What type of construction is known for not allowing combustible concealed spaces?

Type IV construction, often referred to as heavy timber construction, is characterized by its use of large, solid wood members and is specifically designed to minimize the presence of combustible concealed spaces. This building method employs thick wooden beams and other structural components that are less susceptible to fire compared to smaller dimensional lumber or materials used in lighter construction types.

The absence of concealed spaces in Type IV construction helps to limit the potential for hidden fires, which can spread undetected in cavities and voids found in other construction types. By utilizing large, solid wood elements, this type not only provides substantial fire resistance but also inherently reduces the likelihood of fire spreading through concealed areas.

The other types of construction, such as Type I (non-combustible), Type II (limited combustible), and Type V (wood frame), can have concealed spaces that are more susceptible to fire transmission. Because of this design distinction, Type IV is recognized for its safety benefits in relation to fire hazards, making it the correct answer to the question about preventing combustible concealed spaces.