Timber as external material in building production simply means using timber on the external part of the building such as timber work covering, timber external walls, and timber external windows, doors and frames. Timber use practices in building production industry is endowed with a variety of tree species in her nature forests and in recent years there has been an increase in the establishment of exotic trees species such as pine and eucalyptus on plantations. Despite the abundance of wood resources, wood has been under utilized with a view that it is material to be avoided due to its perceived unreliability, variability and unknown properties.
Generally, timber research has been academic and has concentrated on a few tree species, resources have not explored the key indicators of wood strength such as bending stiffness and bending strength, they have concentrated on density which has been reported as poor surrogate strength. This is purely the reason timber users cannot accept lesser-known timber. Limited studies have been done to predict the allowance load from bad deflection relationship. This is probably the reason timber users prefer timber with proven truck record, a practice which unfortunately exerts pressure on well-known timber species leading to their building environment coupled with population growth and dwindling wood resources globally necessitates research into optional use of multiple trees species with quality control procedures.
The aim of the study was to examine timber use practices with emphasis on analyzing weakness and strength in the application of wood as an external material in building. Timber is a cellular material consisting of minute cell called fibre or trenched which have inter-communicating pits or values that allow water and solutions to be conducted through out the structure. The word timber described wood, which has been cut for use in building. Timber has many advantages as a building material. It is high weight material that is easy to cut, shape and join by relatively cheap and simple hand or power operated tools in the production of timber. Timber is used all parts of building such as farm work, doors and windows, frames, timber, wall plates, floors and also in roof carcass. Timber is a very important material in building production which helps to facilitate building construction. As a structural material it has favourable weight to lost of elasticity relations and coefficients of thermal expansion, values density and specific heat with sensible selection, fabrication and fixing and adequate impregnation or protection. It is a reasonable durable material in relation to the life of most building, wood burn at temperature of about 3500 and chairs, the chaired outer face of the wood protecting the unborn inner wood for period adequate for escape during fire in most building.
Timber is the greatest renewable resources in the building material field. As a building material, it has inherent characteristics which determine its application in construction with a recent better understanding of timber coupled with availability of sound structural design of timber structures and development of economical processing and presentation process, greater or more efficient use in building made of timber in construction. Generally, timber offers numerous advantages in construction application like beauty, workability, low cost per kg, high strength to weight ration, good electricity installation and low temperatures.