Cedar Shake to Architectural Shingle or Composite Roof Conversion in Utah
Converting a weathered cedar shake roof to Class A architectural or SBS impact shingles in Salt Lake County costs $6.75 to $9.85 per square foot installed—including heavy wood-shake tear-off, installing solid 7/16-inch APA-rated OSB sheathing over spaced 1x4 or 1x6 skip-battens, new eave/rake metal, and balanced ridge ventilation. Urban Design & Remodel (Utah DOPL #10146123-5501, (801) 440-1952) also installs luxury polymer composite shakes ($12.50–$18.50/sq ft) for strict HOA communities.
Across Olympus Cove, Emigration Canyon, Upper Millcreek, Holladay, and 1980s bench neighborhoods in Sandy and Bountiful, thousands of custom homes were originally crowned with hand-split Western Red Cedar shakes. While rustic when new, high-altitude Utah sun, bone-dry 15% summer humidity, and winter freeze-thaw splitting twist wood shakes into cupped, curled tinderboxes within 20 to 25 years. Today, property insurance carriers across the Wasatch Wildland-Urban Interface (WUI) actively non-renew policies on untreated wood shake roofs due to catastrophic canyon ember risk! Converting old cedar shakes to solid-decked Class A fire-rated dimensional shingles or synthetic composite shakes secures homeowners insurance while slashing maintenance.
Spaced 1x4 Skip-Sheathing to Solid 7/16" OSB Decking (IRC R905.2.1)
Unlike asphalt roofs nailed to continuous 4x8 sheets of wood, traditional Utah cedar shake roofs were installed over spaced 'skip-sheathing'—1x4 or 1x6 pine boards nailed horizontally across rafters with open 3-to-5-inch air gaps between every board so damp wood shakes could dry from underneath, interwoven with 18-inch strips of 30 lb felt. Under Utah Residential Code IRC R905.2.1, neither asphalt shingles nor most synthetic slate/shake systems can be nailed onto open gapped skip-sheathing. Once we strip messy cedar shakes, dry cedar dust, and interwoven felt rolls clean down to the 1x4 or 1x6 slats, we re-nail loose slats to rafters and install staggered 4x8 sheets of 7/16-inch or 15/32-inch APA Exposure 1 OSB with 8d ring-shank nails across the entire roof.
- Full 7/16" or 15/32" OSB re-decking bridges 4-inch skip-sheathing gaps for 100+ lb nail hold
- Adds immense lateral seismic & wind diaphragm shear stiffness to 1970s–1980s custom roof framing
- Heavy-duty attic & landscape tarping contains decades of fine brown 'shake dust' falling through slats
Solving the Ventilation Shift When Sealing Open Skip-Sheathing
Here is a critical building-science detail inexperienced roofers miss during Utah shake-to-shingle conversions: old cedar shake roofs 'breathed' effortlessly across every square foot of open 1x4 skip-sheathing, so 1980s builders rarely installed adequate soffit intake or ridge exhaust vents! The moment you sheet over open skip-sheathing with solid OSB and synthetic underlayment without adding mechanical airflow, summer attic temperatures jump 35°F and winter bathroom humidity turns to black frost mold on your brand-new OSB panels. As standard practice on every cedar conversion, Urban Design & Remodel calculates exact attic square footage under IRC R806.2, cuts continuous 2-inch ridge-vent exhaust slots at peaks, and opens soffit intake channels to guarantee balanced airflow.
- Prevents sudden post-conversion attic overheating and winter OSB condensation frost
- Continuous baffled shingle-over ridge vent + eave soffit intake meets 1:150 IRC R806.2 code
- Raises fascia/gutter drip-edge plane by 7/16"—custom oversized D-metal hides OSB deck edge cleanly
WUI Class A Fire Protection & Insurance Savings on Wasatch Foothills
Municipalities bordering brush-covered foothills—including Salt Lake City Foothill/Emigration WUI zones, Draper SunCrest, Sandy east bench, and Summit/Morgan corridors—enforce Utah Wildland-Urban Interface Code requiring Class A non-combustible roof coverings on replacements, banning untreated wood shakes outright. Even outside mapped WUI zones, Utah homeowners insurers surcharge wood shake policies by $1,200 to $3,500 per year or issue outright cancellation notices! Converting to UL 790 Class A fiberglass-mat architectural shingles (such as Presidential Shake TL luxury laminate, Malarkey Legacy Class 4 SBS, or Owens Corning Duration) or Class A polymer composite shakes immediately restores mainstream carrier eligibility and slashes annual insurance premiums by 20% to 45%.
- UL 790 Class A fire rating blocks wind-blown canyon wildfire embers from igniting roof decks
- Typical Utah insurance savings: $1,200–$3,500/yr + immediate eligibility with preferred carriers
- Grand Manor & Presidential Shake TL multi-layer asphalt shingles mimic thick wood shadow lines
2026 Utah Cedar Shake Conversion Cost Breakdown (Shingle vs. Composite)
Cedar shake tear-offs require roughly double the dump-trailer volume and disposal labor of flat asphalt shingles because split wood shakes puff up bulky with thousands of long hand-driven box nails and decades of pine needles. Across Salt Lake County in 2026, tearing off cedar shakes, installing full 7/16-inch OSB re-decking ($2.25–$2.85/sq ft portion), adding ice-and-water shield, cutting ridge ventilation, and installing heavy dimensional or Class 4 SBS asphalt shingles runs $6.75 to $9.85 per square foot complete. Stepping up to ultra-thick luxury tri-laminate 'shake-look' asphalt shingles (CertainTeed Presidential TL) runs $9.50 to $12.25/sq ft, while true Brava or DaVinci synthetic composite cedar shakes run $13.50 to $19.50/sq ft.
- Cedar tear-off + 7/16" OSB re-deck + Class A architectural/SBS shingles: $6.75–$9.85/sq ft
- Luxury tri-laminate 'Presidential Shake' asphalt conversion (incl. OSB deck): $9.50–$12.25/sq ft
- Attic drop-cloth protection recommended over open garage items beneath gapped 1x4 slats
2026 Utah Cedar Shake Conversion Options: Cost, Fire Rating & Curb Appeal
| Replacement System (Incl. OSB Deck) | Installed Utah Cost / Sq Ft | Fire & Hail Rating | Visual Match to Original Cedar |
|---|---|---|---|
| Architectural / SBS Shingle + OSB | $6.75 – $9.85 / sq ft | Class A Fire / Class 3–4 Hail | Clean dimensional profile (Best Value) |
| Presidential Tri-Laminate + OSB | $9.50 – $12.25 / sq ft | Class A Fire / UL 2218 Opt. | Deep notched sawtooth wood shadow |
| Stone-Coated Steel Shake + Deck | $11.50 – $15.50 / sq ft | Class A Fire / Class 4 Hail | Textured timber-grain steel panels |
| Brava / DaVinci Composite + OSB | $13.50 – $19.50 / sq ft | Class A Fire / Class 4 Hail | Virtually indistinguishable hand-split cedar |
Grant Helmer's Utah Field Pro-Tip (DOPL #10146123-5501)
Warn your family before tear-off morning on a cedar shake conversion (Utah DOPL #10146123-5501): forty years of dry cedar dust and granulate trapped between open 1x4 skip-sheathing boards WILL sift down into your attic and unfinished garage rafters when old shakes come off! We lay poly tarps over stored attic/garage belongings and vacuum access landings clean afterward.
Frequently Asked Questions: Convert Cedar Shake Roof To Asphalt Shingles Utah
Can roofers nail new OSB right over existing 1x4 skip-sheathing without removing the 1x4s?
Yes—and leaving sound 1x4 or 1x6 boards in place is structurally superior! Removing firmly nailed skip-boards risks splitting dry 40-year-old truss top chords. Re-fastening the 1x4s and nailing 7/16-inch OSB across them with long 8d/10d ring-shank nails into rafters creates a rock-solid deck.
Will adding OSB and architectural shingles make my roof heavier than cedar shakes?
Only slightly, and well within Utah structural limits. Heavy wet cedar shakes plus thick interwoven 30 lb felt rolls weighed roughly 3.5 to 4.5 lbs/sq ft; 7/16-inch OSB (1.4 lbs/sq ft) plus architectural shingles (3.0 lbs/sq ft) totals ~4.4 lbs/sq ft while dramatically stiffening truss shear.
Why did my homeowners insurance drop my policy over a cedar shake roof in Holladay?
Insurance wildfire models treat weathered wood shakes on East Bench canyons as extreme ember-ignition liabilities. Converting to a UL 790 Class A fire-rated asphalt, steel, or synthetic composite roof immediately qualifies your property for standard preferred underwriting.
Do wall flashings and skylights sit differently after adding 7/16-inch OSB?
Raising the roof deck 7/16 inch plus removing 1-inch thick cedar shakes actually lowers finished roof surface height slightly! That reveals unpainted lines on brick chimneys and stucco walls, so we install taller 5x5 step flashing and fresh higher counter-flashing.
Related Utah Roofing, Bathroom & Remodeling Resources
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