Heavy Timber Materials and Methods

What is Heavy Timber Type 4 Construction Heavy timber also referred to as Mill construction or slow burning construction Minimum sizes for timbers and decking of heavy timber construction are specified in another section of the code, these requirement are summarized to the right.

Why use Heavy Timber Fire Resistance Large timbers absorb a lot of heat Slower to catch fire and burn Will continue to support loads long after unprotected steel beams would.

Heavy Timber Shrinkage Because of size shrinkage is a major factor Cross grain wood is eliminated Today we use more laminated wood to eliminate shrinkage

Anchoring Beams to Masonry Walls Space kept between bean and wall to eliminate moisture Cut at angle in case

Floor and roof decks for heavy timber Code requires that heavy timber buildings have floors and roofs of solid wood construction without internal cavities These poses problems with mechanical systems

Combustible Buildings framed with heavy timber Heavy timbers are often used in combination with smaller wood framing members to construct buildings that do not meet all the fire-resistive requirements for heavy timber construction. These buildings are classified as type 5 This type of construction brings the appearance and structural performance of beam and decking framing to small freestanding buildings

Heavy Timber Spans Are typically less than 20ft unless laminated

Heavy Timber Arcs Originally cut from bent trees Today laminated to shape

Heavy Timber Trusses Span distances of over 100ft Rather then toothed plates joints are made with steel bolts and welded steel plates connections.