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Pergolas and patio covers as projections
A pergola is not a free pass because it has no shingles. Where Oregon R327 is adopted, patio covers sit in R327.3.4 with other overhanging projections. A patio or porch ceiling larger than 200 square feet and under 12 feet gets a numbered underside menu (R327.3.4.2). IBHS Base treats overheads on an attached deck as part of the footprint. Solid roofs there are Class A. Combustible slats may cover no more than 15 percent. A combustible gazebo on that deck sits 10 feet off the walls.
You are standing under slats that throw a stripe of shade on the deck. Needles sit on the beams. That structure is a projection.
No g3-passed pergola exhibit exists. Eave undersides live on Craftsman eaves and the 12-foot rule. Do not use a house-level hub graphic as this cover.
Why it matters
Embers and heat collect under covers the way they collect under eaves. A combustible roof over a hot tub is an IBHS miss even if the deck boards passed. See deck contents.
How the rules split
| Structure | Oregon R327 | IBHS Base |
|---|---|---|
| Patio / porch ceiling > 200 sq ft and < 12 ft | R327.3.4.2 underside menu | Attached overhead is footprint |
| Smaller or higher ceiling | Not that sentence. Still a projection under 3.4 if it is one | Same footprint rules if attached |
| Open slats | Official classifies the projection | ≤ 15 percent coverage, or Class A solid roof |
| Combustible gazebo on attached deck | Projection / accessory. Confirm | ≥ 10 ft from walls unless fully noncombustible |
R327.3.4.2 menu is noncombustible, ignition-resistant, Type X behind covering, 1-hour, or ASTM E2957. Trim boards excepted.
The paths
1. Oregon ceiling. Measure area and height. If you are in 3.4.2, pick a numbered underside path. Put it on the drawings.
2. IBHS overhead. Class A solid, or slats ≤ 15 percent. Posts get six inches of noncombustible at the base. No curtains. Retractable screens only with noncombustible housing.
3. Setback. Combustible overhead on the attached deck, 10 feet from walls, unless the whole thing is noncombustible.
4. Colorado. CWRC 404.6 sends appendages and projections to the Class 2 exterior-wall menu. It does not reprint Oregon’s 200 square foot ceiling sentence. Confirm the local ordinance.
5. California. CWUIC is a different book. Do not paste Oregon’s 200 square foot ceiling sentence without reading Chapter 5.
What people mix up
- “It is not a roof, so R327 does not apply.”
- Using the 200 square foot deck lumber exception as a pergola skip.
- Combustible shade cloth as slats.
- A gazebo against the slider.
How to check
- Is it attached. Is it over 200 square feet. Is any framing under 12 feet.
- Solid roof or slats. If slats, percent coverage for IBHS.
- Distance to the wall.
- What is under it. Tub, furniture, wood.
Limits
This page does not spec a fabric listing. FireApproved is not the AHJ. IBHS is a designation. R327, where adopted, is a new-construction code.
Related records
Questions
Is a pergola an R327 roof?
R327.3.4 lists patio covers with balconies, carports, decks, porch ceilings, and similar projections. A solid patio cover is that projection. Open slats are still a projection the official will classify. IBHS allows combustible slats that cover no more than 15 percent of the total surface area, or a Class A solid roof. Confirm with the official.
When does the patio-ceiling menu apply?
R327.3.4.2 protects the exposed underside of exterior patio and porch ceilings greater than 200 square feet and less than 12 feet above grade. Architectural trim boards are excepted. Smaller or higher ceilings are not that sentence.
Can I set a combustible gazebo on the attached deck against the house?
IBHS Base wants a detached combustible overhead on an attached deck at least 10 feet from exterior walls. Entirely noncombustible overheads have no setback in that sentence. Hot tubs also cannot sit under a combustible overhead.