About Homemade Lumber Kilns

Wood that is used for structural supports and some other types of woodworking projects must be dried first. Drying wood reduces the moisture content so that it can be utilized for many purposes. A homemade lumber kiln is an inexpensive alternative to fossil fuel powered dehumidification kilns.

Many individuals are convinced of the importance of building solar kilns. Improperly dried wood may prove dangerous to the person sawing and to bystanders. Due to high humidity levels in many areas, it is difficult to dry lumber satisfactorily to stabilize it for construction utilization without the use of a kiln. Fossil fuel powered dehumidification kilns can be very expensive to purchase and operate adding to the price of wood at lumberyards.

Homemade lumber kiln plans may be adapted to various sizes and built to meet individual needs. Kiln size should be determined by the maximum dimensions of the wood to be dried. A moderate-sized kiln will dry 450 board feet of lumber in six weeks or less. Consideration must be given to the type of wood drying, as hardwoods take longer to dry than softwoods. The intensity of the sun, moisture level of the lumber and humidity will affect drying times. 

The roof angle affects the solar drying performance of the kiln; however, 45 to 55 degrees is generally suggested. Pressure treated lumber and exterior plywood should be chosen for construction purposes. The floor of the kiln should be insulated with blanket-style or solid foam, avoiding foil vapor barrier insulations. A flat black oil-based paint is applied to the top sheet of plywood on the kiln floor to prevent moisture seepage and for maximum solar absorption.