FireApproved
On this page
  1. Why it matters
  2. How the lists split
  3. The paths
  4. What people mix up
  5. How to check
  6. Limits
  7. Related records

Home / Guides / For builders — detailing / Plastic skylights under R327 and CWUIC

Plastic skylights under R327 and CWUIC

Last verified 2026-08-24.

A plastic dome is not on Oregon’s skylight list. Where R327 is adopted, R327.3.6 treats skylights with exterior windows. The paths are tempered glass, multilayered glazed panels, glass block, or a 20-minute rating (amendment PDF). California CWUIC 504.8 puts skylights on its glazing menu. Operable skylights there also need 1/8 inch noncombustible mesh.

You are on the roof looking at a yellowed plastic bubble. Heat and embers hit that hole before they hit the attic vents.

DET-021 is not published. The four Oregon window paths live on dual-pane versus tempered. DET-019 is that menu. This page is the roof hole.

Why it matters

A skylight is a window in the roof. Plastic can fail in heat that glass would ride out. The flashing around it is a roof-to-wall problem. See roof-to-wall and dormer cheeks.

How the lists split

BookSkylight
R327.3.6Tempered, multilayered glazed panels, glass block, or 20-minute. No plastic dome on the list
CWRC 404.7Same four-item menu on Class 2 lots. No plastic dome. No operable-mesh sentence. Class 1 does not add this rule
CWUIC 504.8Same family of glazing paths, plus 1/8 inch mesh on operable units
IBHSRead the current technical standard for glass. Do not invent a plastic-dome pass

Do not cite a private BCD email that energy-code windows suffice.

The paths

1. Oregon. Replace the plastic dome with one of the four R327.3.6 products. Put the product on the drawings.

2. Colorado Class 2 lot. CWRC 404.7 is the same four-item menu, including skylights. It does not add California’s operable-mesh sentence. Confirm the local ordinance.

3. California mapped lot. Read 504.8. If it opens, add the mesh.

4. Flash the curb. FEMA wants flashing at roof protrusions such as skylights. That is weather and embers.

What people mix up

  • Dual-pane plastic as multilayered glass.
  • Skipping operable-skylight mesh in California.
  • Treating the skylight as a ridge vent.

How to check

  1. What is the dome. Glass or plastic.
  2. Which of the four Oregon paths, which CWRC 404.7 path on a Class 2 Colorado lot, or which CWUIC 504.8 path.
  3. If it opens, is there 1/8 inch mesh on a California job.
  4. Look at the flashing.

Limits

DET-021 is not published. This page does not spec a curb SKU. FireApproved is not the AHJ.

Questions

Can I keep a plastic bubble skylight where R327 is adopted?

R327.3.6 names tempered glass, multilayered glazed panels, glass block, or a 20-minute fire rating for exterior windows, windows in doors, and skylights. A plastic dome is not one of those four. Confirm with the official before you assume a greenhouse panel is multilayered glass.

Is dual-pane annealed glass enough for a skylight in Oregon?

The four R327.3.6 paths do not say “dual-pane.” Dual-pane versus tempered is a different guide. Do not import a private BCD email about energy-code windows.

What about an operable skylight in California?

CWUIC 504.8 includes skylights on the glazing menu. Operable skylights also need 1/8 inch noncombustible mesh. That mesh rule is not R327.3.6.

Sources