The document discusses the structural properties and types of timber used in construction, highlighting differences between hardwood and softwood, as well as various timber framing techniques including trusses and cruck frames. It details the design considerations for dhajji dewari buildings, emphasizing stability and joint types in timber structures. Additionally, the advantages and disadvantages of using timber as a building material are explored, underlining its thermal, acoustic, and aesthetic properties alongside potential issues related to moisture and deterioration.

1. BUILDING CONSTRUCTION & MATERIALS – II
GROUP 3
TOPIC:
STRUCTURAL PROPERTIES OF TIMBER
GROUP MEMBERS:
ZAINAB MUZAFFAR FARIYA RIYAZ SAQIB NAZIR
LABEEB QASHU AZRA FATIMA UBAID UR REHMAN

2. TIMBER STRUCTURES

3. INTRODUCTION
 Any wood used for the construction purposes is called as
timber.
 Lumbar is the wood material roughly sawn and cut into
length.
 Timber might be obtained from different kinds of trees
all around the world.
 Selection of timber in different parts of the building may
depend on different factors such as,
• Durability .
• Finish.
• Availability.

4. HARDWOOD SOFTWOOD
• Hardwood producing trees are
generally flowering trees, have
broad leaves and typically
deciduous,(shedding and
regrowing leaves annually).
• Cellular structure is complex. The
longitudinal cells of hardwood are
of two types
1) small cavities –provide strength
2)large cavities-conduct food
Wood grain pattern increases
density and workability.
• Softwood producing trees do not
bear flowers and have a single
main stem and are evergreen.
• All longitudinal cells are of
same type and almost the same
size,these provide strength to the
tree
Types of timber

6. HARDWOOD
• Hardwoods are
commonly used for
finishing floors.Due to
interesting grain
structure.They are used
for wall
paneling,cabinets,
furniture.
• More expensive
SOFTWOOD
• Softwood trees mature
faster,hence because of
the relative abundance
are commonly used for
structural framing.
(floors,ceilings,joists,raf
ters etc
• Less expensive.

7. HARDWOOD
• Transverse cells called
rays (perpendicular to
the longitudnal cells)
provide transverse
strength.
• Ray cells are more
prominent,due to which
hardwoods show a
more interesting grain
structure.
SOFTWOOD
• Transverse cells called
rays provide transverse
strength
• Ray cells are not more
prominnent,thus show
less interesting grain
structure.

11. ELEMENTS OF A TIMBER FRAME

12. TRUSS
• A framework, typically consisting of rafters, posts, and
struts, supporting a roof, bridge, or other structure.
Types of trusses
1.Closed truss
2.Open truss

13. ELEMENTS OF TRUSS

14. ELEMENTS OF TRUSS

15. CLOSED TRUSS
1. KING POST TRUSS
• For spans
greater than 5
m and less
than 9 m.
• Framework
consisting of
two principal
rafters, one
tie beam, two
struts and a
king post.

16. Joints
Joint at the feet of king post
Gibs , Cotters and Three way strap

17. Joints
Joint at purlin or at head of Joint at the head of king post Strut point.

18. 2.QUEEN POST TRUSS
• For spans greater
than 9 m and less
than 14 m
• Framework
consisting of two
principal rafters,
two queen posts,
one straining
beam , two
inclined struts
and a straining
sill.

19. Detail Of Joints
Joint at the feet of queen post Joint at the head of queen post

20. OPEN TRUSS
1.HAMMER BEAM TRUSS
• Constructed
by omitting
the middle
part of tie
beam.
• Spans over
20 m .

21. 2.Scissor Truss
• Scissors trusses are
used almost entirely in
building construction to
support a pitched roof,
where a sloping or
raised ceiling surface is
desired.
• It is a kind of truss in
which the bottom
chord members cross
each other, connecting
to the angled top
chords at a point
intermediate on the
top chords' length,
creating an appearance
similar to an opened
pair of scissors.

32. CRUCK FRAME
A CRUCK FRAME IS A CURVED TIMBER MEMBER, ONE OF A
PAIR, CURVED INWARDS, WHICH SUPPORTS THE ROOF OF
A BUILDING

33. CRUCK TIMBER FRAMES
.

34. TYPES OF
CRUCK FRAMES:
1. FULL CRUCK OR
TRUE CRUCK
2. UPPER CRUCK
3. JOINTED CRUCK
4. BASE CRUCK
5. RAISED CRUCK

35. .
* THE BLADES, STRAIGHT OR CURVED, EXTEND FROM THE FOUNDATION NEAR
THE GROUND TO THE RIDGE.
* A FULL CRUCK DOES NOT NEED A TIE BEAM & MAY BE CALLED A ‘FULL CRUCK’,
& IF A TIE BEAM IS USED, THEN ITS CALLED ‘ FULL CRUCK -CLOSED’
1.
TRUE CRUCK OR FULL CRUCK:

37. 2.
UPPER CRUCK:
IN UPPER
CRUCK,
THE
BLADES
RUN FROM
FLOORBEA
M LEVEL UP
TO THE
APEX OF
THE
BUILDING

38. 3.
JOINTED CRUCK:
• TWO MEMBERS
ARE JOINED TO
FORM A CRUCK.
HERE, A POST
RUNS UP TO
TOPPLATE LEVEL
WHERE IT
FLARES OUT
INTO THE ROOF
ANGLE. THERE,
IT IS JOINED
WITH A
STRAIGHT
PRINCIPLE
RAFTER.

39. 4.
BASE CRUCK:
THE CRUCKS ARE CUT FROM THE TREE WHERE A MAIN BRANCH FORMS THE CORRECT ANGLE
TO THE TRUNK. THE REST OF THE BRANCHES ARE CUT AWAY & THE TRUNK & BRANCH ARE
SQUARED OFF, THEN THE WHOLE UNIT IS CUT IN HALF, LENGTHWISE, TO FORM TWO
MATCHING BLADES.

40. 5.
RAISED CRUCK:
THE BLADES LAND ON MASONRY WALL & EXTEND TO RIDGE

41. Joints in timber structures
1. Butt joint
•It is the simplest joint.
•It is the weakest joint
and relies in some form
of reinforcement or glue.
Butt joint

42. 2.Mortise and tenon
•It has been used for centuries by
woodworkers because of its high
strength.
•It is usually used when two
members are at held at 90
degrees or slightly less than 90
(strongest when at 90 degrees).

43. 3.LAP JOINT
•It is made by halving the the
thickness of members at the
joint and fitting them together.

44. 4.Dowel joint.
Dowels are rounded pins used to strengthen a
joint.
Dowel joint

45. 5.Finger joint.
Multiple grooves are cut from plank leaving multiple protruding peaks or
fingers which interlock.

46. 6.Birdle joint.
•It is similar to tenon and mortice joint but the difference is that the
tenons and mortice are cut to full width of tenon member.
•Mostly used to fix rails with stiles.

47. 7.Splice joint or scarf joint
It is used to join two members end to end.

48. 8.Bird’s mouth joint.
• It is generally used to connect roof rafter to top plate of a
supporting wall
• The notch in the rafter has the shape odf birds mouth.

49. 9.Tongue and groove joint
•It joins two members end to end.
•The tongue projects a little less than the depth of groove.

50. Hammer and beam truss details
dowels
tenons
mortise

51. Post and principle rafter details
rafter
post
mortise
beam

52. Lower strut to king post
dowels
King post
strut
Tie beam

53. Four beams to a post

54. Dhajji dewari
.

55. introduction
DHAJJI DEWARI IS A TIMBER FRAME WITH STONE & EARTH INFILL,
TYPICALLY USED IN THE MOUNTAIN REGIONS OF SOUTH ASIA. SIMILAR
CONSTRUCTION IS USED AROUND THE WORLD, UNDER DIFFERENT
NAMES. HIMIS IS A TURKISH VARIATION OF THIS TECHNIQUE, IN
PORTUGAL, BUILDERS HAVE USED GAIOLA POMBALINA & ITALY USES
CASA BARACCATA TIMBER FRAME.
DHAJJI DEWARI {PERSIAN FOR “ PATCH QUILT WALL”}IS A
TRADITIONAL BUILDING TYPE FOUND IN THE WESTERN HIMALAYAS.
SUCH HOUSES ARE FOUND IN BOTH THE PAKISTANI & INDIAN SIDES OF
KASHMIR. THIS FORM OF CONSTRUCTION IS ALSO REFERRED TO IN THE
INDIAN STANDARD CODES AS BRICK NOGGED TIMBER FRAME
CONSTRUCTION.

56. EXAMPLES

57. TERMINOLOGY

59. JOINTS

61. JOINERY

62. .

63. BRACING PATTERNS

64. DHAJJI BUILDING IN DETAIL
DHAJJI BUILDINGS ARE TYPICALLY ONE TO FOUR STORIES TALL & THE ROOF MAY
BE A TIMBER OR MUD ROOF OR A PITCHED ROOF WITH METAL SHEETING. THE
FLOORS OF THESE HOUSES ARE MADE WITH TIMBER BEAMS THAT SPAN BETWEEN
WALLS. TIMBER FLOOR BOARDS, WHICH SPAN OVER THE FLOOR BEAMS WOULD
TRADITIONALLY BE OVERLAID BY A LAYER OF CLAY OR MUD.
PLA
PLAN OF A DHAJJI BUILDING

65. DFF
• FGGG

66. SECTION OF A DHAJJI BUILDING

67. EXPLODED MODEL OF A DHAJJI BUILDING

68. MODEL OF A DHAJJI BUILDING
TIMBER FRAMES FOR DHAJJI BUILDINGS

69. JOINTS
JOINING DETAILS AT THE CORNER
DPC IS NOT PROVIDED.
Timber ground beam
(or sill beam) raised
above the ground to
protect the timber
frame from rotting

70. .
JOINERY DETAILS AT THE TOP

71. FOUNDATION
• HSGBHGHIH
Strip footing made from stone with concrete Foundation below plinth beam
capping and embedded steel reinforcement
Bolts in the foundation to tie-up plinth timber Base plate corner detail & Bolt anchor
holes

72. INFILL
WALL/BRACE READY TO RECEIVE INFILL WALL/BRACE RECEIVING THE INFILL
INTERNAL VIEW OF THE
WALL/BRACE AFTER
RECEIVING THE INFILL

73. IMPORTANT FACTORS TO BE CONSIDERED
WHILE DESIGNING DAJJI BUILDINGS
1. PROPORTIONS 2. SHAPE

74. 3. PLANNING 4. BALANCE
5. EXTERNAL WALLS 6. SHOP WINDOW FRONT

75. 1. HIPPED ROOFS ARE STRONGER
THAN PITCHED ROOFS BECAUSE
THEY DON’T FALL OVER.
2. IF A PITCHED ROOF IS USED,
IT MUST BE BRACED INSIDE

76. 3. MORE STOREYED BUILDINGS ARE CONSTRUCTED, BUT
TWO STOREYED BUILDINGS HAVE THE BEST STABILITY

77. 4. THE LENGTH OF THE WALL MUST NOT EXCEED 15 FEET.
IF THE WALL IS LONGER, IT HAS TO BE BRACED IN
BETWEEN, EITHER BY A BUTTRESS WALL OR A BEAM WELL
CONNECTED TO ANOTHER WALL IN THE SAME DIRECTION

78. OPENINGS
1. WINDOWS & DOORS MUST BE MINIMISED AS THEY ARE THE WEAK POINTS
2. SMALLER OPENINGS ARE BETTER THAN BIG ONES
3. AVOID PLACING ALL THE WINDOWS ON THE SAME SIDE
4. KEEP WINDOWS & DOORS ATLEAST 2 FEET FROM THE CORNERS

79. 5. VERANDAS SHOULD NOT BE
DEEPER THAN 1/3 OF THE
DEPTH OF THE BUILDING
6. VERANDAS PLACED IN THE
MIDDLE OF THE BUILDING
ARE BETTER

80. EARTHQUAKE RESISTANCE

81. SIMILAR CONSTRUCTION
TECHNIQUES AROUND THE
WORLD:
HIMIS – TURKEY
GAIOLA POMBALINA - PORTUGAL
CASA BARACCATA – ITALY
AND MORE……

82. HIMIS [TURKEY]
EXAMPLES OF HIMIS THROUGHOUT TURKEY

83. .
BUILDINGS IN TURKEY MADE BY HIMIS TECHNIQUE

84. GAIOLA POMBALINA [PORTUGAL]
BUILDINGS IN PORTUGAL MADE BY GAIOLA POMBALINA TECHNIQUE

85. CASA BARACCATA [ITALY]

86. .
FRAME & EXAMPLE OF A STRUCTURE MADE
WITH CASA BARACCATA TECHNIQUE

87. Some more
examples of
similar types of
construction
• .

88. Similar types of construction from
Nicosia, Cyprus

89. Similar types of construction from
Port au prince, Haiti

90. Similar types of construction from
Venezuela

91. Similar types of construction from
Punjab, India

92. Similar types of construction from
France

93. Similar types of construction from
South America

94. LOG CONSTRUCTION
• It is the method of construction of a structure by
stacking up logs on one another horizontally.
• Logs are placed in place with the help of tongue and
groove joint.
• Logs are interlocked at corners with the help of
notching

95. Log profiles

96. 1. Double round
•It gives round look on interior as well as exterior.
Double round profile with double
tongue and groove joint
Single tongue and groove
joint

97. 2. D profile
•Flat interior walls and
round appearance on the
exterior.
Tongue and groove joint
between logsD profile

98. 3. Square or rectangular
•Logs produce flat interior and exterior walls.
Single tongue and groove joint
Double tongue and groove joint

99. 4. Swedish cope
•A concave notch is made at the bottom of log so that it sits over the log lying
below it.
Swedish cope profile Logs stacked over one another

100. 5. Bevelled or shiplap

101. Corner details
1. Butt and pass corner
•One log is intercepted by
the other coming at 90
degrees.
•Logs exceed corners
alternatively.
Corner detail

102. 2.Dovetail corner
•Logs at corners are held
together with the help of
dovetail profile.
•This type of corner resists
sliding movements because of
firm interlockinf pattern
•It is aesthetically more
pleasing

103. 3. saddle notch corner
•One log sits on the saddle shaped notch of other ,allowing
every log to exceed the corner
Saddle shaped notch
Corner detail

104. 4. Corner post
•Every log meeting at corner is
attached to a log post
•Thus giving us a vertical
member at corner.

105. PROS & CONS OF TIMBER STRUCTURE
Wood is an organic, Hygroscopic and
Anisotropic Material. It has good thermal,
acoustic, electrical, mechanical, aesthetic
properties .These Properties are very
suitable to use it as a building material

106. Advantages
• Thermal Properties:-
Wood is 400 times better as a thermal insulator than steel and 14 times
better than concrete.
Wood also has significant thermal properties, retaining heat from the day
and releasing at night.
• Acoustic Properties:-
Sound isolation is based on the mass of the surface. Wood, as alight
material, is not perfect for sound isolation, but it is ideal for sound
absorption. Wood prevents echo and noise by absorbing sound. For this
reason it is used in concert hall
• Electrical Properties:-
Resistance to electrical current of a compeletely dry wood is equal to that
of phenol formaldehyde. An oven dried wood is very good electrical
insulator.

107. .• Mechanical Properties:-
Tensile strength of wood = 0.6/cm3
Specific Gravity of wood = 100 N/mm2
Tensile strength of steel = 7.89/cm3
Specific Gravity of steel = 500 N/mm2
• Aesthetic Properties:-
Wood is a decorative material when considered as an
aesthetic material. Each tree has it own color, design and
smell the design of the tree does not change according to the
way it sliced.

108. .
• Building Time:-
Bricks and block frame buildings take longer to construct
because of the time it’s takes to built walls, plaster them,
throw the concrete floors, and for the mortar, plater and
concrete to dry properly.
• Timber frame homes can be built in freezing
temperatures
• More flexible design:-
Timber frames can be crafted into almost any shape and are
perfect for an pen plan style home.
• Timber is green and eco-friendly:-
Most forested trees are re-planted after they are felled and
this makes them a good option.

109. Disadvantages
• Shrinkage and swelling of wood:-
Wood is a hygroscopic material. This means that it will absorb
surrounding condensable vapors and loses moisture to air
below the fixer saturation point.
• Deterioration of wood:-
The agent causing the deterioration and destruction of wood
fall into two categories: Biotic( biological) and Abiotic(non-
biological)
Biotic agents include decay and mold fungi, bacteria and
insects.
Abiotic agents include sun, wind, certain chemicals and fire.

110. .
• Susceptible to damp conditions;-
Where a timber frame home has been poorly built in an area
where wet conditions dominate, damp problems can occur.
When exposed to constant or long term dampness wood will
eventually rot.