1. WOOD
TIMBER
DIFFERENCE BETWEEN
WOOD AND TIMBER
TIMBER IN DETAIL
INDUSTRIAL TIMBER
FORMS OF TIMBER
DEFECTS ON TIMBER
PRESERVATIVE
METHODS OF TIMBER
INTRODUCTIONS OF
VARIOUS TYPES OF
WOOD AND TIMBER
AND THEIR USES
2. Wood is a hand fibrous material that forms the
main substances of the trunk or branches of a tree.
It is cut and used on timber or for fuel purpose. It
is solid material derived from woody plants , not
only trees but also shrubs. It is a heterogeneous,
hygroscope and cellular material.
Oak, Maple, Mahogany, Cherry, Walnut,
Rosewood, Teak, etc. are known as HARDWOOD.
Pine, Ash, Hickory, Beech, Birch, Cedar, Fir,
Spruce.etc. are ex. Of SOFTWOOD.
3. It is a wood material which is manufactured into boards. It is used
for building, carpentry and various construction or structural
purposes. It can be rough or finished.
As a rough, it is the raw material for furniture making and other
items required additional cutting and shaping. As a finished it is
available in drill sizes or construction industry and for high grade
flooring.
Timber plant species are found in 150 species which are produced
in INDIA.
Tea, Sal, Sandalwood, Sea sum Babul, Banyan, Coconut, Deodar
etc, are some ex. Of Timber.
Timber is available in different forms.–
1. Converted timber , which is sawn and cut into suitable
commercial sizes.
2. Rough timber which is obtained after falling a tree.
3. Standing timber which is available in a living tree.
4. Wood includes all types of wood which may be
burning wood , structural wood, furniture wood
etc. but when wood suitable for use as a structural
material is called Timber.
Wood is commonly found in the stems and roots of
the trees. It is natural composite of cello use fibers.
Timber is used to refer to any stage of the wood
after the tree has been cut down. This may include
the felled tree, wood processed for construction ,
wood pulp for paper production etc. Timber is also
known as LUMBER.
5. PROPERTIES OF TIMBER
Timber with heavy weight is considered best quality.
It should be hard uniform and compact.
It should have dark color, straight fibers, and shinning appearance
and should be free from defects and good sound should emit
when struck.
SEASONING OF TIMBER
This is the process of drying of timber in order to remove all the
plant juice and moisture out of it so that it will not decay.
Seasoning of timber may be done naturally or artificially.
PRESERVATION OF TIMBER
It is the process which protect the timber from moisture, fungi,
insects and direct weathering effects to ensure its increased life.
Oil paints, coal tar, chemical salts etc are some preservatives are
used.
7. Timber which is scientifically prepared in factory to get the
desired shape, size, appearance, and strength is known as
INDUSTRIAL TIMBER. It is available in various variety such as
Plywood, Veneer, Laminated timber, block board, fiber boards etc.
Veneers are thin sheets or slices of wood of superior quality
which are knife cut by various processes. It is used to produce
plywood, batten boards and laminated boards and this process is
called veneering. Thickness – varies from 4mm to as much as
6mm or even more.
Plywood is prepared by cementing together thin boards or sheets
or wood into panels. Three or more veneers which are always odd
in numbers are placed one above the other so that the grain of
each layer is at right angles to the grain in the adjacent layer. It is
used for interior partition , doors and paneling. It is generally
manufactured in 3 ply, 5 ply , 7 ply and so on. Thickness - varies
from 3mm to 5mm.
8. Fiber board is rigid board which is prepared after
processing pieces of wood, cane and then pressing them
together that’s why it ia also called pressed wood or
reconstructed wood.. It is available in various forms like
laminated boards, hard boards etc. It is used for wall
paneling, suspending ceiling and partitions, table tops, for
flush doors etc. thickness- varies from 6mm to as much as
25mm.
Block board has a core made up of strips of wood glued or
joined to form a slab which is further glued between two or
more outer veneers in such a way that direction of the grain
of the core blocks running at right angles to the adjacent
outer veneers. These are of two types: commercial and
decorative. It is used for furniture, paneling, partition.
Thickness are 12mm to 50mm length vary from 1.2mm
to2.4mm and width from 90cm to 1.2m.
9. Hard board are manufactured from wood wastes
obtained from saw mills, inferior timber or short logs.
Raw material is converted into chips with the help of
machines which are softened with steam and
converted into fibers. The maximum length is 4.75m
and thickness varies from 2mm to 20mm. It is used for
interior or exterior wall panels, ceiling, siding, table
and counter tops etc. It is free from defects like shakes
and knots.
Batten boards are just like laminate boards and block
boards are made from timber blocks of width of 8cm
and 2to 3cm thick. Direction of the grains of core batten
is at right angles to that of adjacent out ply sheet. There
are used for door panels, table top and other large
surfaces.
10. BATTENS are small sectioned timber pieces.
LOGS : Trunks of trees left after removing all the branches
is called log.
BAULK is roughly squared swan log.
PLANKS are timber pieces having parallel sides with less
than 5cm thickness and width always more than 5cm.
BOARD is also timber piece with parallel sides with less
than 5cm thickness and more than 15cm width.
DEAL is also parallel sided piece , thickness varies from
5cm to10cm and width should not exceed 23cm.
SCANTLINGS are timber pieces , thickness and breath is
always more than 5cm and length is not less than 20cm.
POLE OR SPAR is a log having 20cm diameter.
11. A good timber should be hard ,tough,
durable, heavy, straight and compact fibers,
properly seasoned, elastic, dark and uniform
color, sweet smell and freshly surface and
adquate fire resistance.
It should be capable of resisting the action of
fungi, chemicals and physical agencies and free
from knots, twists, upsets, burls, shakes etc.
A clear ringing sound should be emitted by
the timber when struck.
13. SHAKES : Cracks which partly or completely separate the fibers of wood. Shakes
are many types- star shakes, heart shakes, cup shakes, ring shakes, radial shakes.
RIND GALLS : Curved swelling on the body of the tree.
TWISTED FIBRES: Twisting of young trees constantly in one direction under the
action of strong prevalent winds.
UPSETS OR RUPTURES : This defect changes in direction of wooden fibers due
to felling of tree or fast blowing wind.
KNOTS: These are found at the bases of branches cut off from the tree. They may
be dead, live loose or tight. It is very difficult to plane timber at knots.
WIND CRACKS: Cracks on the outer surface of the tree due to atmospheric
agencies.
BURLS: Irregular projections appears on the surface of the tree
CALLUS: Soft tissue or skin which covers the wounds of the tree is called callus.
COARSE GRAIN: Timber having widened annual rings.
DEAD WOOD : It is indicated by its reddish color and light weight.
DRUXINESS: White decayed spots of timber remain concealed under healthy
wood due ti access of fungi.
FOXINESS: This defect is indicating by red or yellow tinge in wood.
14. BOW : Bow means when planks of converted timber shrink and
bend in curved form in the direction of length.
CUP : When wooden planks bend in curved form in transverse
direction.
TWIST: Distorted spirally wooden plank along its length.
CASE HARDENING: Upper surface of timber dries very fast and
shrinks.
HONEY COMBING DEFECTS: Various radial as well as circular
cracks develop in internal portion of the timber due to stresses
developed during drying.
RADIAL SHAKES: Radial cracks on the surface of timber
CHECK: A crack separating wood fibers.
SPLIT: When check extends from one end to other.
WANE: Original or natural rounded surface on timber.
DIAGNOL GRAINS: When timber is improperly sawn then
diagonal marks develops on straight grained surface of timber.
16. Coal tar, Oil paints , certain chemicals and Ascu treatments are
generally used to protect timber.
CHARRING : The timber is charred to be firstly kept wet one
hours and then burnt to a depth of about 15mm and cooled with
water, It is called charring. This protects timber from moisture,
fungi, or white aunts.
TARRING: In this method a later of hot tar is applied on the
surface of timber.
Paint : it is applied to timber not only makes it beautiful look but
also acts as a preservative.
WOLMAN’S SALTS : It is a Mixture of creosote oil and sodium
fluoride. It protects timber from fungi.
ASCU TREATMENT: It is prepared by mixing six parts of
Hydrated arsenic pent oxide, Copper sulphate and Potassium
Dichromate with 100 parts of water. It gives protection from
white aunts.
17. VACCUM PRESSURE PROCESS: It is considered one of
the best method which is two types
1. Bethel or full cell process– In this process air and moisture
get removed from the timber cells.
2. Rue ping or Empty cell process
HOT AND COLD PROCESS: In this process timber is
stacked in the tank and cold preservative solution till timber
stacks get completely submerged , then heated to a
temperature of about 90 degree C and maintained this
temperature for some times.
SEASONING OF TIMBER : Proper damp proofing and
providing free circulation of air around the built in portion
of timber are essential for preservation of timber used . If
timber is not properly seasoned then no preservatives
protect th timber.
18. OAK , a heavy strong
colored hard wood is
used to craft American
and English country
designs and mostly
used for sports good Its
color is yellowish
brown and possesses
straight silvery grains.
Its weights 865kg and
very strong and
durable.
19. MAPLE is so hard and
resistant to smocks that is
often used for bowling
alley floors. The bird eye
figure in maple is said to
be the result of stunted
growth and is quite rare.
It is used for American
colonial furniture,
especially in medium and
lower priced categories. It
can also be stained to
simulate cherry wood
which it resembles.
20. MAHOGANY is also known as
Honduras mahogany and much
ten valuable wood. Being ten
strong , not as durable not as
beautiful when finished
It has reddish brown color and
may display stripe ribbon ,
broken stripe, rope ripple,
mottle, fiddle back or bristle
figure.
It is used extensively in the
crafting of Georgian empire
and furniture , pattern making
cabinet work etc.
It contains resinous oil to save
itself from insects attack.
Weights 720kg after seasoning.
21. CHERRY is sometimes
called ‘ fruitwood’ and is
grown in the eastern half
of U.S.A. It has been called
New England Mahogany
and is often used to craft
18th century colonial and
French provincial designs.
A moderately hard,
strong, closed grain, light
to red brown wood,
cherry resists wrapping
and checking. It is easy to
card and polish and is
used in variety of styles.
22. WALNUT is one of the most
versatile and popular cabinet
making wood. It grows in
Europe, America and Asia. It
is strong , hard and durable
without being excessively
heavy. It has excellent word
working qualities and takes
finishes well. It is light to
dark , chocolate brown in
color with a straight grain in
the trunk.
It is used in all types of fine
cabinet work especially 18th
century reproductions.
23. ROSEWOOD is a
dark reddish brown
color hardwood
,fragrant and has
closed grains. It is not
easy to work and
takes high polish.
It is used in musical
instrument, piano
cases, tool handles, art
projects, veneers and
furniture.
24. TEAK is yellow to dark
brown hardwood which is
extremely heavy, strong
and durable. Its fibers are
straight , fir resistant,
acidic action resistant and
white ant resistant,.
It can be used for any
structural or decorative
work, such as ship
building, railway sleepers,
railway carriages and
furniture etc.
Its weights 770 kg.
25. BIRCH is hard, heavy
close grained
hardwood with a light
brown or reddish
colored heartwood
and cream or light
sapwood.
26. CEDAR is knotty
softwood which has
been a red brown color
with light streaks. It
aromatic and moth
repellent qualities have
made it a popular wood
for lining drawers,
boxes, simple cases and
storage closets are also
constructed from this
light brittle wood.
27. REDWOOD is rare,
valuable and best
quality of it comes from
the heartwood which is
resistant to
deterioration due to
sunlight, moisture and
insects.
It is used to craft
outdoor furniture and
decorative curving. Its
burls have ‘ a cluster of
eyes’ figure.
28. HEMLOCK is light in
weight , uniformly
texture has law
resistance to decay
and non resinous.
It is used for
construction lumber,
plants, door boards,
paneling, sub flooring
and craft works.
29. SPRUCE is strong ang
light in weight has
low resistance to
decay, moderate
shrinkage.
It is used for marts
and crates spares for
ships and aircrafts,
boxes, general
millworks, ladders
etc.
30. FIR is easy to work
and finishes well,
uniform in texture
and no resinous has
low resistance to
decay.
It is used in making
furniture, door and
window frames,
veneer, and interior
trim.
31. PINE is a soft white or
pale yrllow wood which is
light weight , straight
grain and lacks figure. It
decays easily when comes
in contact with soil. It is
used in the manufacturing
of matches.
While other colored pines
are quite hard and
tough.It is used for
pattern making, frames
for doors and windows,
paving materials etc.
There are more than 100
species of pine.
32. ASH is a heavy ring
porous wood has a
prominent grains that
resembles oak and
white to light brown
color. It burls have a
twisted interwoven
figure.
It is widely used for
structural frames and
steam bent furniture
pieces.
33. HICKORY is one of the
hardest and heaviest
softwood. Pecan is a
species of hickory some
times used in furniture.
It has close grains
without much figures. It
is used for structural
parts. Decorative
hickory veneers are also
commonly used.
34. BEECH has tiny pores
and large conspicuous
medullar rays and
similar in appearance to
maple, reddish brown
heartwood , light
sapwood and relatively
inexpensive.
It is often used for
frames, a variety of bent
and turned parts
quarter sliced and half
round cut beech veneers
are commonly used.
35. It is strong, hard, tough,
durable, quite strong
and difficult to work. Its
color is whitish red
which is turns brown
due to exposure and not
available in large
length. Weight is 880kg.
It is used for making the
wheels of bullock cart,
tool handles,
agricultural instruments
and well curbs.
36. CHIR is straight long
timber and have conical
leaves. Its color is
yellow becomes more
and more dark due to
exposure. Weight is
560kg and easy to work.
It is used for railway
sleepers, piles, railway
carriages, cheap
furniture etc.
37. BAKUL is reddish
brown in color and
used mostly for
making cabinets.
weight is 880kg.
38. BANYAN is a species
whose aerial roots are
utilized for tent polls,
well curbs etc.
It is strong and
durable only under
water . Its color is
brown and weight
580kg.
39. BAMBOO is used for
a scaffolding, thatch
roofs and temporary
bridges.
40. COCONUT is used as
poles, piles, furniture
and frame work in
concrete construction.
41. SAL is a very good
variety of timber and
can be used for any
purpose but not easy to
work. Its color is light
brown or yellow .
It is used for tent pegs,
doors and window
frames and as wooden
piles, bullies etc, but can
not used for decorative
works.
42. SHISHAM is also called
Tali or Sissue , one of
the most useful and
high class timber ,
heayy and can be
seasoned easily, Its
color is dark brown
containing golden and
dark brown colored
linings.
It is used for furniture's,
plywood, sports goods ,
railway sleepers,
bridges piles etc.
43. ARJUN is very strong
, heavy and durable
timber . Its color is
dark brown.
It is used in the form
of posts, beams ,
rafters etc.
44. LAUREL is a hard
tough type of timber
and likely to crack
and resist attack of
dry rot. Its color is
dark brown.
It is used for house
construction , boat
construction,
structural work and
railway sleepers.
45. MANGO is
moderately strong ,
easy to work and in
deep grey color.
It is used for making
cheap furniture,
packing boxes, panels
for doors and
windows etc.
46. TAMARIND is a fruit
giving tree, very
knotty and durable
timber and color is
dark brown.
It is used for well
curbs, sugar mills,
carts, brick burning.
Agricultural
implements.