Carpeted computer rooms and roll-around office chairs do not work well together without some kind of firm surface mat on top of the carpet for the office chair. Plastic chair mats are only partially effective because the wheels sink into the plastic leaving little indentations to roll back into, and the plastic mats are unsightly in the home environment.
This project presents a simple low-cost way of making a floor mat that is not only easy for office chairs to roll on, but is also attractive and can be made to match the surrounding furniture.
The typical plastic floor mat has a 40-to 42-inch deep by XX inch wide area behind the desk for the chair to roll on, and a 12- to 14-inch tongue that fits under the desk for the feet to rest on.
Assemble the first two pieces of the interlocking flooring. Lay one piece of flooring face-up on a large table. Place a bead of wood glue on the matching lip of a second flooring piece. Interlock the two flooring pieces, then align the ends of the two flooring pieces carefully before pressing down to lock into place. (Note: The ends must be aligned to assure the cross pieces interlock correctly. Light tapping with a mallet can provide a fine adjustment.) Place a weight on the joint to hold the assembly flat for a few minutes until the glue begins to set and the joint stabilizes.
Repeat step one with additional pieces of flooring keeping the ends carefully aligned, until 6 pieces are assembled.
Using a saw, split one piece of laminate down the center lengthwise. The edge will be straightened and smoothed with a router later on in the project. To ensure the laminate did not splinter, I marked the back of the flooring and used a draw saw to do the cutting. When using a hand saw you may have place a wedge in the saw cut to keep the saw moving freely since the wood is under a lot of tension and may bind the saw after a few inches.
Assemble the two pieces onto the ends of the 6-piece assembly using glue and interlocking the pieces and the assembly together. Weigh the entire assembly down with a weight heavy enough to keep the assembly flat and let set until the glue dries.
Place the flooring assembly upside down on a flat surface. Using a straight guide, route the interlocking edges off of the sides of the assembly. Remove only enough material to remove the exposed interlocking edges. Use the router to trim the extending ends of the flooring pieces mounted on the ends of the flooring assembly. Trim the cut edges of the flooring pieces mounted on the ends of the assembly, removing a minimum amount of material.
Measure the width foot/knee space available under the desk Add 1-inch for clearance. This will be the width of the tongue of the floor mat. Mark off the tongue width on one end of the flooring assembly. Either center or offset the tongue depending on the type of desk it is being built for. If one end has a better appearance than the other choose the least attractive piece to go under the desk.
Measure the length of the plastic floor mat not including the tongue. Use this dimension to mark off the depth of the mat that will be under the office chair. Finish marking the pieces that will be removed.
Clamp a router guide to the assembly and using a router with an edging bit, remove the pieces marked for removal in step six. I used a framing square clamped to the flooring assembly to give straight square edges and a pleasing arc in the corner.
Apply Liquid Nails™ adhesive to the back of the flooring assembly. Stay far enough from the edges so the adhesive will not squeeze out of the joint when the plastic mat is pressed onto the glue.
Lay the plastic chair mat, carpet fingers up, onto the assembly. Align the side edges and the back edge of the mat with the flooring assembly. If the mat is too wide, some mat plastic may have to be trimmed later. For now center the mat side to side on the flooring. Weigh down the assembly and allow the adhesive to dry.
At this point the mat can be used as it is. It provides an attractive hard surface. You may want to add the optional molding around the edge to help keep the chair from rolling off the mat, and to protect your feet from the edges of the flooring if you like to walk around barefoot. Cut and miter the molding, and attach with Liquid Nails™ to the floor mat.