Concrete is the best material to use for steps because it remains rigid and keeps its form. Over time, however, it can deteriorate especially when de-icing salts are used. A set of concrete steps is also extremely heavy and if the subgrade is at all soft, the entire staircase or large portions of it can settle. Removal and replacement of concrete steps can be very tricky because alternate walking routes are not always readily available.
- Lay out and mark the areas to be removed and replaced.
- Set up warning barriers to make the work site safe.
- Construct a temporary staircase, if necessary, using wood.
- Saw cut the perimeter of the repair area to produce smooth, even edges.
- Excavate the deteriorated concrete and haul to a recycling facility.
- If the subgrade is soft or in poor condition, remove to a minimum depth of 4″ and replace with crushed stone. Stone should be leveled and compacted thoroughly using a vibratory tamper.
- Install 6 x 6 #10 welded wire mesh or 1/2″ steel rebar in a criss-cross pattern. If rebar is installed, it should be tied together to form a single unit.
- Set concrete forms using metal or wood forms pinned at sufficient intervals to keep the forms from disfiguring or “blowing out” when the concrete is introduced. Care should be taken in placement of the concrete forms to produce uniform steps and risers. Inconsistency in steps can easily cause people to trip and fall.
- Pour steps using 3000 psi or 4000 psi air entrained concrete. Air entrainment is for exterior concrete only and helps the concrete endure changing weather conditions.
- Trowel the concrete level.
- Wait for the concrete to partially set and then strip the face forms from the steps, so they can be finished as well.
- A broom finish should be applied perpendicular to the direction of traffic.
- The side forms should remain in place (sometimes overnight) until the concrete is hard.
- Once concrete has set, forms are to be stripped and removed from the site. Any available dirt from on site can be used to backfill the voids where forms were.
- Remove any remaining trash or debris.