What is a Class B interior finish?

Interior finishes are broken down into three classifications: • Class A Interior Wall and Ceiling Finish (flame spread index 0-25, smoke developed index 0-450) • Class B Interior Wall and Ceiling Finish (flame spread index 26-75, smoke developed index 0-450)

What is a Class A wall finish?

Class A is the strictest and includes any material classed at a flame-spread rating of less than 25 with a smoke-developed rating below 450. Class B includes materials with flame-spread ratings between 25 and 75, and smoke test ratings below 450.

What are Class A finishes?

“Class A” finishes generally have the fewest surface defects and most consistent color and gloss. A good example would be a refrigerator door or an automobile hood. In essence, a “Class A” finish would be applied to those parts of a product first seen by a prospective buyer.

What is a Class 2 floor finish?

The building and fire codes establish floor finish “classes” based on the materials’ ignition resistance. Class I indicates a higher amount of heat is required (0.45 watts per square centimeter (W/cm2)) to ignite the test sample. Class II indicates a lower amount of heat is required (0.22W/cm2).

What are Class C finishes?

Class C interior finish materials shall be permitted in places of assembly with an occupant load of 300 persons or less. For places of religious worship, wood used for ornamental purposes, trusses, paneling or chancel furnishing shall be permitted. Class B material is required where the building exceeds two stories.

Is plywood a Class C finish?

Untreated or unpainted (intumescent paint) plywood is considered a Class C finish. For sprinkled Health Care facilities, Section 10.2. 8.1 allows Class C in any location where Class B is required as described above, or Class B in any location where Class B is required as described above.

Can Class C finishes be used in an exit corridor?

Class C interior finish materials shall be permitted in rooms with a capacity of four persons or less. j. Class B materials shall be permitted as wainscotting extending not more than 48 inches above the finished floor in exit access corridors.

What is a Class B material?

In fire classes, a Class B fire is a fire in flammable liquids or flammable gases, petroleum greases, tars, oils, oil-based paints, solvents, lacquers, or alcohols. For example, propane, natural gas, gasoline and kerosene fires are types of Class B fires.

What is class A plywood?

Class A Fire-Rated Plywood Class A is the most desirable category for fire-rated plywood as it indicates a flame spread index of 25 or less. For fire-retardant wood to be substituted for a noncombustible material, it is required to have a Class A rating.

What is the difference between Class 1 and Class 2 concrete?

Class 1 finish – only reserved for restricted uses. Class 2 is that which will be specified for most good quality architectural precast concrete. A Class 2 finish is intended for external and internal façades that can be viewed in detail.