Once there was just dimensional lumber. A 2 x 4 was a 2 x 4 wherever a builder happened to go, the only difference perhaps being in what kind of timber from which the board had been milled.
Then came laminated materials like plywood, followed by the composites, starting with particle board. Now the list of man-made, or engineered materials is huge, including structural materials, decking, siding and trim. The use of such materials hopefully represents a way to save the felling of old growth forests to feed product demand in the building trades.
The idea of putting scrap materials – even sawdust – looks to be very sustainable at the basic level, it should be realized that not all the ingredients that go into engineered materials are not green or sustainable, especially when it comes to what types of glues or resins are used for manufacturing.
According to Technology at GCSE, Man-made boards are boards made up of smaller pieces of wood. “Their main advantages are that they can come in very big sizes since they are built from smaller pieces of wood, (whereas solid wood can only be as big as the tree it comes from) and man-made boards do not tend to warp and twist as easily when they are dried out or when they get damp.”
Wiki answers adds that engineered wood “includes a range of derivative wood products which are manufactured by binding the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials. These products are engineered to precise design specifications which are tested to meet national or international standards.”
Not only is wood used for engineered materials, other materials can be used to manufacture similar engineered products from other vegetable fiber materials such as rye straw, wheat straw, rice straw, hemp stalks, or sugar cane residue.
- Engineered wood can be designed to meet application-specific performance requirements.
- Large panels of engineered wood may be manufactured from fibers of small trees.
- Small pieces of wood, or wood with defects, can be used in many particle and fiber-based boards.
- Lower cost
Engineered wood products also have disadvantages:
- They require more primary energy for manufacture than solid lumber.
- Many of the formaldehyde-based adhesives are toxic – either during or after construction.
Wiki answers provides this convenient and useful list of man-made or engineered building materials: