What is the maximum allowable exposure of lumber in sawn or glued laminated plank floors to walls in Type IV construction?

The maximum allowable exposure of lumber in sawn or glued laminated plank floors to walls in Type IV construction is specified to be a half inch. This requirement is established to ensure that there is adequate fire-resistance between the structural elements of the building and the surrounding walls. Type IV construction, also known as "heavy timber," has specific fire safety regulations due to the use of large wooden members, which could contribute to fire spread if not properly managed.

The purpose of limiting the exposure to a half inch is to minimize the risk of fire exposure to wall surfaces and to enhance the overall fire resistance of the structure. This approach helps maintain the integrity of wall elements during a fire event, slowing the spread of fire and allowing for safer evacuation and emergency response.

Understanding this limit is crucial for compliance with building codes and promoting fire safety in commercial buildings.