Chapter 1: Building Materials

How much should the “snow load” be in Cordova Alaska?

Why do we need to learn about the various types of building materials available for construction?

Objectives Describe the hardwood and softwood classifications. Define moisture content (M.C. and E.M.C.). Identify common defects in lumber. Define lumber grading terms. Calculate lumber sizes according to established industry standards. Explain plywood, hardboard, and particleboard grades and uses. Identify nail types and sizing units.

Objectives List precautions to observe while working with treated lumber. Identify types of engineered lumber and list their uses and advantages. Discuss the uses of metal structural materials and describe their advantages/disadvantages. Identify a variety of metal framing connectors and indicate where each is used.

Lumber Lumber is the Name given to Natural or Engineered Products of the Sawmill -Boards -Studs -Timbers -Post & Beams

Wood Structure

Kinds of Wood Softwoods – Conifers Hardwoods – Deciduous

Kinds of Wood Softwoods – Conifers Hardwoods – Deciduous

Cutting Lumber

Moisture Content (M.C.) MC = % of oven dry weight – Framing: 15% – Cabinet and Furniture: 7%-10%

Equilibrium MoistureContent (EMC) Molecules of water are constantly leaving and returning to the wood surface. If the same number of molecules of water return to as leave from the surface an equilibrium condition exists. Since the wood is neither gaining or losing water it is said to have reached an equilibrium moisture content, or EMC.

How is Lumber Dried? What process is best?

Lumber Defects

Lumber Softwood Grades: Boards (e.g., Finish – Prime), Dimension (Light Framing – Economy), & Timbers (No.1). See Fig 1.5 –Stress Values (MSR) Hardwood Grades: First and Seconds (FAS), Selects, No. 1 Common. Lumber Sizes: Nominal (2x4) and Dressed (1 ½ X 3 ½) Metric Lumber

Board Feet No. pcs. x T” x W” x L’ 2 Can you buy metric lumber? BD Ft. =

Square Feet How Much Extra Do You Add to Your Job?.

Panel Materials Plywood Composite Plywood Non-veneered Panels –Particle Board –Fiberboard –Oriented Strand Board

Why 15/32? Not ½”? Span Ratting: 32” for Roofs 16” for Subfloors

Hardwood & Plywood Grades Grading for Faces and Backs: No. 1, 2, or 3 G2S – Good two sides or (G1S) Lumber or Veneer Core

Particle Board Wood Flakes, Chips, and Shavings Bonded Together.

HardBoard Refined Wood Fibers Tempered One or two sides smooth

Oriented Strand Board (OSB) Flakes of Wood Bonded under heat and pressure. Many Applications

Wood Treatments Why Treat Wood? Pressure Treated Wood Three types of Liquid Preservatives –Waterborne (CCA, CZC, etc.) –Oilborne –Creosote

Engineered Lumber Engineered Structural Lumber is made up of Laminated Veneer Lumber (LVL), manufactured wood I-beams, and manufactured trusses. Using Engineered Structural Lumber products reduces demand on forests by using wood waste or small dimensional lumber in place of larger lumber.

Engineered Lumber Glulams …

Wood I-Beams

Open-Web Truss …

Nonwood Materials Metal Framing Members Gypsum and Metal Lath Wallboard and Sheathing Insulating Boards, baths, and loose insulation

Insulation

Strapping, Ties, & Hangers

Metal Fasteners Nails – 5 basic Types (penny – d) Many types of special nails (e.g., spiral) Nail Coatings: zinc, cement, resin Wood Screws

Concrete

Adhesive Bonding Agents Glues Adhesive Cements Mastics

THE END Building materials must be properly used – using “shoddy” construction practices is dangerous!