Why Does Concrete Crack — and How We Prevent It in Portland

One of the most common questions we hear is: "Will my concrete crack?" The honest answer is that all concrete can develop hairline cracks — but proper installation controls where cracks go and keeps them from becoming a problem. Here's what causes cracking and how we prevent it.

Shrinkage as Concrete Cures

Concrete shrinks slightly as it cures and dries. Without a plan, that shrinkage shows up as random cracks. The solution is control joints — grooves cut or tooled into the slab at engineered spacing that give the concrete a planned place to crack, hidden along clean lines.

A Poor Base

This is the number one cause of serious cracking in the Portland area. Our clay soils hold water and move with the seasons. A slab poured on thin or poorly compacted fill will settle and crack. We excavate and compact a proper crushed-rock base on every pour.

Drainage and Water

Standing water and poor drainage undermine a slab over time, especially through our wet winters and freeze-thaw cycles. We grade every project to shed water away from the slab and your home.

Not Enough Reinforcement or Thickness

Driveways and slabs that carry vehicle loads need adequate thickness and steel — rebar or wire mesh — to hold together and distribute load. We size both to the job.

Curing Too Fast

Concrete that dries too quickly is weaker and more crack-prone. Proper curing after the pour matters, and our crews manage it.

The Bottom Line

You can't guarantee concrete will never get a hairline crack, but with a compacted base, good drainage, proper reinforcement, correct thickness, control joints, and careful curing, you can control it — and that's exactly how we build. Contact Oregon Concrete Company to learn more.