Rot Repair Rebuild: Ledger Attachment, Guard Geometry, and Schedule Pressure
A homeowner in a 1980s subdivision is rebuilding a 12 ft by 16 ft pressure-treated deck that was torn off after rot was found at the house wall. The deck serves a second-floor sliding door and stands 9 ft 6 in above grade at its outer edge. The contractor proposes to attach a 2x10 ledger to the existing rim board with 1/2 in lag screws at 12 in on center, staggered top and bottom, driven through 7/16 in oriented strand board sheathing. No flashing is detailed; the contractor argues the deck sits under a 24 in roof overhang and "will never see water." Two 6x6 posts bear on concrete piers 36 in below grade, and the built-up beam is 2 ft from the house. Guard posts are through-bolted to the rim joist with two 1/2 in bolts each. The guard top measures 37 in above the deck surface, with nominal 2x2 balusters at 6 in on center. The stair handrail measures 36 in above the nosings. The contractor is pressing for same-day approval so the concrete truck can place pier pads in the morning.
1. Is the ledger attachment as described acceptable? Identify what must be verified before any approval is given.
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Attachment cannot be approved on the contractor's description alone, for three reasons.
First, fastener size and spacing come from the residential deck provisions (the lag screw table keyed to joist span and ledger size), not from habit. Twelve inches on center is one possible row, but only for particular span and ledger combinations, and the table also fixes minimum edge distance and penetration. Verify the actual span, the ledger size, and that the screws engage the band joist or rim board with adequate penetration rather than bottoming in the sheathing thickness.
Second, confirm the ledger is not attached to a cantilevered floor system. Where the floor cantilevers at that wall, the deck must be self-supporting and the ledger must not be relied on.
Third, flashing at the wall-to-ledger joint is mandatory. A roof overhang is not a substitute; the detail must include flashing over the ledger, integrated with the water-resistive barrier and drained. Require a submitted detail or a design professional's letter, then re-inspect before framing.
2. Evaluate the guard, baluster spacing, handrail, and guard-post attachment against the residential code.
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Guard height is compliant: 37 in exceeds the 36 in minimum measured vertically from the deck surface. Handrail height is also compliant at 36 in, which falls inside the 34 in to 38 in band measured vertically above the tread nosings, provided it is graspable, continuous, and returns at the ends.
Baluster spacing fails. Nominal 2x2 members at 6 in on center yield roughly 4.5 in of clear opening. The guard must reject a 4 in sphere, so anything over 4 in clear is a defect; on the open side of the stair the tighter 4-3/8 in sphere applies and 4.5 in still fails by an eighth of an inch. This is exactly the kind of marginal field dimension that must be measured with a tape at several locations, not estimated from the plans.
Guard-post attachment is not verifiable by eye. Through-bolting to a rim joist must resist a 200 lb concentrated load in any direction; require the manufacturer's connector or an engineered detail with blocking, then inspect after installation.
3. The contractor asks you to approve only the pier footings today and "deal with the rest later." How do you respond, and what do you document?
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Splitting the inspection is legitimate; splitting the standard is not. The pier excavations and pad placement are a discrete inspection item that can be approved on its own merits once depth, bearing soil, and footing size are verified, because concrete placement is irreversible and there is no reason to hold it hostage to a framing dispute.
Everything above the piers stays unapproved. Issue a written correction notice, item by item: ledger fastener schedule and edge distance unverified; no flashing detail; guard baluster clear opening approximately 4.5 in against a 4 in sphere; guard-post attachment not substantiated. Reference the applicable code sections and the edition in force. Record the date, the individuals present, and photographs of the measured dimensions.
Do not accept a verbal promise to fix it, and do not describe the deck as "approved pending." State clearly that a separate framing and final inspection is required before the deck is used, and note in the record that the concrete approval covers only the foundations.