Construction Materials part I

Construction Materials part I

Wood is divided into two main classes

• Softwood-conifers (needles, cones)

• Hardwood-broadleaved deciduous (loose their leaves)

Multiple Choice

Does a pinecone come from a softwood tree or a hardwood tree?

• Softwood

• Hardwood

Softwood Lumber

• Made from conifer trees (needles, cones)

• Fir, pine, redwood trees

• Excellent structural properties

• used for rough framing members

• A cheaper wood

• Doesn't have as desirable of a finish

Hardwood

• Broadleaved deciduous trees (lose leaves in the Fall)

• Maple, Oak, Birch

• Hard, durable, wear-resistant

• Used for finish applications

• Used for furniture

• More expensive

• Has a desirable grain

Multiple Choice

True or False-Softwoods are used for structural framing.

• True

• False

Multiple Choice

Will birch be used to frame a house or as a finish material?

• Framing

• Finishing

Rough Lumber

• Structural members (softwoods)

• Described by its nominal size such as 2x4, 2x6, 1x6

• Nominal sizes are not actual sizes, but are used for descriptive purposes

• Example: 2x4=1.5x3.5

• Engineered wood products can take place of solid wood members for an even greater structural capability

Multiple Choice

True or False-A 2x4 is 2"x4"

• True

• False

Symbols

The symbol for end views of wood members is diagonal lines drawn through the member.

Face views of framing members are shown with two parallel lines.

Finish wood members are shown with freehand lines to represent the wood grain.

Multiple Choice

When symbols are used to represent wood members in a section view, two _________ lines indicate end views of framing members.

• horizontal

• vertical

• diagonal

Trim Members

• Come in many types, shapes and sizes

• Are available unfinished, primed or prefinished

• Softwood molding is typically primed to be painted

• Hardwoods are unfinished or prefinished to show the natural finish

Multiple Choice

Moldings are a type of ______ member.

• Finish

• Framing

• Roughing

• Coping

Plywood

• Panel product made in plies (wood layers)

• glued and pressed together under intense heat and pressure

• Comes in different different number of plies-always in an odd number. (3,5,7,9)

• Come in different grades depending on their intended use.

• Comes in different sized sheets

• Not to be confused with OSB

Oriented Strand Board (OSB)

• wood panel in which strands are mechanically oriented in particular directions and bonded with resin under heat and pressure.

• used as roof sheathing, subfloor sheathing, wall sheathing

• used as the web in an I-Joist (floor joist, ceiling joist)

• cheaper than plywood