How to Build a Front Load Washer Pedestal on an Uneven Floor

Place two, 30-inch pieces of wood to each outer side of where the frame is to go on the floor. Set the 60-inch studs in the front and back to form a rectangle, measuring 36-by-60-inches at the outside corners. Place the sheet of plywood squarely on top of the studs.

Set the bubble level in the middle of the plywood to see which way the floor is unlevel. You will have to measure left to right and front to back to gain an understanding of the low area. For example, the bubble level may show the front left corner is off-level, with the bubble consistently dipping in that direction no matter where you move it on the plywood. Lift the left, front corner of the 30-inch stud slightly until the bubble reads level. If the bubble shows that the entire left side is lower than it should be, lift both ends of the 30-inch stud until the level reads correct.

Slide a thin piece of wood under the left side board to hold it steady and in place in the example. The left side board is now at the height that it needs to be nailed as part of the frame to hold the pedestal level across the top. The wood you slide under is a temporary "shim" or piece of material used to fill in a gap.

Remove the plywood, ensuring you don't disturb the shim holding the left end up to the correct height. Nail the outer rectangular frame together with two nails into each corner. The left end piece will be higher on one or both ends of the rest of the frame, depending on if only one corner or the entire side is being used.

Add the plywood back on top and nail it to the studs below every 18 inches along the outer edge. Flip the frame over so that the plywood is on the floor with the stud frame in the air.

Place the two remaining 30-inch studs equidistant in the frame, like rungs on a ladder. They should rest against the bottom of the plywood, which means that they will not quite be level with the bottom of the outer frame studs. This is okay, because when you flip the frame back into position you want the plywood to be setting directly on top of the inner rungs. Nail the inner rungs into place with two nails on each end through the side of the outer studs.

Flip the pedestal back onto its bottom and set into place. Check with the bubble level to ensure that it is reasonably level. Washer and dryers come with their own leveling system so if the pedestal is not perfect, any minor corrections can be done with the washer and dryer system.