1. DEEPTASHREE SAHA
INTERIOR DESIGN
4th SEMESTER
CONSTRUCTION
MATERIALS
edexcel logo sourcewww.colossaltraining.co.uk
arch logo source : www.sholay.in

2. WOOD

3. What is construction material?
•Construction material is any material which is
used for construction purposes.
•Many naturally occurring substances have been
used to construct buildings :
oClay
oRocks
oSand
oWood
oTwigs
oLeaves
Clay
Stone
Sand
Twig

4. What is wood ?
•Wood is a porous and
fibrous structural tissue
found in the stems and
roots of trees and
other woody plants
• It has been used for
thousands of years for
both fuel and as a
construction material.
• It is an organic
material, a natural
composite of cellulose fi
bers (which are strong in
tension) embedded in
a matrix of lignin which
resists compression.

5. Classification of wood
WOOD
NATURAL
WOOD
ENGINEERED
WOOD

6. NATURAL WOOD

7. Where do we generally find
wood ?
fuel
flooring
furniture
fuel
utensils musical
instruments
sports equipments

8. Wood processing

9. Physical Properties
Wood rings Water content Colour
Grains Knots

10. Classification of natural
wood
NATURAL
WOOD
HARD
WOOD
SOFT
WOOD

11. Hard wood
•Hardwood is wood from dicot angios
perm trees
•The term may also be used for the
trees from which the wood is derived;
these are usually broad-leaved.
•In temperate and boreal latitudes th
ey are mostly deciduous, but
in tropics and subtropics mostly everg
reen
• Hardwoods are not necessarily
harder than softwoods

12. Hard wood
Characteristics
•Hardwoods have a more complex
structure than softwoods
•Dark in colour
•Expensive
•Slower growth rate
•Higher density
•Heavy in weight
•More fire resistant than soft wood
•Strong in compression and
tension

13. Hard wood
Examples - Oak
•Light in colour
•Heavy
•Ring porous
•Open grain
•Hard to work with.
•When treated it looks classy and
elegant

14. Hard wood
Examples - Oak products

15. Hard wood
Examples - Maple
• Maple is so hard and resistant to
shocks that it is often used for
bowling alley floors.
• Its diffuse evenly sized pores
give the wood a fine texture and
even grain.
•Maple that has a curly grain is
often used for violin backs.
•Burls, leaf figure, and birds-eye
figures found in maple are used
extensively for veneers.

16. Hard wood
Examples - Maple products

17. Hard wood
Examples - Mahogany
• An easy to work wood
•reddish brown in colour
•Expensive
•Strong
• poorly defined annual rings
•may display stripe, ribbon,
broken stripe, rope, ripple, mottle,
fiddle back or blister figures
•excellent carving wood and
finishes well

18. Hard wood
Examples - Mahogany products

19. Hard wood
Examples - Cherry
• hard
•Strong
•Light to red-brown wood
•Resists warping and checking
•Easy to carve and polish

20. Hard wood
Examples – Cherry products

21. Hard wood
Examples – Rubber wood
• light colour
•Medium density
•Usually from the tree of rubber
plantation
•Advertised as eco-friendly wood
oBecause It is not grown
specially for timber but instead
have timber as by product

22. Hard wood
Examples – Rubber wood products

23. Soft wood
•Softwood is wood from gymnosperm
trees such as conifers
• Softwood is the source of about 80%
of the world's production of timber
• Softwoods are not necessarily softer
than hardwoods
•The woods of long leaf pine, douglas
fir, and yew are much harder in the
mechanical sense than
several hardwoods

24. Soft wood
Characteristics
•Cheap comparative to hard wood
•Faster rate of growth
•Lower density
•Softer than hardwood
•Light in colour
•Light in weight
•Poor fire resistant
•Strength in tension but week in
sheer

25. Soft wood
Examples - Ash
•Hardwoods have a more complex
structure than softwoods
•Dark in colour
•Expensive
•Slower growth rate
•Higher density
•Heavy in weight
•More fire resistant than soft wood
•Strong in compression and
tension

26. Soft wood
Examples – Ash wood products

27. Soft wood
Examples - Pine
• soft
•White or pale yellow in colour
•Light weight
•Straight grains
•Lack figures
•Resists shrinking and swelling
•knotty

28. Soft wood
Examples – pine wood products

29. Soft wood
Examples -Cedar
• Knotty soft wood
•Red brown colour with light
steaks
•Aromatic and moth repellant
•Popular wood for lining drawers,
chests and boxes
• Brittle wood

30. Soft wood
Examples – cedar wood products

31. Soft wood
Examples –Red wood
• The best quality redwood comes
from the heartwood which is
resistant to deterioration due to
sunlight, moisture and insects
•Redwood burls have a "cluster of
eyes" figure.
•They are rare and valuable.

32. Soft wood
Examples – redwood products

33. NATURAL WOOD
seasoning

34. •Reduces moisture content of wood
•There are two main reasons :
i. Woodworking: when wood is used as a construction material,
whether as a structural support in a building or in wood
working objects, it will absorb or desorb moisture until it is in
equilibrium with its surroundings. Equilibration (usually drying)
causes unequal shrinkage in the wood, and can cause damage to
the wood if equilibration occurs too rapidly. The equilibration must
be controlled to prevent damage to the wood.
ii. Wood burning: when wood is burned, it is usually best to dry it first.

35. Over exploitation of natural
wood on nature
•Deforestation
•Desertification
•Extinction of species
•Forced migration
•Soil erosion
•Ozone depletion
•Greenhouse gas increase
•Natural hazard and desert
So
Need for
engineered wood
arises

36. ENGINEERED
WOOD

37. • Also called composite
wood, man-made wood,
or manufactured board
•Includes a range of
derivative wood products which
are manufactured by binding
or fixing the strands,
particles, fibers, or veneers or
boards of wood, together with
adhesives, or other methods of
fixation to form composite
materials
• Engineered wood products are
used in a variety of applications,
from home construction to
commercial buildings to
industrial products.

38. Engineered wood
Plywood
• Plywood is a sheet material manufactured
from thin layers or "plies" of wood
veneer that are glued together with adjacent
layers having their wood grain rotated up to
90 degrees to one another
•This alternation of the grain is called cross-
graining and has several important benefits:
o it reduces the tendency of wood to split
when nailed at the edges
o It reduces expansion and shrinkage,
providing improved dimensional stability
oIt makes the strength of the panel
consistent across all directions.

39. Engineered wood
Block board
• Blockboard is a wood based panel, made up
of a core of softwood strips glued together
• The strips may be up to about 28mm wide
and are placed edge to edge and sandwiched
between veneers of softwood, hardwood or
thin MDF or particleboard, glued under high
pressure
•The internal strips are generally made of light
weight poplar wood or spruce
•To achieve maximum strength, it is important
to ensure that the core runs lengthways
•has very good screw holding
•it has a good resistance to warping.

40. Engineered wood
Veneers
• veneer refers to thin slices of wood,
usually thinner than 3 mm (1/8 inch),
that typically are glued onto core
panels
•Veneer is obtained either by "peeling"
the trunk of a tree or by slicing large
rectangular blocks of wood known as
flitches
• The appearance of
the grain and figure in wood comes
from slicing through the growth rings of
a tree and depends upon the angle at
which the wood is sliced

41. Engineered wood
Laminates
• Lamination is the technique of
manufacturing a material in multiple layers, so
that the composite material achieves
improved strength, stability, sound insulation,
appearance or other properties from the use
of differing materials
•A laminate is usually permanently assembled
by heat, pressure, welding, or adhesives

42. • also known as chipboard
•manufactured
from wood chips, sawmill shavings,
or even sawdust, and a
synthetic resin or other suitable
binder, which is pressed
and extruded
•It is a composite material
Engineered wood
Particle board

43. • made by breaking down
hardwood or softwood residuals
into wood fibres, often in
a delibrator, combining it
with wax and a resin binder, and
forming panels by applying
high temperature and pressure
• MDF is generally denser
than plywood
•It is made up of separated fibres
• stronger and much denser
than particle board
Engineered wood
Medium Density Fiber board

44. • also called hardboard
• made out of exploded wood
fibres that have been highly
compressed
• It differs from particle board
in that the bonding of the
wood fibres requires no
additional materials,
although resin is often added
•Unlike particle board, it will
not split or crack
Engineered wood
High Density Fiber board