Anyone? :)

We got the pedestals for our FL. Floor is not on concrete; it is on a regular wood joist floor over the garage. The FL doesn't vibrate much, except when I have a large load and the weight distribution isn't perfect on the final spin. After a minute it "planes out" when it reaches max spin speed, and vibration ceases. The washer sits next to an outside wall. The foundation is the downstairs garage wall, and laundry room floor joist sits on the foundation.

The appliance store sales guy told me if I jump up and down on the floor and felt a 'trampoline' effect, we would vibration problems. Because our washer sits next to an outside wall and the foundation goes right up to the laundry room floor, it's not much of a problem. If your laundry area is over a load-bearing wall, you might not have much trouble. Newer home construction seems to have wall and floor joists farther apart (cheaper to build). I can't help but wonder if some of the FL vibration issues are because of that.

Our son and his wife are renting a condo that has a FL washer/dryer and no pedestals, on the first floor, outside wall right behind them. Very similar to my situation. I'm not sure what is under the floor (joists or concrete), but one night we were over there when a very large (gallon) jug of liquid detergent was vibrated right off the top of their washer, hit the floor and leaked all over the flooring. No pedestal.

It is probably impossible to predict without knowing how the home was constructed, space between floor joists, etc.
Perhaps your appliance dealer is willing to take the pedestals back if the vibration is too much?

Thank you for the response. This is definitely useful. I guess I'll wait to move in and then see if there are any vibration issues by doing the "trampoline" test. Even then, I'll probably run the washer and dryer a few times to get a baseline "vibration" check. Indeed, if I can return the pedestals at no cost, then it may be worth it to try.

The laundry is upstairs in our rent house. We put our w/d on their pedestals (which never walked on a cement slab) when we moved in, and they vibrate out of place every load. Every couple of weeks, my husband has to push them back in place about 6-8" so I can fit my baskets in front of them.

One more thing to consider, unfortunately I learned the hard way. We have a second floor laundry and there is a drain pan with a drain in the middle. under the washer. When the washer was installed it was impossible to pull out the drawer on the pedestal because of the lip on the drain pan. I am not willing to remove the drain pan so will have to be content with the storage in the pedestal under the dryer.