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Wall penetrations, hose bibs, and linesets
Hose bibs, AC linesets, electrical conduit, and dryer hoods are holes in the wall, not attic vents. Where Oregon R327 is adopted, R327.3.2 covers ventilation openings for enclosed attics, enclosed soffit spaces, enclosed rafter spaces, and underfloor spaces (amendment PDF). It does not name those small penetrations. FEMA P-737 treats utility penetrations as gaps that can pass heat, hot gases, and embers. Seal them. Do not mesh the dryer because a wildfire checklist said to cover the vents.
You are at the hose bib. There is a ring of daylight around the pipe, or a plastic escutcheon that does not touch the siding. The same gap shows up at the AC lineset, the electrical mast, and the dryer hood. That is not an 8165 vent.
No g3-passed exhibit exists for this joint. Read the FEMA utilities chapter and the R327.3.2 sentence. Do not use a house-level hub graphic as the detail.
Why it matters
FEMA says most exterior equipment needs a building-envelope penetration for ducting and conduit. Those openings can ignite interior combustibles. A tight wall covering with a raw annulus at every pipe is not a tight wall. The wall still has to meet R327.3.3. See wall covering termination.
Presenters at the 25 June 2026 Central Oregon seminar said mechanical openings such as bath fans, fireplaces, and fresh-air intakes sit outside R327.3.2. That is event testimony, not a BCD ruling. See the mechanical-vents finding.
How the holes split
| Hole | What decides it | Common false shortcut |
|---|---|---|
| Attic, soffit, rafter, underfloor vent | R327.3.2 mesh or a vent designed to resist embers and flame | Treating a dryer hood as this row |
| Forced-air outlet (dryer, central vacuum) | IBHS flap, not mesh. R327.3.2 does not name it | 1/8 inch mesh on the hood |
| Plumbing vent | IBHS excludes it from the mesh-or-listed rule | An 8165 eave-vent SKU |
| Utility pipe, conduit, lineset, equipment | FEMA seal the annulus. Not an R327.3.2 vent | Foam leftover from weatherization as a fire listing |
| Garage door perimeter | Weatherstrip. See garage doors | Calling the door a vent |
Mesh versus listed vents is the attic and crawlspace choice. This page is the leftover holes.
The paths
1. Building ventilation (R327.3.2). Where the section applies, cover the opening with noncombustible corrosion-resistant metal mesh 1/16 to 1/8 inch, a vent designed to resist burning embers and flame, or other approved materials. Underside eave openings have their own ban and exceptions. That is not a hose bib.
2. Dryer and other forced-air outlets. IBHS wants a working louver or flap, not mesh. Lint on mesh is fuel. Plus wants the outlet noncombustible, for example metal. FEMA says replace non-fire-rated dryer wall louvers with noncombustible or fire-resistant louvers that open and close. The listed ASTM E2886 vents on this site are building ventilation, not dryer hoods. See dryer vents versus mesh.
3. Utility penetrations (FEMA, not an R327 subsection). If the connection cannot go below grade, FEMA says seal gaps in exterior walls and roofs with fire-resistant caulk, mortar, or fire-rated expanding foam. Large gaps get intumescent or fire-protective sheets or pillows. Fire-resistant wrap may go around wall-penetrating equipment such as air conditioners. Sealants and mortar have to come out and go back when a cable or pipe is reinstalled. That is a builder guide, not a listing ID.
4. Joints around a listed vent (IBHS). Where you use the performance-path vent, seal joints per the manufacturer’s installation instructions so embers and flame do not go around the frame. Caulk around the vent is not a substitute for the vent.
5. California. CWUIC is a different book. This page does not invent a hose-bib subsection in Chapter 5. Read that book on a mapped California lot.
What people mix up
- Meshing the dryer because the attic rule said “all vents.”
- Specifying an 8165 eave vent as a lineset hood or a hose-bib cover.
- Treating leftover weatherization foam as an R327 wall path. Coatings are not on the R327.3.3 list. See the coatings finding.
- Calling a plumbing stack an ember vent.
- Leaving a gap at the hose bib and calling the wall covering complete.
How to check
- Confirm whether R327 is adopted for the lot. The Oregon vent sentence still does not name these holes.
- Walk every pipe, conduit, lineset, dryer hood, bath fan, and electrical penetration. Look for daylight around the sleeve.
- Stand at the dryer separately. A flap, not mesh, if you are scoring IBHS.
- If a listed building vent is in the wall, check the joint around the frame, not only the mesh.
- Put the product and the seal on the drawings. A “per code” note does not name the hole.
Limits
This page does not spec a caulk SKU or an intumescent pad listing. It does not size a dryer duct. It does not decide propane-tank clearances. FireApproved is not the AHJ. FEMA P-737 is a builder guide. IBHS is a designation. R327, where adopted, is a new-construction code.
Related records
Questions
Does R327 require fire caulk at every hose bib?
No. R327.3.2 covers ventilation openings for enclosed attics, soffits, rafter spaces, and underfloor spaces. It does not name hose bibs, linesets, or electrical conduit. FEMA P-737 says seal utility penetrations with fire-resistant caulk, mortar, or fire-rated expanding foam. That is guidance. Confirm with the official.
Can I put 1/8 inch mesh on the dryer hood?
Not if you are following IBHS Wildfire Prepared. Forced-air outlets such as dryers need a working louver or flap, not mesh. Mesh collects lint. See dryer vents versus mesh.
Is an ASTM E2886 listed eave vent a dryer or a lineset cover?
No. The listed vents on this site are building ventilation. They are not a hose-bib escutcheon, an AC lineset hood, or a dryer outlet.
Do plumbing vents need ember mesh?
IBHS excludes plumbing vents from the mesh-or-listed-vent rule. Oregon R327.3.2 still does not name them as attic vents. Do not treat a roof plumbing stack as an 8165 listing.