Project Overview
- Service Type
- SB 721 Inspection · Structural Repair
- Location
- Folsom, CA
- Property Type
- Multi-Family Fourplex
- Timeline
- 8 working days
- Completed
- November 2025
Project at a Glance
The Problem
The fourplex's shared rear deck failed its SB 721 inspection on two counts: the original decking boards had gone soft with rot, and the joists beneath were undersized for current span requirements. Spot repairs would have left the owner facing the same findings at the next six-year cycle.
Span requirements come from the current California Building Code, which the original framing predated; the rebuild brought the assembly up to the standard referenced by HSC §17973. See our SB 721 inspection service for what inspectors check.
The Solution
Rather than patch, the owner chose a rebuild: we replaced and reinforced the framing to current code, then installed Trex composite decking on stainless hidden fasteners with redwood fascia. The material upgrade eliminated the rot-and-recoat cycle entirely.
The deck passed re-inspection on the first visit, and the composite surface carries a 25-year warranty — two full SB 721 cycles without a maintenance bill.
- Demolition of failed decking
- Joist replacement & reinforcement
- Trex composite decking installation
- Redwood fascia & trim
- SB 721 re-inspection & sign-off
How the Project Ran
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Findings review
The failed SB 721 report flagged rot-softened decking and joists undersized for current span tables — spot repairs would have carried both findings into the next cycle.
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Material decision
We priced redwood replacement against Trex composite over two six-year cycles; composite won on lifetime cost once recoating and board replacement were counted.
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Rebuild (Days 1–7)
Framing replaced and reinforced to current code, then Trex boards set on stainless hidden fasteners with redwood fascia trim.
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Re-inspection (Day 8)
Passed on the first visit; warranty and framing documentation went into the building compliance file.
Materials Used
- Trex composite decking 25-year warranty walking surface
- Pressure-treated framing joists sized to current code
- Redwood fascia perimeter trim
- Stainless hidden fasteners clean, corrosion-free deck face
Before & After
Passed re-inspection; maintenance-free surface warrantied for 25 years.
ABD walked me through the redwood-versus-composite math over two inspection cycles. Choosing Trex was obvious on paper, and the deck looks better than the original.
Questions About This Project
Is composite decking compliant for SB 721 buildings?
Yes — SB 721 governs the structural elements and waterproofing, not the surface material. Composite removes the rot-and-recoat cycle that causes most repeat findings.
Is Trex worth the premium over redwood?
On this fourplex the composite premium paid for itself before the next six-year inspection, counting recoating, board replacement and access costs that redwood would have required.
Will the deck pass future inspections more easily?
The framing is now sized to current code and the surface cannot rot, so future cycles reduce to checking connections and flashing — the quick part of an inspection.
