.
What makes a crack worth attention is not its existence but its behaviour: whether one side has dropped relative to the other, whether it is still growing, and whether water is getting into it.
- Cracked concrete — how to read a crack rather than just find one.
- Poor drainage — the cause behind a large share of everything above.
Why drainage keeps appearing
Water is the common thread through most of these problems. It moves soil, which causes settlement. It gets into concrete and freezes, which causes surface damage. It collects in cracks and widens them.
This is why a contractor who looks at your downspouts and grading before quoting is usually the one taking the job seriously. Fixing concrete without fixing why it failed produces a repair with a countdown on it.
Common questions
How do I tell the difference between a serious problem and normal wear?
The most reliable single indicator is whether anything is still changing. Concrete that cracked a decade ago and has not moved since is doing what concrete does. Concrete that has changed noticeably in the last year is telling you something is ongoing. A pencil mark across a crack and a photograph with a date will tell you more than most inspections.
Do I need an engineer or a concrete contractor?
For residential flatwork — driveways, patios, walkways, garage floors — a concrete contractor is usually the right first call. Where a problem involves the house structure itself, such as foundation walls or footings, that is a different assessment and a different professional. If a contractor suggests the problem is structural, take that seriously rather than shopping until somebody says otherwise.
Work it out, or judge the quote
Freeze–thaw and soil risk guide
How water, freezing, soil movement and compaction damage slabs — and how to tell which one you have.
Open it →Repair or replace tool
Ten questions about what you can see, and the options your answers rule out.
Open it →Crack severity assessment
Read what a crack is doing rather than guessing from how wide it is.
Open it →Related guides
Sunken concrete
A slab that now sits lower than it should — almost always a ground problem, not a concrete problem.
Read more →Cracked concrete
Most concrete cracks. Reading what a crack is doing matters far more than finding one.
Read more →Spalling concrete
Surface breaking away in chunks, often with aggregate showing — usually water, freezing and salt.
Read more →Poor drainage around concrete
Where water goes decides how long concrete lasts — and it is the most commonly skipped part of a quote.
Read more →Repair or replace?
The central question: when repair holds, when it is money spent twice, and how to tell.
Read more →