Any kind of structure made of pine, including furniture, enclosures, boxes or storage areas, need to be waterproofed so that the wood will not be damaged in case of rains or flooding. Water damage will ruin a piece of furniture because the wood will rot, become soft and decay. Furniture and other pine structures are an investment and should be maintained regularly to keep them in good shape. The process is fairly simple and inexpensive, but will require some time to finish.
Purchase an oil-based primer or stain and water sealant at your local hardware store. Disassemble your furniture or other pine structure into separate pieces, if necessary.
Paint one or two layers of water sealant onto each pine piece. Allow the pieces to dry.
Brush over each piece with the oil-based primer or stain ensuring that the entire surface is covered. Let each piece dry thoroughly.
Reassemble the pieces of pine, if necessary. Reapply the sealant and primer again if you spot any signs of water damage.