Please take note of the required readings in the text book. Each exam will contain questions from the readings. Each exam will be ‘open book’, but not open note.

Materials Materials are a very powerful design element, and can lead a designer to develop forms, spaces, and emotional qualities in an interior environment. Selecting a material is like setting sail on a large body of water. Some of what will be designed is more a matter of ‘listening’ to what the material has to say, or in the words of Louis Kahn, famous American architect, ‘what the material wants to be.’

wood To design and build an interior wall out of wood, for example, will lead a designer into the vast and beautiful world of wood design. Think about all of the different uses of different types of wood that you have seen. From ornamental objects, to musical instruments, to construction grade subflooring, wood has many characteristics and many limitations.

Hardwoods & Softwoods: deciduous trees & non-deciduous trees: a red oak, and a douglas fir

wood comes from trees, and trees are divided into those that lose their leaves in the winter (deciduous) & those that do not (non-deciduous)

Hardwoods are deciduous trees that have broad leaves, product a fruit or nut, and generally go dormant in the winter. Many varieties of hardwood trees live in North America. Hardwood is generally expensive, and is used for finished surfaces, such as flooring, as for furniture. Softwoods are conifers, evergreen, and cone-bearing trees. Widely available in the U.S. softwoods include cedar, fir, hemlock, pine, redwood, and spruce. Softwoods are generally less expensive than hardwoods, and are primarily used as structural lumber, such as 2x4’s and 4 x 6’s, with limited decorative, or finish, applications.

the section through a log reveals the age of the tree and some of the climate character

the wood used to make these vases is ebony

maple, ash, birch, butternut, cherry, ebony, red oak, red cedar

walnut

pine logs & boards

hawaiian koa trees

hawaiian koa wood

wood is cut into regular shapes at sawmills

sawmills were often located on rivers, and logs were floated down the river to the sawmill.

Quartered and Rift Sawn Lumber What is quarter-sawn lumber? Technically, quarter-sawn lumber has the growth rings of the tree approximately perpendicular to the board's broad face. In contrast, plain-sawn lumber has the growth rings parallel to the board's broad face. Quarter-sawn produces both quartered and rift lumber How is quarter-sawn lumber achieved? There is only one true way to quarter saw a log. First, we cut a log into quarters. Each quarter is then processed by cutting a single board off of one face, then cutting the next board from the opposite face, and cutting from alternating faces until the quarter is completely cut

What are the structural qualities of quarter-sawn lumber? Quarter-sawn lumber is the uncontested winner when compared to plain- (or flat-) sawn lumber. Quarter-sawn features include: Reduces shrinking and swelling in lumber width. Reduces twisting, warping and cupping. Less prone to surface checking. Wears more evenly in flooring applications. Does not allow liquids to readily pass through it. Holds paint better. Smooth surface as raised grain is not pronounced. In short, qua rtered lumber provides greater dimensional stability in both seasoning and final use

There are two main methods of converting timber: Through and through (or Plain) and Q u arter also referred to as rift sawn. Quarter sawn is far more expensive because of the need to double (or more) handle the log and there is more wastage. It is however more decorative (principle cut for Arts & Crafts furniture) and less prone to cup or distort and will expand and contract less than boards sawn by other methods. Note also there are two ways of sawing the quarter. Plain produces mostly tangentially sawn timber and some quarter sawn material close to the center of the log creating the familiar “flame-shaped” or “cathedral” pattern. Tangential timber is prone to cupping but it is stronger when placed correctly. Because of this it is used extensively in the construction industry and especially for beams.

Quarter Sawn vs. Plain Sawn

A quarter sawn log

Quarter sawn board, on left Plain sawn board, on right

Maple flooring, left Oak flooring, right