Spot the Violation

FramingFire separation, egress & alarmsLevel 12018 IRC

Door from the garage into the house

Inside an attached garage, looking at the taped drywall wall shared with the house. A flush wood-veneer slab door at the top of a two-step concrete stoop leads into the house. It has a lever handle, a deadbolt and an overhead door closer. Low on the door, the face veneer is punched through in a ragged hole, and the hole shows an empty interior with a thin cardboard honeycomb grid behind the thin skin. Garbage and recycling carts stand to the left, a steel shelf with paint cans to the right, and the front bumper of a parked car is in the lower left corner.
Attached garage, door into the house

What's wrong here?

  1. The door between the garage and the house is a hollow-core door
  2. The door must be a steel door
  3. The garage floor must be at least 4 in. below the house floor at the door
  4. Nothing. This installation is compliant
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Show the answer and the code reference

The answer

The door in the wall between the garage and the house is a hollow-core wood door. R302.5.1 requires a solid wood or steel door at least 1-3/8 in. thick, or a 20-minute fire-rated door.

Correct choice: 1. The door between the garage and the house is a hollow-core door

The wall between an attached garage and the house is the dwelling's fire separation. Garages hold cars, gasoline and solvents, and they are where a lot of house fires start. A hollow-core door is two thin veneer skins over a cardboard grid, and fire burns through it in a few minutes. R302.5.1 limits openings in that wall to solid wood doors at least 1-3/8 in. thick, solid or honeycomb-core steel doors at least 1-3/8 in. thick, or doors labeled 20-minute fire-rated, and it prohibits any opening from the garage directly into a sleeping room. The hole where something hit the door shows what the door is made of. The drywall on the garage side and the closer are fine.

How to fix it

Replace the slab with a solid-core wood door at least 1-3/8 in. thick, a 1-3/8 in. solid or honeycomb-core steel door, or a labeled 20-minute fire-rated door. Rehang it with the closer, and keep the weatherstripping and threshold tight.

Code references

  • IRC 2018 R302.5.1 — Opening protection

    Openings from a private garage directly into a room used for sleeping are not permitted. Other openings between the garage and the residence must have solid wood doors at least 1-3/8 in. thick, solid or honeycomb-core steel doors at least 1-3/8 in. thick, or 20-minute fire-rated doors, equipped with a self-closing device.

    Drills citing R302.5.1

  • IRC 2018 R302.6 — Dwelling-garage fire separation

    The garage must be separated from the residence and its attic by not less than 1/2 in. gypsum board applied to the garage side (Table R302.6), with 5/8 in. Type X gypsum board on a garage ceiling that has habitable rooms above it.

    Drills citing R302.6

2024 IRC:not yet checked Confidence: low

Minnesota

MN status unverifiedConfidence: low

Minnesota adopts the 2018 IRC with Minnesota amendments as the Minnesota Residential Code (Minn. Rules ch. 1309). Whether Minn. Rules 1309.0302 amends R302.5.1 could not be confirmed: Minnesota is reported to have removed the self-closing device requirement for this door, so check the Minnesota text before writing up a missing closer. The door construction requirement this drill tests (1-3/8 in. solid wood, 1-3/8 in. solid or honeycomb-core steel, or 20-minute fire-rated) is not known to be changed, and the closer question does not affect this drill because the door has one. DLI is adopting the 2024 IRC as the next edition; see the 2024 IRC note.

About the Minnesota Residential Code

Citation under review. The 2018 R302.5.1 door options and self-closing device wording are from the verifier's knowledge and are well established. Open item: whether Minn. Rules 1309.0302 amends R302.5.1 (reported deletion of the self-closer), which sets the Minnesota status; revisor.mn.gov could not be fetched. Also confirm the 2024 IRC section and closer wording.

Why the other choices are wrong

  • The door must be a steel door. R302.5.1 allows a solid wood door at least 1-3/8 in. thick, a solid or honeycomb-core steel door at least 1-3/8 in. thick, or a 20-minute fire-rated door. Solid wood is fine; hollow-core wood is not.
  • The garage floor must be at least 4 in. below the house floor at the door. The IRC has no step-down requirement at the garage door. R309.1 requires a noncombustible garage floor sloped toward the main vehicle entry, and many garages here happen to have a step, but a step is not required.
  • Nothing. This installation is compliant. The hole shows a hollow interior with a cardboard honeycomb core, so this is a hollow-core wood door. R302.5.1 does not accept it in the wall between a garage and the house.
Safety hazardLevel 1 · Apprentice#garage#fire separation#door#hollow core

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