Yavapai County's 2025 building code amendment (effective 1/1/26)
requires ridge ventilation on all new tile installations on
pitches steeper than 2/12. Mortar-bedded ridges are now considered
"decorative finish" — fine for aesthetics, but a separate ridge
vent must be installed underneath.
Why the change
Tile-roofed attics in Northern AZ run hotter than shingle-roofed
attics. Without ridge ventilation:
- Attic temperatures can hit 165°F+ in summer (vs 130°F with vents)
- Underlayment ages 30-40% faster
- Cooling costs run 8-15% higher
- Ice damming risk increases (warm attic melts snow that refreezes
at cold eaves)
What the new code requires
For new tile installs on 2/12+ pitch in Yavapai:
- Continuous ridge vent running the full ridge length
- Soffit ventilation at minimum 1 sq ft per 150 sq ft attic
- Net free ventilation area of 1:300 (1 sq ft vent per 300 sq
ft attic floor)
- Mortar bedding allowed only as decorative top layer over
the ridge vent
Cost adder vs traditional mortar-bedded
| Component | Old (mortar-bedded) | New (vented) | Adder |
|-----------|--------------------|--------------|-------|
| Ridge cap labor | $1,200 | $1,800 | +$600 |
| Vent components | — | $400 | +$400 |
| Soffit retrofit (if needed) | — | $800-$1,500 | +$800-$1,500 |
Total adder: $1,800-$2,500 on a 2,200 sq ft tile install.
Net annual savings (cooling + underlayment life): ~$200-$350/yr.
Payback: 6-9 years.
What if you have a mortar-bedded tile roof now?
No retrofit required unless you trigger a major-repair threshold.
Plan for it on the next re-tile.
Signs your unvented tile roof is causing problems:
- Discolored attic insulation
- Curling underlayment edges visible at eaves
- Higher-than-expected summer cooling bills
- Ice damming during winter cold snaps
Sedona + Prescott historic-district exception
Some Sedona + Prescott historic-district HOAs prohibit visible
ridge vents because they break the "Old World" tile profile.
The 2025 code includes a hardship variance — apply through the
HOA + Yavapai planning department.