Which type of construction is characterized by heavy timber and large spans between walls?

Type IV construction, also known as heavy timber construction, is characterized by its use of large timber beams and heavy timber framing. This method allows for large spans between walls, which is a distinct feature of this type. The substantial mass and thickness of the heavy timber members provide not only structural support but also contribute to fire resistance, as the larger wood members are less likely to ignite quickly than smaller dimensions.

This type of construction enables wide-open interior spaces, commonly utilized in commercial buildings, warehouses, and certain types of residential structures. The design facilitates flexibility in interior layouts, making it an attractive choice for many builders and architects.

The other construction types mentioned each have their own characteristics. For example, Type I construction is characterized by non-combustible materials, while Type II and Type III have varied uses of combustible and non-combustible materials but do not involve the heavy timber elements associated with Type IV. This distinction is crucial for understanding both building design and fire safety regulations.