Defects in timber Objectives

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DEFECTS
IN TIMBER
Written by
JOHN STAGG
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Defects in Timber

• Defect, in this case, means anything that
  effects the structural integrity or appearance of
  timber.
• Remember
• There are as many potential defects as there are
  uses for timber.

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Defects in Timber

• By the end of this session you should be able to
• Identify three defects effecting timber
• State the remedial action to be taken in each of
  the three cases

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Things that attack timber
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Defects in timber

• Timber is a natural material that is prone to
  defects.
• One of these is the tendency to split if it is
  put under stress from rapid drying, poor felling
  or de-lamination of the growth rings.
• These defects are all known as Shakes

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Shakes
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What other defects occur in timber?

• Dry rot

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What other defects occur in timber?
sap

• Blue stain

heart
pith
juvenile
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What other defects occur in timber?

• Insect attack

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What other defects occur in timber?
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Further considerations

• What other defects may occur in timber or timber
  structures?
• What circumstance or working load may, over time,
  cause timber or timber structures to fail?

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Construction Department
End
Defects in Timber
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END