Rear Egress Stair Replacement at a Two-Family
A 1926 two-family house has a single rear exterior wood stair serving the second-floor apartment. The stair rises 8 ft 4 in. from a concrete pad to a small landing at the back door. Measured risers vary from 7 1/2 in. to 8 1/4 in.; treads are 9 1/2 in.; clear width is 34 in. between stringers. The landing is 30 in. deep in the direction of travel, the door swings out over it, and the guard is 32 in. high with balusters spaced about 6 in. on center. The stringers bear on a 4x4 post set on grade, and the handrail is a single 2x4 on the wall at 30 in. The owner wants to replace only the deck boards and loose guardrail, insisting no permit is needed because 'nothing is changing size.' The upper unit is the owner's rental and the stair is its only exit. Winter is approaching and the tenant remains occupied.
1. The owner wants to replace only the deck boards and guardrail. What permit and code analysis should you provide before starting, and which deficiencies must be corrected as part of that scope?
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Start by separating cosmetic repair from alteration of the means of egress. Replacing deck boards alone may qualify as a minor repair, but replacing the guardrail is a safety-component alteration and normally requires a permit. More important, this is the only exit from an occupied rental, so the stair must remain usable during work and cannot be left open or blocked overnight.
If the scope includes stringers, risers, treads, landing, or guard, treat the stair as reconstructed and bring it to current Michigan Residential Code dimensions. For new stairs, the clear width must be at least 36 in.; risers generally cannot exceed 7 3/4 in.; treads must be at least 10 in.; adjacent riser variation is limited to 3/8 in.; handrails must be graspable and about 34-38 in. above the tread nosing; guards at the landing must be at least 36 in. high with openings that will not pass a 4 in. sphere. The 30 in. landing is too shallow for the door swing and travel, and the post bearing on grade is not a frost-depth footing. The 8 1/4 in. riser and 9 1/2 in. tread already fail new-stair geometry.
If the owner truly limits work to surface boards, do not use that limit to replace the guard with the same 32 in., 6 in. opening assembly. The guard replacement must correct height and baluster spacing, and the permit application should state the full scope. If structural stringers are exposed or replaced, expect the inspector to require full stair compliance. Document existing conditions with photos and measurements before demolition.
2. How would you sequence the work and inspections so the upper unit always has a legal escape route?
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Sequence the job around maintaining a second means of escape, not around the crew's convenience. Before demolition, confirm whether the tenant can use an interior stair or a temporary exterior stair that meets egress requirements. If the rear stair is the only exit, do not remove treads and guardrail for an extended period without an approved temporary stair and a written plan accepted by the building official.
A practical sequence is: obtain the permit; meet the inspector on site to agree on existing versus new work; install any temporary egress stair and guard; demolish only the portion being replaced; inspect footings and post bearing before backfill; frame stringers and landings; inspect framing and guard before decking; install treads, handrail, and guard; final inspection. Keep the lower landing and a continuous handrail available each night.
Because winter is coming, protect the work from ice and do not leave temporary openings unguarded. The tenant should receive written notice of work hours and any short periods when the rear stair is unavailable. If a compliant temporary route cannot be maintained, the work should be staged so the stair is out of service only while the crew is on site and the route is restored before leaving.