Wood Construction CTC-375

Wood Lumber Any wood cut into a size and shape used as a building material Timber – lumber with smallest dimension >5” Board - <2” thick, at least 2” wide Dimension - >2” thick, <5” thick, 2+” wide Beam & stringer - >5” thick, 8”+ wide Post & Beam – lumber approximately square 5+” thick and wide

Available in sizes from 8 – 16 feet Rough sawn lumber Sawn on all four sides to a nominal thickness and width Dressed lumber Sanded on 1 -4 sides Called by nominal size Sanding takes ¼” off per side Available in sizes from 8 – 16 feet Studs also available at 92” – gives 8’ ceiling height

Types of wood construction Post & Beam Wooden frame provides structural support No interior bearing walls Posts must be attached to foundation Balloon Framing F 13-4 Exterior walls are continuous from foundation to roof Floors are attached to the walls Revived in 1980’s as solar power gained popularity Need to place fire breaks in the walls

Platform Framing F 13-3 Walls rest on floors Floor is built to edge of foundation then sheathed Wall is built on top of floor Walls have single bottom plate and double top plate for strength Fire blocks at every floor

Panels or module construction Structural Insulated Panels (SIP) Can be walls or roof systems Conventional floor system but walls are constructed off site in 4x8 panels and hauled to site Allows for windows, doors to be installed at same time as walls Must have a flat surface

Construction Hurricane clips for roof Anchor bolts and tie downs for foundation-frame connections Blocking Where do you place blocking? Joist Bridging Makes floor into a system

Floor Systems Conventional 2x construction Engineered Lumber Box beam surrounds joists Girders are built up from 2x stock Joists are 2x stock 16” o.c. ¾” sheathing is glued and screwed onto joists Can use 5/8” sheathing but total floor must = 1.25” Engineered Lumber I-joists – 2x3 top & bottoms with OSB web Long and strong Can span 40 – 60 feet – eliminates interior bearing walls

Floor Trusses Holes in Joists Usually used in commercial buildings Provide long spans Holes in Joists Holes only in center of joist (neutral axis) and only within 1/3 of span of end Diameter not more than 1/3 of height or be closer than 2” from an edge

Roof Trusses Components F 13-12 Truss types F 13-13 Erection F 13-14 Bracing F 13-15

Timber Construction F 13-24 Post and beam on a larger scale Connections F 13-25