Prevention of timber

• Timber is preserved to protect from attack of insects and from internal decay due to rots . 
• Good seasoning is the most effective mean of preservation . 
• Preservatives should be toxic to fungiand insects , chemical stable , able to penetrate timber and non-aggressive to surrounding materials , eg metals aggressive to surrounding materials , eg metal . 
• Various types of preservatives available . 
• Before applying preservative , timber should be well-seasoned other wise pores in timber will be blocked , causing decay due to entrapped moisture .