DIY Rough Framing for Bifold Doors

Determine the rough-in measurements for the doors. The simplest and most reliable method for doing this is to check the product packaging or documentation from the manufacturer. If this isn't available, you can employ typical framing standards by adding 2 inches to the height and width of the opening. For example, a bifold door for a 48-inch by 80-inch opening requires a rough-in frame of 50 inches by 82 inches. This allows for the addition of 3/4-inch finish lumber around the sides and top, as well as clearance at the bottom.

Cut the bottom plate of the stud wall to match the width of the opening. If you're remodeling, cut the plate with a reciprocating saw. If it's new construction, plan your cuts ahead of time and cut the plate to length with a circular saw.

Cut vertical studs from 2-by-4 lumber to match the distance between the top and bottom plates of the wall and place them 1 1/2 inches on either side of the opening in the bottom plate. Check the plumb of the studs and measure between the studs at the top and bottom to see they're the same distance apart -- this will ensure your rough-in opening is square. Toe nail the studs into the top and bottom plates with 10d nails.

Cut two jack studs from 2-by-4 lumber to match the opening height, less 1 1/2 inches. Place the bottoms of the jack studs even with the edges of the bottom plate and nail the jack studs to the studs you placed in the previous step.

Cut two header boards from 2-by-4 lumber to match the opening width, plus 3 inches. Nail the headers together to form a double thickness and place the headers on top of the jack studs. Toe nail the headers into the jack studs and the studs on either side of the ends of the headers.

Measure the distance between the top of the headers and the bottom of the top plate. Cut cripples from pieces of 2-by-4 lumber to match the distance. Place the cripples between the header and the top plate and toe nail in. Put one cripple on each end of the header and one header for each 16 inches of header distance, rounding up for the number of cripples and spacing them evenly across the distance of the header.