Structural damage in apartment staircases doesn’t always announce itself with dramatic failure. More often, it develops gradually — corrosion eating away at hidden steel, concrete slowly losing its integrity, connections weakening over thousands of loading cycles. By the time the damage becomes obvious to an untrained eye, the staircase may already be in a dangerous condition.
Here are the five warning signs that indicate potential structural damage in apartment staircases — and what to do if you spot them.
1. Rust Bleeding Through Paint or Coating
When you see orange-brown rust stains bleeding through paint on steel stair components, the corrosion isn’t just on the surface — it’s been active underneath the coating for some time. Paint and coatings fail first where steel is thinnest, where moisture accumulates, and at edges and welds where the coating is naturally thinner or has been mechanically damaged.
The critical areas to watch: the bottom flange of steel stringers (where water runs and pools), base plates where steel meets concrete, weld joints (which have different metallurgy and corrode at different rates than the base metal), and any hardware — bolts, nuts, connection plates. Rust bleeding in these areas suggests the structural steel has been corroding for years.
What to do: Don’t just repaint. Have the affected areas professionally inspected to determine how much cross-section the steel has lost. A stair system that looks fine after a fresh coat of paint may have structural members that have lost 30-50% of their original thickness to corrosion.
2. Visible Deflection Under Normal Foot Traffic
A steel staircase that moves visibly when one person walks on it has a structural problem. Properly designed exterior stairs should show no perceptible deflection under normal loading. If you can see the staircase bounce, sway, or shift when people use it, the structure is either underdesigned for its current load, has lost capacity due to corrosion, or has a connection failure.
Test for this by standing at the base of the staircase and watching while someone walks up. Look for any visible movement, especially at the mid-span of flights and at landings. Then stand on a landing and shift your weight side to side — any lateral movement indicates a problem with the bracing or connections.
What to do: This is a safety priority. Restrict access to the staircase if the deflection is significant, and get a professional structural assessment immediately. Deflection under normal load means the staircase is operating beyond its safe capacity.
3. Cracked Welds at Connection Points
Welded connections are the joints of a steel stair system. They transfer load between members — from treads to stringers, from stringers to landings, from landings to the building structure. When a weld cracks, that load path is compromised.
Weld cracks are caused by fatigue (repeated loading over decades), corrosion (which creates stress concentrations), poor original weld quality, and thermal cycling (expansion and contraction from temperature changes). In Utah, the extreme temperature range — from well below zero in winter to over 100 degrees in summer — puts significant thermal stress on welded connections.
What to do: Cracked welds can often be repaired by a qualified welder, but the repair needs to address the root cause — not just lay new weld over the cracked area. If multiple welds are cracking throughout the system, it may indicate systemic fatigue, and replacement may be more appropriate than chasing individual repairs.
4. Concrete Delamination with Exposed Rebar
Delamination is when the surface layer of concrete separates from the layer below it. In stair treads and landings, this happens when moisture penetrates to the rebar, causes it to rust and expand, and the expanding rust pushes the concrete layers apart. The result is concrete that sounds hollow when tapped, loose pieces that can break off underfoot, and eventually exposed rebar.
Exposed rebar is a clear indicator that the concrete has failed its primary job of protecting the reinforcing steel. Once rebar is exposed, corrosion accelerates rapidly, and the remaining concrete loses its structural contribution. This process is self-reinforcing — the more the rebar corrodes, the more concrete it pushes off, exposing more rebar.
What to do: Individual treads with delamination and exposed rebar need replacement rather than patching. Concrete patch products don’t bond well to corroded rebar and will fail again quickly. If multiple treads on the same staircase show delamination, plan for a complete tread replacement.
5. Separation Between the Staircase and the Building
Exterior staircases are typically attached to the building at landing levels, with anchor bolts, embedded plates, or welded connections to structural steel in the building. When these connections fail, the staircase can begin to pull away from the building. This is one of the most serious structural conditions because it affects the entire staircase system, not just one component.
Look for: gaps between landing edges and the building wall that weren’t there before, caulk or sealant that has stretched or separated at stair-to-building joints, cracking in the building wall around anchor points, and any visible gap between embedded plates and the building structure.
What to do: This is an emergency condition. Any separation between the staircase and the building means the connection is failing, and the staircase could become unstable without warning. Restrict access and get a professional assessment immediately.
Next Steps
Identifying these warning signs early is the best way to prevent emergencies, control costs, and protect your tenants and your liability position. If you’ve noticed any of these conditions at your apartment complex or multi-family property in Utah, The Weld Pros provides free on-site structural assessments along the entire Wasatch Front.
Call (385) 286-7355 or request your free assessment online. We’ll inspect, document, and give you straight answers about what needs attention and what can wait.