Timber, also known as wood, can be used for many structural and engineering purposes. Some key points covered in the document include: - Timber has advantages such as availability, salvage value, ease of transport and joining. - It has many uses including for railway sleepers, roof trusses, furniture, formwork, and packaging. - Timber comes in various market forms depending on its size, including battens, logs, planks, boards, and poles. - Veneers are thin wood sheets used to make plywood, which layers veneers with perpendicular grain directions to increase strength. - Different types of timber have varying properties making some more suitable for uses like construction

1. TIMBER

2. CONTENTS…
 Introduction
 Advantages
 Uses of timber
 Market forms of timber
 Veneers
 Plywood

3. INTRODUCTI
ON

4.  Timber is another name for wood, whether still
standing in the form of trees or felled and turned
into boards for construction.
 Timber is very common for engineering
purposes as it is considered as an important
structural material.
 There is a difference between wood and timber.
Wood includes all types of wood which maybe
burning wood, structural wood, furniture wood
etc. But wood suitable for use as a structural
material is called Timber.

5. ADVANTAGES
 It is easily available every where.
 Its salvage value is high.
 It can be easily transported by converting
large pieces into smaller pieces.
 It can be easily joined.
 Being light in weight it is preferred for
building works in earthquake prone areas.

6. USES OF TIMBER
 It is very much used for railway track
sleepers.
 It can be used as members of roofing
trusses.
 It is an important material for furniture
making.
 It is used as form work for cement concrete
structures.
 Packing cases are mostly made from soft
timber.
 It is used for floors, ceiling ,partition walls.

7. Timber used as frame work Timber used for making furnitures.
For packaging Timber is used for railway sleepers

8. DEFECTS IN TIMBER…
The defects that usually occur in the timber
may be classified into two categories:
 Defects that develop during growth of the
tree.
 Defects that develop after felling the tree.

9. SOME OF THE DEFECTS THAT DEVELOP DURING
GROWTH OF THE TREE…

10. SOME OF THE DEFECTS THAT DEVELOP AFTER
FELLING THE TREES…
SPLIT

11. PRESERVATION OF TIMBER…
The methods that are commonly used for the
preservation of timber are:
1.charring
2.tarring
3.painting
4.creosoting
5.wolman’s salt
6.ascu-treatment
7.vaccum-pressure process
8.hot and cold process
9.seasoning of the timber.

12. QUALITIES OF GOOD TIMBER
Following are the qualities of good timber-
 A good timber should be hard and durable.
 It should be capable of resisting the actions of fungi,
chemicals and physical agencies.
 The fibers of the timber should be straight and compact.
 Its freshly cut surface should smell sweet.
 Its weight should be heavy.
 Timber should be tough i.e. should be capable of resisting
shocks.
 It should be able to withstand the weathering effects.
 A clear ringing sound should be emitted by the timber
when struck. Heavy dull sound indicates decayed timber.
 It should offer adequate fire resistance and should be
elastic.

13. MARKET FORMS OF TIMBER
 Battens: these are small sectioned timber
pieces. No cross sectional dimension exceeds 5
cm in battens.
 Logs: trunk of trees left after removing all the
branches is known as log.
 Baulk: it is roughly squared swan log .one of the
cross sectional dimensions exceeds 5 cm while
the other exceeds 20 cm.
 Planks: it is a timber piece with parallel sides. Its
thickness is always less than 5 cm and width
always more than 5 cm.

14.  Board: it is a timber piece with parallel sides
whose thickness is always less than 5cm and
width always more than 15cm.
 Deal: it is again a parallel sided piece whose
thickness varies from 5cm to 10cm and width
does not exceed 23cm.
 Scantlings: these are timber pieces whose
breadth and thickness are always more than
5cm but their length is always than 20 cm.
 Pole: it is a log having its diameter not more
than 20cm. It is also known as spar.

15. VENEERS

16.  Veneers are thin sheets of timber of very superior
quality. they are obtained by rotating wooden logs of
very high quality timber against a sharp knife of rotary
cutter.
 Thickness of veneer may vary from 0.4mm to as
much as 6mm or even more.
 It is peeled off from timbers like teak, rosewood, oak,
mahogany etc.
 The process of preparing a sheet of veneers is known
as veneering. It may also include gluing of veneer
sheets of superior quality over a base of wood of
inferior quality.

17. PLYWOOD

18.  Ply means thin layer. Plywood is in form of boards
prepared from thin layers of wood or veneers.
 Veneers in plywood are taken in odd numbers and
are then placed one above the other with the
direction of grains of successive layers at right angles
to each other.
 All veneers are held together by adhesives. The
direction of grains at right angles in successive
veneers increase the strength of the plywood.
 The face of the plywood with better finishing is known
as face and other exposed face as back of the
plywood.
 Plywood sheets are manufactured in size varying
from 90cm*90cm to 240*120cm.

19. ADVANTAGES…
 They suffer little expansion or shrinkage due
to variation in moisture content.
 They are light and are available in large
sizes.
 They are available in decorative designs.
 They are not liable to split or crack.
 They make use of costly timbers in most
economical manner.
 They re easy to work with.

20. DIFFERENCE B/W VENER AND PLYWOOD
 Plywood is a type of manufactured wood panel.
It is made by gluing together plywood layers,
also called veneers. These veneers are glued
together with adjacent plies having their wood
grain at right angles to each other. Veneer, on
the other hand, refers to thin slices of wood that
are practically peeled of the wood. The slices
are usually less than 3 mm (1/8 inch) thick.


21. FIBER
BOARDS

22.  Fiber boards are manufactured from wood or
other vegetable fiber.
 The pieces of wood, cane, or other vegetable
fibers are heated in a hot water boiler. Due to
boiling wood fibers get separated.
 These fibers are put in a vessel and steam is
admitted in it under pressure. The steam
pressure is then suddenly increased which is
then maintained for few seconds.
 In doing so the natural adhesive contained in
fibers is separated completely.

23.  The fibers are then taken out of vessel and
cleaned of all superfluous gums. the fibers
also obtained are spread on wire screen I
forum of loose sheets and pressed.
 The resulting material is called the fiber
board.
 These are rigid boards of thickness varying
from 6mm to as much as 25mm. Their width
is 1.2m and length 3.5m.
 They are also known as presses wood or
reconstructed wood.


24.  Depending upon their form and composition
fiber boards are classified as insulating boards,
medium hard boards, super hard boards, hard
boards and laminated boards.
 Uses:
1. For the construction of wall panels and
suspended ceilings.
2. To construct partitions.
3. As insulting material against heat and sound.
4. As table tops and for flush doors.

25. HARDWOOD AND SOFT WOOD
 Hardwood contrasts with softwoods
Hardwoods are not necessarily harder than
softwoods. In both groups there is an
enormous variation in actual wood hardness,
with the range in density in hardwoods
completely including that of softwoods; some
hardwoods (e.g., balsa) are softer than most
softwoods, while yew is an example of a
hard softwood.

26. IMPREG
TIMBER

27.  Laminates, formica, sungloss etc are the
examples of impreg timber.
 Impreg timber is nothing but timber fully or
partly covered with resin.
 Impreg timbers are strong, durable, good
looking and are not affected by moisture and
weather conditions.
 They resist acidic effects and are electrically
insulated.

28. PROPERTIES OF SOME
IMPORTANT TIMBER

29. BABUL
 Its timber is strong, hard and tough.
 It is durable but difficult to work.
 Its texture is quite strong.
 It is not available in large lengths.
 Its color is whitish red which turns to red brown due to exposure.
 It is used for the construction of bullock carts, tool handles, well curbs and
agricultural implements etc.
Bullock cart
Logs of babul tree
Wooden handle

30. DEODAR
 It is compact, hard, durable and strong.
 It is yellow in color.
 It is easy to work with.
 Receives varnish very easily.
 It is used for railway sleepers, piles and other
construction work, cheap furniture and
railway carriages.

31. SAL
 Its color is either light brown or yellow.
 It is hard, compact and heavy.
 It is durable and strong.
 It cannot be finely polished.
 Its seasoning is very slow.
 It cannot be used for decorative purpose
because its surface cannot be finely finished.
 It is mostly used for tent pegs, doors and
window frames etc.

32. TEAK
 It is used for ship building, railway sleepers,
furniture, railway carriages.
 It can be used for any structural or decorative
purpose.
 It is a costly timber and hence used for costly
and specialized work.
 It can be easily seasoned and is easy to work
with.
 It does not wrap due to shrinkage and is fire
resistant, acidic action resistant and also white
ant resistant.

33. SHISHAM
 It is used for furniture, ply wood, sports
goods, railway sleepers etc.
 It is dark brown in color with golden and dark
brown colored lining.
 It can be easily seasoned and receives high
class polish.
 It is difficult to work with.

34.  Aini : it is yellowish brown and can be used under
water. It takes fine polish.
 Arjun: it is dark brown and is heavy timber.used for
rafters, beams etc
 Bamboo: used for scaffolding, thatch roofs etc.
 Mahogany: used for furniture, pattern making, cabinet
work etc. it is reddish brown in colour. It contains
resinous oil to save itself from insect attack.
 Mulberry: it is tough, elastic and strong. It takes clean
finish and is used for baskets, hockey sticks, sports
and furniture.

35. CAMBIUM LAYER
 The bark on the
outside of the tree
protects the Living
cambium layer that lies
just underneath. It is
the cambium layer that
produces the growth
rings inside the tree,
adding new layers of
phloem and xylem
each season .

36. DIFFERENCE B/W M.D.F AND H.D.F
MDF HDF
 MDF is a product of soft
woods that are broken
down by a defibrator,
added to wax and resin,
and formed from heat and
pressure.
 MDF is sensitive to
moisture.
 HDF is also a product of
soft woods that are broken
down by a defibrator,
added to wax and resin and
formed from heat and
pressure. But it is much
more dense and made from
exploded wood fibres.
 HDF is highly resistant to
mold and infestation and is
not sensitive to moisture.

37. ENDOGENOUS AND EXOGENOUS
 Exogenous trees grow in width by forming a
new layer of wood under the bark.
 Endogenous trees grow by forming new
fibres within the trunk interspersed with the
old fibres.

38. BIBLIOGRAPHY
 Building materials by Gurucharan Singh.
 www.google.com
 www.slideshare.net

39. THANK YOU