A flood can ruin your washer and dryer. Even just a few inches of water can cause major problems. As long as the flooding doesn't exceed 12 inches, the best solution for protecting your washer and dryer from a flood is to put them on a pedestal. While pedestals are available for purchase, they can be quite expensive. The cost is much less if you build your own.
Measure the length and width of your washer and dryer as they sit together. Ensure to take into account clearance between walls and the machines. This measurement will be the minimum about of space you need for your washer and dryer. You can make it bigger, if you have the space.
Cut two long sections of two-by-twelve lumber according the length measurement. Cut three shorter sections of the lumber according to the width measurement. Alternatively, use two-by-ten, two-by-eight or two-by-six lumber depending on the flooding you expect and the space you have above the washer and dryer.
Form a corner with a length and a width piece of the lumber. Attach corner clamps to secure the corner. Place one corner clamp at the top of board and another at the bottom. Ensure the corner angle is 90 degrees, using a T-square and level. Mark and drill three pilot holes for the 3-inch wood screws. The pilot hole diameter should be slightly smaller than the diameter of the wood screw. Repeat this process with the other length portion and one width portion of lumber.
Set the two L-shaped sides next to each other, forming the pedestal base. Clamp the two sides together with corner clamps at one corner. Ensure the corner angle is at 90 degrees. Mark and drill pilot holes, then drill in the wood screws. Repeat this step for the final corner to form the outside of the pedestal base.
Measure and mark the midpoints of both lengths of the pedestal base. Place the third width section you cut in Step 2 vertically at this midpoint. Use box clamps to hold the width section in place to form a joist. Ensure the top of the joist is even with the top of the outside of the pedestal base. Mark and drill three pilot holes on each side. Drill 3-inch wood screws into the pilot holes to secure the joist to the pedestal base.
Measure and mark the midpoints between the joist you created and both ends of the pedestal. Place the two final width sections you cut in Step 2 vertically at these midpoints. Ensure the top of the joists are even with the top of the outside of the pedestal base. Use box clamps to hold the joists in place. Drill pilot holes and secure the joists with 3-inch wood screws as you did for the center joist in Step 5. This completes the pedestal base.
Measure the width and length of the pedestal base and cut a the plywood to this measurement.
Place the plywood on top of the pedestal base. Mark and drill four pilot holes along both width ends; six pilot holes along each length of the pedestal. Remove the plywood top and set it aside.
Apply construction adhesive to the top of the pedestal base, including the joists. Avoid the pilot holes you drilled in Step 8. The construction adhesive is to keep squeaking to a minimum and to join the joists to the pedestal top.
Place the plywood onto the pedestal base. Drill the 1 1/2-inch wood screws into the pilot holes, securing the top to the base.
Place cinder blocks or sandbags on top of the pedestal and over the joists. Allow the adhesive to dry for 24 hours.
Apply a primer coat of paint to the wood before painting it your desired color.