Outdoor Lumber is Thermally Modified Bamboo. An initial thermal process strips bamboo of sugars from the plant rendering a robust fiber. Fibers are placed into a form and compressed under tremendous pressure for prolonged periods. A simple carbon-based resin is added to the material matrix during a second heating phase to convert the resin/fiber mix to make a solid fiber block. The bamboo fiber is cured and milled with high precision machining into many form factors. Some forms include decking, siding, fencing, tongue & groove, and trim fascia boards. There are virtually no pores or space in the material. It is harder than Ipê but grows like grass.