Recent reports indicate that High Efficiency Washer and Dryers are not a good fit for installation on anything other than concrete floors, meaning that they can't be installed anywhere other than a garage or basement (or on the first floor of a slab-built home.) Manufacturers simply say that they need to be installed ona "solid, level" floor. Unfortunately, the level of vibration given off by these types of machines in spin cycles shakes homes and has even cracked walls.

We'd like to build our next home, so this gives us an opportunity to try to an innovative solution to be able to install our beloved HE Washer and Dryer in a second floor laundry room.

Does anyone have any insights as to how to go about reinforcing a laundry room floor on the second floor to ensure that it (and the rest of the house) can withstand a HE Washer spin cycle?