Composite lumber refers to decking or 2 x material that is made up of a mixture of pigments, ultraviolet inhibitors, borate preservatives, wood fibers, and recycled plastic (often shredded polyethylene). Most manufacturers offer a warranty of 25 years and as much as a lifetime warranty. Composite lumber cleans easily with a simple scrubbing of soapy water. Low end composites are usually priced 3-4 times more than pressure treated pine but will often offset those additional costs with reduced maintenance, repair, and cleaning costs. Composite lumber is prone to permanent scuff, staining, and can be hot under foot in direct sunlight. Some of styles of composite lumber are: Weathertight, Textured Grain, Two Faced (One side wood grain one side brushed), Plastic Wrapped (Resin Covered), Embossed Grain, Waethered Wood, Paper Board.
Plastic lumber is very different from composite lumber and is typically made of PVC (polyvinylchloride). It is 99% virgin PVC plastic and is harder than Polyethylene so it doesn’t scratch as easily. Also since there are no wood fibers present, it won’t absorb water or retain food stains.Plastic decking is limited to only 3-4 colors and can be as pricy as top of the line composite. Also, Plastic/PVC lumber is not environmentally friendly as it has little or no recycled content.
Some common profiles are:
-Slotted – Grooves along sides, accepts hidden fasteners. 2.5 pounds per foot
-Solid – Face fastened or Edge Fastened, Two usable sides. 2.5 pounds per foot
-Open Flange – Saves Weight while maintaining stiffness, accepts hidden fasteners only – 2.2 pounds per foot
-Scalloped – Indented underneath to minimize weight, fastened on top or side – .5 pounds per foot
– Stiffer and 25% lighter than solid board, end caps to avoid bug nesting – 1.9 pounds per foot
Installation: Joists must be spaced minimum of 16″ or the decking will sag over time. It is recommended that screws be placed 3/4″ from all edges and ends as any less may crumble the material. Leave expansion joints between sides and butt ends.