Wooden lintels are the oldest type of lintels. It is even now used in areas where timber is abundantly available. However, the risk of using wooden lintels is that they are susceptible to catch fire and liable to decay by rot or termite.
Single piece of timber is used for smaller spans. For larger spans, built-up sections are to be used. Built-up sections may be formed by using two or three timber pieces and bolted to serve as a lintel. Figure 19.8 shows a wooden lintel composed of two timber pieces and two distance or packing pieces. Bolts are provided through the packing pieces. Sometimes, in order to strengthen the wooden lintels, mild steel plates are placed at the top and bottom and such lintels are called as flitched lintels.
Figure 19.8 Wooden lintel
Following important aspects have to be given due consideration while designing a wooden lintel:
- Good quality woods like teak, rosewood, etc., without any defects should be used.
- Bearing of lintel should be adequate and it should rest on a mortar base to have a firm and uniform support.
- Width of lintel should be equal to the thickness of the opening and the depth 1/12th of the span 8 cm, whichever is greater.
- Relieving arches of brick or stone may be designed wherever heavy loads are anticipated.
- Wooden lintels help in securing the heads of frames of wooden doors and windows.
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