How to Build a Frame for a Vinyl Window

Measure the height of the rough window opening in your home using a tape measure. This is the length required for the sides of the frame that you need to build.

Lay one 2-by-4-by-96-inch board flat on a work surface. Measure and mark the board to the length that you measured in Step 1 using a tape measure and pencil. Mark the board for two sides.

Place the marked 2-by-4-by-96-inch board flat on a radial arm saw and cut the board at the two pencil markings. The two cut lengths of boards are the sides for the frame.

Insert the two frame sides into the window opening so that they are parallel to the sides of the opening. Space the inside of the frame sides apart to the distance for the rough opening that is required by the vinyl window using a tape measure.

Hammer 8-penny nails through the top and bottom ends of the frame sides into the framing boards of the house at a 45-degree angle. This is called toe-nailing. Use two evenly spaced nails per joint.

Measure the distance between the inside edges of the frame sides. This is the length required for the top and bottom boards of the frame. Measure, mark and cut the boards to length from a 2-by-4-by-96-inch board using a tape measure, pencil and radial arm saw.

Insert the top and bottom boards between the frame sides. Position the top board between the top ends of the side frame boards and the bottom board between the bottom ends of the side frame boards. Space the inside edges of the top and bottom boards to the height of the rough opening required on the vinyl window packaging. Toe-nail the top and bottom boards to the side frame boards in the same manner that you secured the side frame boards in place.