timber headlineheadline 1.carpentry general 2.advantages of timber 3.use of timber. 4. qualities of...

timbertimberHEADLINE

1. Carpentry General2. Advantages of Timber 3. Use of Timber.4. Qualities of Good Timber.5. Defects in Timber.6. Methods of stacking.

7.

Carpentry Carpentry GeneralGeneral Timber has been in very common use for- Timber has been in very common use for-

engineering purposes since ancient times.engineering purposes since ancient times.

Even today there are certain works, where timber Even today there are certain works, where timber is considered as the most ideal material.is considered as the most ideal material.

Today although materials like steel, cement, stone Today although materials like steel, cement, stone bricks etc. have occupied lot of field, where timber bricks etc. have occupied lot of field, where timber was almost used, still timber continues to be an was almost used, still timber continues to be an important structural material.important structural material.

There is difference between terms There is difference between terms timber and woodtimber and wood. . Wood includes all types of wood which may be Wood includes all types of wood which may be burning wood, structural wood, furniture wood etcburning wood, structural wood, furniture wood etc. . But wood suitable for use as a structural material is But wood suitable for use as a structural material is called timbercalled timber..

So we can say: Wood is usually used to refer to the So we can say: Wood is usually used to refer to the material in its natural state...timber refers to it after it material in its natural state...timber refers to it after it has been modified by man. So you go to the forest to has been modified by man. So you go to the forest to collect wood for the fire, and to the DIY store to get collect wood for the fire, and to the DIY store to get timber for doing up your housetimber for doing up your house

Carpentry Carpentry GeneralGeneral

Timber is obtained from trees. Timber denotes structural Timber is obtained from trees. Timber denotes structural wood. A standing living tree is known as standing wood. A standing living tree is known as standing timber.timber.Rough timber.Rough timber.

When tree has been cut and its stem and branches When tree has been cut and its stem and branches are roughly converted into pieces of suitable lengths.are roughly converted into pieces of suitable lengths.Converted timber

When roughly converted timber is further sawn When roughly converted timber is further sawn and converted into commercial size the planks, logs, and converted into commercial size the planks, logs, battens, posts, beams, etcbattens, posts, beams, etc

Carpentry Carpentry GeneralGeneral

It is easily available every where.It is easily available every where. Its salvage Its salvage التعديلالتعديل value is high.value is high. It can be easily transported by converting large It can be easily transported by converting large

pieces into smaller pieces.pieces into smaller pieces. Working on timber is easy. Timber constructions Working on timber is easy. Timber constructions

can be easily repaired. Additions and alterations to can be easily repaired. Additions and alterations to timber structures can be easily done.timber structures can be easily done.

It can be easily jointed.It can be easily jointed. In marine works, timber is considered as an ideal In marine works, timber is considered as an ideal

material as it does not corrode. Cement and iron material as it does not corrode. Cement and iron structures corrode in sea water, if they are not structures corrode in sea water, if they are not protected with special preservative.protected with special preservative.

Carpentry Carpentry __Advantages of TimberAdvantages of Timber

Being light in weight, it is preferred for building Being light in weight, it is preferred for building works in earth quake prone regionsworks in earth quake prone regions المناطق المناطق

للزالزل للزالزل المعرضة ..المعرضة It is an excellent material for decorative and general It is an excellent material for decorative and general

use furniture. Lot of other internal decorations can use furniture. Lot of other internal decorations can be carried out with it.be carried out with it.

It can with stand, shocks better than iron and It can with stand, shocks better than iron and concrete.concrete.

It is good insulator of electricity and heat.It is good insulator of electricity and heat. It is good sound absorbing material.It is good sound absorbing material. Timber can be easily strengthened by attaching Timber can be easily strengthened by attaching

steel or other material with it. steel or other material with it.

Carpentry Carpentry __Advantages of TimberAdvantages of Timber

It can be said that there is no Engineering field, It can be said that there is no Engineering field, where timber is not used one way or the other.where timber is not used one way or the other.

Uses of timber are numerous. Some of its important Uses of timber are numerous. Some of its important uses are given as follows:uses are given as follows:

It is very much used for railway track sleepers.It is very much used for railway track sleepers. It can be used inform of piles, vertical posts, beams, It can be used inform of piles, vertical posts, beams,

doors and windows.doors and windows. It can also be used as members of roofing trusses.It can also be used as members of roofing trusses. It is an important material for furniture-makingIt is an important material for furniture-making It is used for floors, ceiling, and partition walls.It is used for floors, ceiling, and partition walls.

Carpentry Carpentry __ Use of TimberUse of Timber

It It is used as form-work for cement concrete is used as form-work for cement concrete structures. structures.

It is very much used in making sports. goods, It is very much used in making sports. goods, musical instruments, well curbs, agricultural musical instruments, well curbs, agricultural implementsimplements الزراعية التنفيذية الزراعية العمليات التنفيذية .etc., etc , العمليات

Packing cases are mostly made from soft timber.Packing cases are mostly made from soft timber. It is very much used for timbering the deep. It is very much used for timbering the deep.

TrenchesTrenchesالخنادقالخنادق .. Railway coaches and wagonsRailway coaches and wagonsالعرباتالعربات are also made are also made

from high class timber.from high class timber.

Carpentry Carpentry __ Use of TimberUse of Timber

Following are the qualities of good timber.Following are the qualities of good timber. A good timber should be hard and durable.A good timber should be hard and durable.

It should be capable of resisting the actions of It should be capable of resisting the actions of fungifungiالفطرياتالفطريات , chemicals and physical agencies., chemicals and physical agencies. The fibers of the timber should be straight and The fibers of the timber should be straight and

compact.compact.The timber should be free from knotsThe timber should be free from knotsالعقدالعقد , twists, , twists,

upsets, burlsupsets, burlsالعقدالعقد shakes, flawsshakes, flawsالعيوبالعيوب etc.etc. Its color should be dark. It should be obtained Its color should be dark. It should be obtained

preferably from heart wood. Color should be uniform.preferably from heart wood. Color should be uniform. It should be properly seasoned.It should be properly seasoned. صحيح بشكل صحيح مجهز بشكل مجهز

Its freshly cut surface should smell sweetIts freshly cut surface should smell sweet..

Carpentry Carpentry __ Qualities of Good TimberQualities of Good Timber

Its weight should be heavy.Its weight should be heavy.It should be easily workable. It should not clog It should be easily workable. It should not clog يعيقيعيقthe the

teeth of sawteeth of saw and should be capable of being easily and should be capable of being easily planned.planned.

Timber should be tough i.e., it should be capable of Timber should be tough i.e., it should be capable of resisting shocks.resisting shocks.

It should be able to withstand the weathering affects.It should be able to withstand the weathering affects.It should be strong enough to withstand bending, direct It should be strong enough to withstand bending, direct

and shear effects efficiently.and shear effects efficiently.A clear ringing sound should be emitted by the timber A clear ringing sound should be emitted by the timber

when struck. Heavy dull sound indicates decayed timber.when struck. Heavy dull sound indicates decayed timber.It should offer adequate fire resistance.It should offer adequate fire resistance.

It should be elastic It should be elastic

Carpentry Carpentry __ Qualities of Good TimberQualities of Good Timber

CarpentryCarpentry__ Defects in TimberDefects in Timber

Defects that develop after Defects that develop after felling the tree.felling the tree.

BowBow CupCup

TwistTwist Radial shakesRadial shakes

WaneWaneالتضاؤلالتضاؤل Diagonal grains Diagonal grainsالقطريالقطري

Defects that develop after Defects that develop after felling the tree.felling the tree.

BowBow CupCup

TwistTwist Radial shakesRadial shakes

WaneWaneالتضاؤلالتضاؤل Diagonal grains Diagonal grains القطريالقطري

The defects that usually occur in the timber may be classified into two categories as follows:

Defects that develop Defects that develop during growth of the tree.during growth of the tree.

ShakesShakes Twisted timberTwisted timber

Upsets or ruptureUpsets or rupture KnotsKnots

Wind cracks Wind cracks Burls Burls

Defects that develop Defects that develop during growth of the tree.during growth of the tree.

ShakesShakes Twisted timberTwisted timber

Upsets or ruptureUpsets or rupture KnotsKnots

Wind cracks Wind cracks Burls Burls

1.Defects that develop during growth of tree1.Defects that develop during growth of tree

have been briefly discussed as follows:have been briefly discussed as follows:

1.11.1 Shakes. Shakes. This is most serious type of defect in This is most serious type of defect in timber. These are sort of cracks which partly or timber. These are sort of cracks which partly or completely separate the fibers of wood. A shake is completely separate the fibers of wood. A shake is nothing, but separation of the timber along the nothing, but separation of the timber along the grains. Shakes may be of several types.grains. Shakes may be of several types.


1.1.11.1.1 Star shakesStar shakes

These are radial cracks or These are radial cracks or splits that extend from bark splits that extend from bark towards the sap wood. They towards the sap wood. They usually remain confined up to usually remain confined up to the plane of sap wood only. The the plane of sap wood only. The cracks are widest at the cracks are widest at the circumference and go on circumference and go on narrowing as they proceed narrowing as they proceed towards the Centre of the tree. towards the Centre of the tree.


Reasons of star shakeReasons of star shake

Star shakes usually Star shakes usually develop due to fierce heat develop due to fierce heat and frost and frost

When logs having this When logs having this defect are sawn they defect are sawn they usually separate out into a usually separate out into a number of pieces and number of pieces and hence become useless.hence become useless.


Star shakesStar shakes

1.1.2 1.1.2 Heart shakes.Heart shakes.These splits or cracks occur in These splits or cracks occur in the central part of the trees. the central part of the trees. There are widest at the centre There are widest at the centre and go on narrowing as they and go on narrowing as they proceed towards outside. This proceed towards outside. This defect usually occurs in over-defect usually occurs in over-matured trees. This defect is matured trees. This defect is usually caused due to shrinkage usually caused due to shrinkage of the heart wood. Heart shakes of the heart wood. Heart shakes divide the tree cross-section into divide the tree cross-section into several parts. Straight running several parts. Straight running heart shake is not as serious as heart shake is not as serious as twisted heart shake.twisted heart shake.


1.1.3Cup shakes. 1.1.3Cup shakes.

This defect develops curved slit This defect develops curved slit between successive annual rings. The between successive annual rings. The split does not run for the full split does not run for the full circumference of the annual rings. circumference of the annual rings.

This defect usually develops due to 1. This defect usually develops due to 1. unequal growth. unequal growth.

2. Another possible reason for their 2. Another possible reason for their development may be contraction of development may be contraction of timber under atmospheric changes timber under atmospheric changes together with the twisting action of together with the twisting action of strong winds.strong winds.


1.1.4Ring shakes. When cup shake defect runs for full When cup shake defect runs for full

circumference of the annual ring, it is called circumference of the annual ring, it is called ring shake. It is more serious than cup shake.ring shake. It is more serious than cup shake.

1.1.5 Radial shakes. They are similar to star shakes. They They are similar to star shakes. They

are numerous, fine and irregular. They are numerous, fine and irregular. They usually occur when felled tree is usually occur when felled tree is

exposed to sun for seasoning. The exposed to sun for seasoning. The cracks run for a short distance from cracks run for a short distance from

bark to-wards the centre and then bark to-wards the centre and then follows the course of an annual ring follows the course of an annual ring

and ultimately goes towards the pith.and ultimately goes towards the pith.


1.2 Twisted fibers1.2 Twisted fibers..

They are caused by twisting of young trees They are caused by twisting of young trees constantly in one direction under the action constantly in one direction under the action

of strong prevalent winds. Timber with of strong prevalent winds. Timber with twisted fibers is unsuitable for sawing. The twisted fibers is unsuitable for sawing. The timber having this defect is mostly used for timber having this defect is mostly used for

posts and poles in an unsawn condition posts and poles in an unsawn condition


1.3 Upsets or ruptures.1.3 Upsets or ruptures.

تمزقات او تمزقات اضطرابات او اضطراباتThis defect is caused due to This defect is caused due to

injury suffered by wood fibers injury suffered by wood fibers by crushing or compression. by crushing or compression. Upsets are mainly due to Upsets are mainly due to improper felling of tree and improper felling of tree and exposure of tree in its young exposure of tree in its young age to fast blowing wind. age to fast blowing wind. This This defect indicates change in defect indicates change in direction of wooden fibers.direction of wooden fibers.


1.4 Knots.1.4 Knots. Knots are generally developed at the bases of branches Knots are generally developed at the bases of branches cut off from the tree. This phenomenon ultimately results cut off from the tree. This phenomenon ultimately results in the formation of dark, hard rings, known as knots. As in the formation of dark, hard rings, known as knots. As knots break the continuity of the wooden fibers, they knots break the continuity of the wooden fibers, they form a source of weakness. form a source of weakness. The amount of weakness The amount of weakness caused by the knot depends upon the position, size, and caused by the knot depends upon the position, size, and degree of grain distortion around itdegree of grain distortion around it. Knot is the most . Knot is the most commonly encountered defect of wood. commonly encountered defect of wood.


It is impossible to procure timber free of knots.It is impossible to procure timber free of knots.Knots may be dead, live loose, Knots may be dead, live loose, or tight. Tight knots are not or tight. Tight knots are not objectionable unless they objectionable unless they are too large. Their presence on are too large. Their presence on tension members is objectionabletension members is objectionable. It is very difficult to plane. It is very difficult to plane the timber at knots.the timber at knots.


1.5 Wind cracks.1.5 Wind cracks. The outer layers of a The outer layers of a standing tree suffer from standing tree suffer from

the effect of shrinkage the effect of shrinkage due to atmospheric due to atmospheric

agencies. This causes agencies. This causes cracks on the outer cracks on the outer surface only. These surface only. These

cracks are known as cracks are known as wind cracks.wind cracks.


2. Defects that develop after felling the tree.2. Defects that develop after felling the tree.Conversion of timber is done almost immediately after

felling The tree. The defects that may develop after felling the tree and also during conversion and

seasoning are the following:

2.1 Bow:2.1 Bow: when planks of converted of timber shrink when planks of converted of timber shrink and bend in curved form , in the direction of length.and bend in curved form , in the direction of length.


2.2 Cup:2.2 Cup:

this defect is indicated when this defect is indicated when wooden planks bend in curved wooden planks bend in curved

from in transverse direction.from in transverse direction.

2.3 Twist2.3 Twist

A plank which has distorted spirally A plank which has distorted spirally along its length along its length


Methods of Methods of

stackingstacking.. Before seasoning, the timber should be stacked in yards Before seasoning, the timber should be stacked in yards

so as to protect the timber from direct sun.so as to protect the timber from direct sun.

Ends of logs should be protected against splitting by Ends of logs should be protected against splitting by

applying anti-Splitting compositions and stacked on applying anti-Splitting compositions and stacked on

foundations in closed stacks in one or more layers.foundations in closed stacks in one or more layers.


1.One and nine method of 1.One and nine method of stacking.stacking.

This method of stacking This method of stacking timber is most suitable for timber is most suitable for moderately heavy moderately heavy coniferous sleepers in coniferous sleepers in hot hot climatesclimates and for heavy and for heavy timbers in timbers in moist climatesmoist climates. .


2. Close crib method. 2. Close crib method.

This method of stacking timber This method of stacking timber

allows reduced air circulations allows reduced air circulations

and thus slows down the pace and thus slows down the pace

of seasoning. This method is of seasoning. This method is

recommended for stacking recommended for stacking

heavy structural timbers like heavy structural timbers like in in

hot and dry localities.hot and dry localities.


Paneled doors

Flush doors

timber timber End

timber headlineheadline 1.carpentry general 2.advantages of timber 3.use of timber. 4. qualities of...

Documents

timber structures

standing timber

rough timber

terms timber

soft timber

timber constructions

qualities of good timber

high class timber