Concrete Steps Cracked or Crumbling? Repair or Replace

Concrete stairs repair in Chicago comes down to one question: is the damage on the surface, or is the structure under it failing? Surface damage such as light scaling or a narrow crack can often be repaired. Steps that are sinking, broken through, loose, or showing rusted steel usually have to be replaced.

Here is how to tell which one you have, what repairs are possible, and what the City's permit rules say.

What kind of damage do your steps have?

Look at the steps in good light and match what you see to the list.

• Hairline or narrow cracks. Concrete guidance says most random early cracks rarely affect structural integrity or service life (NRMCA). They are common and often cosmetic.
• Flaking or crumbling surface. That is scaling, the flaking of the surface from freeze-thaw exposure, made worse by deicers (NRMCA).
• Small pits or cone-shaped holes. Those are popouts, caused when a near-surface aggregate particle freezes while saturated and fractures (NRMCA).
• A crack with one side lower than the other, or a step that has dropped. That is movement. See why your concrete stoop is sinking.
• Rust stains, or steel showing at an edge or corner. The reinforcement is exposed and corroding.
• A step that wobbles, sounds hollow or has broken away at the edge. The structure has lost its bond or its support.

Which problems can be repaired?

Narrow cracks. Concrete repair guidance lists epoxy injection under pressure as one potentially effective structural repair, with the cracks cleaned out first. The method varies by crack direction (American Concrete Institute). A contractor can tell you whether your crack is a candidate. We make no promise that any one repair holds, because that depends on why it cracked.

Scaled surfaces. The guidance is mixed, and worth knowing. Minor scaling is cosmetic and may not need repair. Light to moderate scaling can be resurfaced with a repair mortar after removing the unsound surface. A repair is only as strong as the base it bonds to, and it will not match the original color. Severe, progressing scaling may not be feasible to repair (NRMCA). For how that works on steps, see can you resurface concrete steps in Chicago.

Popouts. Small and mostly cosmetic. They can be patched.

Rust. Guidance says reinforcement should have at least 2 inches of cover to keep salt and moisture off the steel, so that rust expansion does not crack the concrete (NRMCA). When steel is already exposed and rusting at a step edge, the damaged concrete has to be opened up and addressed. Ask the contractor how long they expect that repair to hold.

When do steps have to be replaced?

Replacement is the honest answer when:

• The steps have sunk, tilted or pulled away from the house, and the cause is the base under them.
• The concrete is broken through, in several pieces or loose.
• The surface is scaled deeply and still getting worse.
• Rust has opened up the concrete across several areas.
• The step heights are uneven in a way that cannot be corrected by patching. Uneven rises are a trip hazard.
• The steps never had a proper base, and the problem is the base, not the surface.

A repair on top of a failing base is wasted money. If your steps are moving, read do concrete steps need footings in Chicago too.

Why do Chicago concrete steps crumble?

Salt and water. Scaling is the freeze-thaw damage deicers make worse, and the causes include non-air-entrained or low-air concrete, low-strength or permeable concrete, the wrong mix, and too much deicer, especially on new concrete (NRMCA). Guidance says to avoid deicers on new concrete in its first winter if possible and use clean sand instead. Afterward, use moderate amounts and rinse off salt tracked in on shoes and cars (NRMCA). Never use ammonium sulfate, ammonium nitrate or magnesium-based salts.

If your steps are being replaced, the guidance for exterior slabs exposed to freezing and deicers calls for air-entrained concrete with about 6 percent total air, a 4000 psi specified strength, and a broom finish without a steel trowel (NRMCA). Ask your contractor what mix they plan to use and why.

Do you need a permit?

Possibly. The City's list of work that needs no building permit covers a concrete or brick sidewalk, patio or walkway that is not in the public way, no more than 30 inches above adjacent grade, and not over a basement or story below (City of Chicago). Steps and stoops do not always fit that description. If yours are high, over a space below, or attached in a structural way, check with the Department of Buildings before you assume you are exempt.

When a permit applies, here is what we can confirm. The City's Express masonry permit covers concrete repair up to 100 square feet without drawings, and up to 5,000 square feet with drawings (City of Chicago). Concrete repair over 100 square feet needs plans from an Illinois-licensed architect or engineer (City of Chicago). Reconfiguring concrete elements is not eligible for Express (City of Chicago).

If the work touches the public way, for example steps that meet the sidewalk, that needs a CDOT permit separate from the building permit (City of Chicago). Owners of a primary residence of three stories or fewer and six units or fewer may act as their own contractor on one property per year (City of Chicago). See do you need a permit to pour concrete in Chicago for the wider picture. Rules change, so confirm with the Department of Buildings.

What drives the cost?

We do not quote numbers in an article. These are the drivers:

What should you ask a contractor?

1. Is the damage on the surface, or is the base failing?
2. If you repair it, how long do you expect it to hold, and what would make it fail?
3. If you replace it, what is going under the new concrete?
4. What mix will you use, and what about the finish?
5. Does this need a permit, and who pulls it?

Our concrete crew can look at the steps and tell you straight which side of the line they are on. See the Chicago concrete and sidewalk guide for the bigger picture.

Common questions

This article explains general rules and common situations in Chicago. It is not legal advice, and City rules change. For a specific property, check with the Chicago Department of Buildings or a licensed professional.