Even barn dwellers need fire safety

Q : We built a small guest apartment in the loft above our barn. Last week, the building department red-tagged it because we don’t have a one-hour fire separation between the barn and the living unit. We know that firewalls are required in garages, but does this rule also apply to barns? — Davin

A : Fire-resistant walls and ceilings are required when a building has more than one type of occupancy. Examples of occupancy types are residences, offices, stores, factories, schools, etc. A single-family dwelling (listed as a Type R occupancy) is required to have a one-hour separation from a garage (a Type U occupancy). But Type U occupancies include agricultural buildings, as well. Therefore, your guest apartment should have a one-hour fire separation from the barn area.

There are vital reasons for this fire-safety requirement: Barns are commonly used for storage of combustible materials such as hay and straw. Besides being flammable, these organic materials are capable of spontaneous combustion because they can generate heat and methane gas if composting occurs.

If a barn were to catch fire beneath the exposed wooden floor of a dwelling unit, the occupants could become trapped within minutes. To provide adequate fire safety, a onehour fire separation between the barn and dwelling is essential. This includes protection of the barn ceiling, as well as support walls and posts. All of these surfaces should be finished with half-inch fire-rated drywall. Penetrations such as air ducts and access openings should consist of fire-rated materials, and any doorway providing egress between the barn and the dwelling unit should be fire-rated and selfclosing.

For additional fire-safety compliance, be sure to install smoke alarms in the apartment and barn. Additionally, the living unit should have windows large enough to comply with fire-escape requirements.