Type IV heavy timber. HEAVY TIMBER relates to fire resistance and is specifically defined as a construction type—Type IV—within the 2015 International Building Code (IBC). combustible materials 3. Buildings with mass timber and timber-frame systems can be used within the heavy timber category if the minimum sizes specified for Type IV construction are met. Free View-only Download (17 pages, 2.8 MB PDF) February 2004. If the loads were heavy when the building was constructed, expect to see framing members much larger than minimum. Wood members of heavy timber framing are commonly known as post, beam, jetty, truss and brace. Structural materials must meet minimum size requirements and be made of non. requires heavy timber framing with noncombustible (masonry, steel, or concrete) exterior walls . What size planks should I use ? Must be protected against decay b. What are the important factors in detailing the junction of a wood beam with a masonry loadbearing wall? Timber framing consists of joining heavy timbers together with pegged mortise and tenon joints, scarf joints or lap joints. Heavy timber construction is one of the oldest types of buildings used in the development of this country. Type IV classification is also a combustible building type, but it requires the use of minimum sized timbers which, due to their size, inherently provide protection from structural failure as the result of a fire. WCD 6 - Design of Wood Frame Structures for Permanence. Before we get into the lightness of heavy timber construction, let’s start by defining, “heavy timber,” both solid-sawn and engineered laminates. The answer is quite simple, the narrower the plank, the more supports you are going to have to supply. Not surprisingly, the primary difference between “light” and “heavy timber” is the section size of the construction members. Its superior performance has been demonstrated in thousands of buildings during the past … 1.3 Timber strength class C16 (cost-effective, for most applications) C24 (stronger, more demanding) WCD 5 - Heavy Timber Construction. a. What are the two basic requirements for Type IV Heavy Timber construction in the International Building Code? a. Type IV Heavy Timber Construction. Heavy timbers are a type of lumber that is differentiated from dimensional lumber by having minimum dimensions of 5 inches. When masonry or concrete material is used in the exterior wall assembly, heavy timber construction is classified as Type IV - Heavy Timber. We would aim to use a 150x47 joist and support this at a minimum of every 2.0m Sometimes this isn't practical and a narrower joist may be required, perhaps a 100x47 - not a problem, just place the supports no wider than 1.5m apart. WCD 5 - Heavy Timber Construction.