. Discuss the changes in moisture content and the effects of these changes on a piece of dimension lumber from the time the tree is cut, through its processing, and until it had been in service in a building for an entire year?

Faces of edge grain boards have tighter and pleasing grain figures and they tend to remain flat despite the changes in moisture content. Edge grain lumber also holds paint better than plain swan timber in some wood pieces. Edge grain end up being expensive (hardwoods and finish flooring)

Free water, bound water (cell walls), lumber shrinks. 13% to 19% is considered seasoned. Wood will continue to lose water and then gain water depending on humidity.

What is the difference between Plain Sawn and Quartersawn lumber? What applications are appropriate for each?

Plain Sawing

               Plain sawing is the method of dividing the log into max number of useful pieces. As large number pieces can be produced, plain swing is highly economical. Cut horizontal and vertical. Produced faster, more affordable, varied grain, readily available,

Quarter Sawing

               Quartersawn wood is a method of cutting a log lengthwise into quarters, then creating a series of parallel cuts, with the middle cut being perpendicular to the tree’s rings. Quarter sawn wood has the straight grain and is much more expensive due to the greater amount of waste that is generated in the milling process. Cut diagonally. More stable, resists shrinking, reduces twisting, warping and splitting, wears away less, better for painting.

Give the actual cross-sectional dimensions of the following pieces of kiln-dried lumber. 1x4, 2x4, 2x6, 2x8, 4x4, 4x12.

1x4 = .75x3.5  

2x4 = 1.5x3.5

2x6 = 1.5x5.5

2x8  = 1.5x7.25 

4x4 = 3.5x3.5

4x12 = 3.5x11.25

Why is wood laminated? What types of wood products make use of laminations?

Wood is laminated to achieve a size, shape, or quality of piece that would otherwise be impossible.

               Glue laminated Wood – large structures by joining many smaller strips with glue

Structural composite Lumber – products are substitutes for solid lumber made from wood veneers or wood fiber strands and glue

Wood plastic composite (WPC) decking and nonstructural lumber – WPC made from wood fibers and plastics

What are the advantages of using of structural composite lumber (SCL) in comparison to solid wood?

SCL – wide variety of thickness, sizes, grades, and exposure, stability and structural strength, can be cut, drilled routed, jointed, glued, and fastened. Can be finished easily with paints, stains, and varnishes.

What is meant by a span rating of 32/16? What types of wood products are rated this way?

Span rating system is to permit the use of different woods. 32 is the allowable span in inches between centers of rafters when used roof sheathing. 16 is the allowable span when used as subflooring. Panel will be placed perpendicular to the length.

Name the most appropriate plywood veneer grade for each of the following applications: a) the outer face of the wall or roof sheathing panel, b) subflooring to receive a wood finish flooring, c) underlayment to receive a thin, resilient vinyl floor covering, d) plywood to receive a paint finish in an application demanding the highest possible finish quality.

For what reasons might you specify preservative-treated wood? What alternative materials may be used where preservative treated wood is normally required?

Preservative-Treated wood is used where decay/insect resistance is required. Marine docks, fences, and docks. To replace lumber treated with salts that do not contain arsenic is used.

Which common species of wood have naturally decay- and insect- resistant heartwood?

Redwood, cedar, black locust, and black walnut – decay resistant

        Redwood and eastern red cedar – insects resistant

Why are nails the fasteners of choice in wood construction?

Fasteners is the weakest point, nails are inexpensive and versatile, no advance drilling, quickly driven into wood.