Concrete Steps, Stoops and Retaining Walls

Steps

Rise, run, landing size, handrail, footing

Retaining walls

Footing, drainage stone, weep path, height

Code note

Low walls not over 4 feet (bottom of footing to top) and not holding a surcharge are listed as permit-exempt locally

Frost line

24 inches in the MABCD jurisdiction

Why steps fail

Most failing concrete steps around Wichita show one of three problems. The whole unit has settled and tipped away from the house, leaving a gap at the door. The edges and treads have scaled and crumbled from years of salt and freeze-thaw. Or the steps were built with uneven risers that people trip on. Each has a different fix.

Settling

Steps are heavy and often sit on backfill that was placed against the foundation when the house was built. Backfill settles. K-State Research and Extension notes that soil next to a foundation frequently settles over time and can even reverse the slope toward the house (K-State Research and Extension, MF2809 Dry Basements and Crawl Spaces). Add clay that shrinks in drought and swells in wet weather (K-State Research and Extension, Clay Soil: It Shrinks and Swells), and a stoop can drop or rotate. Rebuilt steps need a footing on firm soil, not on loose fill.

Frost

The Wichita-Sedgwick County building code sets the frost line for the Metropolitan Area Building and Construction Department jurisdiction at 24 inches below finished grade (Wichita-Sedgwick County Unified Building and Trade Code (MABCD)). Footings for permanent structures are designed to reach below it so frost cannot lift them. Ask how deep the step footing will go and what it sits on.

Scaling and crumbling

Steps are the most salted concrete on most properties. NRMCA ties scaling to non-air-entrained concrete, excessive de-icers on new concrete, poor finishing and weak curing (NRMCA, CIP 2: Scaling Concrete Surfaces). New steps should be air-entrained and cured well, and the first winter should be de-icer free.

Getting the geometry right

Every riser in a flight should be the same height and every tread the same depth. People's feet learn the rhythm on the first step; a step that is even slightly off is the one they trip on. The landing at the door should be large enough to stand on while a storm door swings open. If a handrail is wanted or required, plan the anchors before the pour, not after. Building codes set limits on rise, run and when a guard or handrail is required; ask the estimator which apply.

The joint at the house

NRMCA recommends isolation joints between slabs and walls or footings (NRMCA, CIP 6: Joints in Concrete Slabs on Grade). Steps should be separated from the foundation so they can move without cracking the wall or pulling away in one piece. A sealed joint keeps water from running down behind the steps toward the basement.

Retaining walls

Low walls hold soil where a yard changes level: beside a driveway cut into a slope, along a patio edge, or around a raised bed. Concrete walls can be poured in forms or built from block. Either way, three things decide whether a wall stands straight:

1. A footing wide and deep enough for the wall and the soil it holds.
2. Drainage behind the wall, usually free-draining stone and a path for water to escape. Saturated clay pushes hard and swells; water trapped behind a wall is the most common reason walls lean.
3. Honest height. Taller walls hold back more soil with more force.

The Wichita-Sedgwick County code lists retaining walls not over 4 feet in height, measured from the bottom of the footing to the top of the wall, among work exempt from a building permit unless the wall supports a surcharge such as a driveway or building above it (Wichita-Sedgwick County Unified Building and Trade Code (MABCD)). Walls taller than that, or walls holding up a load, call for a permit and often an engineered design. Other cities in the metro have their own rules.

Repair or rebuild?

Light scaling on otherwise sound steps can sometimes be patched or resurfaced; see concrete repair and resurfacing. Steps that have rotated, separated from the house or crumbled at the base usually need to be removed and rebuilt on a proper footing. A leaning wall rarely straightens with patching; the fix is usually to rebuild with drainage.

Safety in winter

Steps ice over first. K-State Research and Extension recommends calcium chloride as a first-choice de-icer and notes rock salt is documented to damage unsealed concrete and nearby plants (K-State Research and Extension, Choosing the Best Ice Melt Product). Sand gives grip without chemistry, and a breathable sealer helps; see ice melt and concrete scaling.

See the estimate factors page for what changes the scope of steps and walls.

Sizing up the job: see what changes the size of a steps or wall job on the estimate-factors page. It lists what moves the scope, never a price.

Further reading

• Call 811 Before Tearing Out or Digging for Concrete