Heavy Timber

1. Heavy Timber Materials and Methods

2. 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.

3. 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.

4. 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

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

6. 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

7. 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

8. Heavy Timber Spans • Are typically less than 20ft unless laminated

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

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