The gross proceeds of the sale of timber when sold in the original state of production or preparation for sale and when sold by the producer thereof or by members of his immediate family are exempted from payment of sales or use tax, whichever would otherwise be considered to apply. Nothing contained herein, however, shall be construed to exclude from the measure of the tax the gross proceeds of the sale or sales of timber or timber products treated with wood preservatives.
S.C. Code Regs. § 117-311.3