Crumbling concrete steps
moderate 2–5 h
Tools: hammer and cold chisel, wire brush, shop vacuum, trowel and edging tool, plywood offcuts and clamps for forms, bucket · Materials: vinyl-modified concrete patch or quick-setting concrete for corners, bonding agent, concrete sealer
Steps
- Chisel away every loose piece until you hit solid concrete that rings when tapped; a patch on crumbling concrete falls off within a season.
- Undercut the edges of the repair slightly so the patch locks in, then brush and vacuum out the dust and dampen the surface.
- For a broken step edge or corner, clamp a plywood form flush with the old face so the new concrete takes the original shape.
- Brush on a bonding agent and pack in the patch mix while it is tacky, pressing hard to fill the corners; slope the tread slightly forward to shed water.
- Strike off with a trowel, round the front edge with an edging tool to match the other steps, and keep the patch damp under plastic for two days.
- Once cured for a month, seal all the steps and stop using salt on them — sand for ice from now on.
Stop and call a pro if
- a step rocks, has a crack right through, or the whole flight has settled or tilted
- exposed rebar is rusting and lifting the concrete
- the steps are the only entrance and the damage makes them unsafe to use while a patch cures
What a pro does that you can't
A concrete mason rebuilds the front edges with proper reinforcement, resurfaces the flight so the treads match, or replaces steps that have settled, and can add a rail where code requires one.
DIY cost: $30–80 in patch, bonding agent and sealer