Module 5 ( Woods) (copy)

Woods

1. Natural Warmth
2. Workability
3. Infinite Variety
4. Strength
5. Flexibility
6. Fire Protection
7. Color

Physical Properties of Wood

1. Sapwood
2. Heartwood
3. Pith

Classification of Woods

Sapwood

softer, younger outer portion of a tree that lies between the cambium and heartwood

Heart wood

older, harder, central portion of a tree, it contains deposits that give darker color than sapwood.

Pith

unstable, often completely void, or full of cheeks and cracks, and should be avoided when wood working. Also known for possibly expanding and contracting along its length.

1. Hardness
2. Flexibility
3. Strength
4. Durability

Properties of Wood

Hardness

measured by compression

Flexibility

the amount of piece will bend before breaking

1. Decay
2. Cheeks
3. Shakes
4. Knots
5. Warping

Defects of Wood

Decay

caused by attack of fungi

Cheeks

cracks or lengthwise separation across the rings caused by irregular shrinkage.

Shakes

cracks between and parallel to the rings.

Knots

Irregular growth in the body of a tree interrupt the smooth curve of the grain.

Warping

any variation with the plane surface caused by unequal shrinkage of the board.

1. Crook
2. Bow
3. Cup
4. Twist

Forms of Warp

Crook

a distortion of the board in which long edge is convex or concave

Cup

It is a distortion of the board in which the face is convex or concave across the board.

Bow

It is a distortion of the board in which the face is convex or concave longitudinal

Twist

it is a distortion of the board in which one corner is raised.

Log

cut tree

Lumber

cut to specified dimension

Timber

tree

1. Plain Sawing
2. Quarter Sawing
3. Lumber cut tangents to the rings

Method of Sawing

Lumber (tabla)

wood that is used in construction

1. Strips
2. Board Lumber
3. Dimension Lumber
4. Timbers

Four classification of Lumber

Strips

lumber less than 2'' thick and less than 8'' wide

Board Lumber

pieces less than 2'' and less than 5'' in any dimension.

Dimension Lumber

pieces more than 2'' and less than 5'' in any dimension.

Timbers

pieces 5'' or more on the smallest dimension

Nominal Size

the size of lumber when it is cut from the log.

Wood composites

are those products made from a mixture of wood an other materials?

Plywood

most common wood composites

Standard sizes of Plywood

3' x 6' (900mm to 1800 mm ) and 4' x 8' (1220 mm x 2440 mm)

1. 4.5 mm for double wall partitions and ceiling
2. 6mm for double wall partitions
3. 10mm and 12mm for drawers and shelves.

Standard thickness

- the approximate equalization of strength properties along its length and width
- greater resistance for checking and splitting
- less change in dimension due to moisture content

Advantage of Plywood

1. Ordinary Plywood
2. Form Plywood
3. Marine Plywood

Types of Plywood

Hardwood

made from wood fiber extracted from chips and pulped wood waste

1. Standard HB
2. Panel HB
3. Temp

Types of Hardboard

Chipboard

made by bonding together wood particles with an adhesive under heat and pressure to form a rigid board.

Medium Density Fiberboard

finishing materials made from vegetable fibers such as sugarcane stalks or corn pressed into sheets. It is not very strong but has a good property therefore it is usually used for ceiling only.

Gypsum Board / plaster board

- non combustible building board
- designed to use without addition of plaster for walls, ceilings or partitions.
- it is extensively used in "dry wall" construction

1. Square edge
2. Tapered edge

2 edge design

Square edge

cover strip jointing

tapered edge

jointed wall and ceiling

Practice board

made of smallwood chips and base materials, including cotton stalks, rice straw, baggase, conventional wood chips, and saw dust that have been pressed and glued together.

Millwork

consists of finished lumber which is further cut and processed at a lumber mill. Includes doors, windows, moldings, trim and other ornamental forms of wood.

paupo

mortar

la drillo

brick

kostura

mortar joints

senepa

plank board

bandeha

panel

palitada

plaster

rimatse

rivets