Straight Cuts on Composite Materials

• 1). Place a plank of composite decking material along the section where you will be installing it. Mark the place where the plank needs to be cut with the contractor's pencil.
  
  
• 2). Place the plank on your saw table or horse and put on your safety glasses. Make sure you place the plank face-down, as circular saw blades cut upward and may slightly splinter the finish of the side facing up.
  
  
• 3). Line up the guide marker or window on your circular saw with the line you made on the plank. Turn on the saw and cut through the entire plank, keeping your line straight.
  
  

Cutting Composite Material to Fit Around Obstructions

• 1). Place a piece of cardboard next to the obstruction you need your decking to fit around, like a deck post. Draw marks on the cardboard to represent the shape of the obstruction. Make sure that the template you draw is as close to the actual shape and measurements of the obstructions as possible to ensure a perfect fit.
  
  
• 2). Cut the cardboard template out with the utility knife.
  
  
• 3). Line up the template with the piece of decking you will be cutting and tape it into place. Measure the decking against the area it will be placed to make sure the template is in the right area of the plank. Use painter's or masking tape to prevent leaving any adhesive residue.
  
  
• 4). Face the plank so that the side that will be showing is facing up. Jigsaw blades cut down, so this will prevent the finish from splintering along the cut. Cut along the edge of the template with the jigsaw.