Why not buy a stacking front loading washer/dryer. Won't have to build anything and will likeley work well. I Wouldn't worry too much about the floor. If 3 or 4 people can stand there and it doesn't collapse you'll likely be fine. Take a peek underneath at the structure though just to be sure.

i looked at the stacked washer/dryer one piece models. they are 27" wide if i recall. plus, if one dies...

thats why i'm trying to make a platform for stack the dryer separately, so that i won't have to worry if one breaks, don't need to buy the matching mate to keep it properly stacked.

Don't agree with the HD guy. I would still consider plan A if your wall studs are in good shape and positioned so the platform could be well supported. A dryer doesn't weigh as much as a washer and if properly setup should never generate the dynamic forces of a high speed washer. There are all sorts of building techniques for the dryer shelf that would be very sturdy. If you want to over build it, fasten 2x4's horizontally around the perimeter of the alcove bolted into the studs. Then build a shelf that sits on top. If you want even better strength for the shelf, put 2x4's edge wise going across the bottom of the shelf platform (the same idea as floor joist construction). The other construction method is to build something up from unistrut (there are lots of brands of this stuff) metal framework. They have all sorts of specialty pieces to make designs very flexible.

Companies like the Container Store sell wall shelf units that are designed to be supported by nothing more than very nice drywall anchors. Personally I like going into studs, but they say it's unnecessary. They will build up shelf systems that will hold up to 500 lbs with this technique. If drywall/blueboard can support this kind of weight, your studs should be able to handle the under 200lbs of a dryer plus shelf.

lilafter,

You did not mention whether the residence you are in is part of an Architectural Preservation program, therefor, limiting your building modifications? Anyway, Gordon is on the right track. If it were me, I would simply purchase some used warehouse shelving (it gets resold by many businesses buying liquidation goods); place the shelving atop the plywood to physically protect the floor beneath and be done with it. One word of advice, if you use a commercial shelving be sure to apply white grease to the studs that slip into the eyelets or it will be difficult to disassemble.

Warehouse Shelving Example

I have a Frigidaire (Kenmore 2003 FridGEmore) set stacked, in a small utility room (larger than yours, however) near the back door, on a wooden floor over a crawl space.

I do not have any special plywood layer on the floor. I don't have any problems with excessive vibrations. I'm not going to tell you that there are no vibrations or noises at all, but I don't have any banging, house falling down, (whatever other horror stories you have heard) vibrations.

My old Top Loader vibrated and made noises, and the FL is much quieter. The sounds the FL make are DIFFERENT than the sounds a TL makes. I often suspect that is why some new FL owners complain about FL vibration and noise: 1) They are paying close attention, now that they have this new-fangled washer. 2) Over the years, they became very accustomed to the sounds their TL made and just learned to "tune" them out. They probably haven't paid attention to the TL sounds and vibrations for years, and sort of forget that the TL does make noises and has it's own type of vibration issues.

Most importantly, make sure your Frigidaire FL is properly leveled. I know there are threads on this forum that give instructions on how to balance a FL. Some have recommended doing so while the FL is spinning, to get the best "attunement" as it were.

Your utility room floor is attached and stabilized by the nearby outer wall. If you can get into the crawl space, you can install additional supports under the floor by using something similar to the deck block below.

CMC

Here is a link that might be useful: Deck block with deck post adjuster

i've been doing more research- in australia, their dryers come with wall mounting kits! i think they might be smaller 9kg dryers(not sure how it converts to cubic...)but its comforting to know i'm not crazy!

gordonr-i'm thinking of doing a plan A/B. use heavy duty 18-20" L brackets to provide rear support-stud wall to plywood, 2x3 wood legs/post 28" width ( for 27" washer to slide between)38" high (in case i need to add a floor plywood base), legs come out 20" from the wall and use 10" L brackets to cantilever the front. attach legs to 2x3 base about 25-30" long from wall to front.

farhenheit 451- i did actually look into getting used wharehouse shelving! i was walking around HD and osh and thought those shelves would be great for this. but the ones i found on the internet are huge!

cmc 97- thanks for the deck block idea. i will check my hd and see if they have something like that. my soon to be laundry area is small but i think that might be helping the old floors feel solid- esp that one of the walls is an exterior wall. and FINALLY- one person with wood floors over a crawl space who isn't being shaken out! thank you, there just might be hope for me.

i came up with a plan C- wire shelving stand. its free standing, holds a bunch of weight. i have 3 at home now for storage. 30x30 is an odd size, but i did find one brand that makes it. throw a piece of plywood over to make a solid platform base and around the sides. watcha think? might work???