Wood frame house and HE washing machine vibrations
HE washers are great for energy and water efficiency, but they vibrate more than the top-loaders.
For a wood-frame house (2×6 walls), what is the best way to minimize worry about vibration from front-loading washing machine (Miele W1753 if it matters).
The installation manual says :
A concrete floor is the most suitable installation surface for a washing machine, being far less prone to vibration during the spin cycle than wooden floorboards or a carpeted surface.
The machine must be level and securely positioned.
To avoid vibrations during spinning, the machine should not be installed on soft floor coverings
If installing on a wooden joist floor:
We recommend a plywood base (at least 59x52x3 cm). The base should span several joists and be bolted to the joists and not only to the floorboards. Check for the presence of pipes and cables first.
If possible, install the machine in a corner, as this is usually the most stable part of the floor.
Can one improve on it? The frame is up but the floors are not, so there is a chance to stregthen the area.
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Replies
For the sake of troubleshooting: did you remove the moving bolts?
Jamie
orange_cat,
Have you considered anti-vibration pads?
The reviews on anti-vibration pads seem mixed. I had the same machine installed over concrete and that was fine. But in a previous house stacked Bosch front load washer and dryer vibrated in such a way as make me wonder if they are making the house structurally unsound.
This laundry room is a new build, the frame is up and floor plywood, but nothing else yet, no insulation, nothing. So I have a chance to at least try to minimize the issue.
(It is a known problem - both from the manufacturer's instructions and from experience and google) but I have not stumbled upon structural solution to it.
I've dealt with this issue on many projects I have designed. Stacked units vibrate more than side-by-side units. Anti-vibration pads help but don't eliminate vibration. On a couple of projects the problem was so bad that the machines would jump off the pads; we drilled into those pads to help the machines' feet remain seated. Having a lot of mass in the floor system, and having the structure sized for modern codes, are both important. I try to talk clients out of having the laundry on upper floors, with varying success. I recently met with clients I designed a second-floor laundry room renovation for about 15 years ago and they ended up moving the laundry room back to the first floor because they couldn't fix the vibration problem.
"install the machine in a corner"
I think this is about the only thing that helps. If not in the corner, right by an outside wall.
I've dealt with front loaders and tried a bunch of things, and this is about the only thing that works. I also always install them over rubber pads, I use pieces of rubber stall matt stacked for this.
The rest help but don't make much difference. Tried adding mass (mud base with drain) and it doesn't do much. Maybe if you pour something much thicker, say 8" to 10" pad combined with rubber feet it would help.
The one that I though would work but it is not great is having the unit above the beam holding up the floor, the machine on spin cycle sounds like a helicopter flying overhead.
The one that definately does not work is anywhere in the middle of the floor that does not have a wall underneath. If this is your case, I would try to run a post down to the basement underneath the unit or if not possible, reinforce the joists by sistering LVLs on either side. The LVLs don't need to be supported at the ends as there is no extra weight, they are there only to reduce deflection. Even better than LVL, sister with something like 14 or 16 gauge steel floor joists.
The manufacturers are specifying a sturdy base not from the sound perspective, but to control an unbalanced load rotating at high speed during a spin. This means that any kind of pad under the device is likely going to make that worse, and as Michael mentions, may result in sympathetic vibrations and "bouncing off pads".
The way to deal with this (which is not really practical) is to sit the washer on a high mass, then isolate that mass from structure. A washer with a slightly unbalanced load at a high spin rate is a lot of energy to deal with! Akos' suggesting with a very heavy concrete pan, isolated, would likely work best...and you would have to have structure there to support it. Choosing a corner is a lot easier :-)
You're describing a tuned mass damper--someone needs to design one for this situation! https://en.wikipedia.org/wiki/Tuned_mass_damper
Isn't that what finally fixed the Hancock Tower in Boston?
Yes, and I believe that was the first time it had been used in a skyscraper, though I can't recall precisely.
(For those who don't know, the ±60-story Hancock Tower in Boston swayed excessively in the wind, and the glazed curtain wall was not designed to accommodate movement, so the glass panels were falling out, until they built a mechanical tuned-mass damper somewhere around 1/3 of the way up.)
Tuned mass damper is very different. This is something that needs to be engineered and if done wrong it can make the problem worse.
My suggestion was along the lines of #11. This is relatively easy to get right. Generally what you need is a slab a couple of times the weight of the equipment (3x is a good start) and an isolator sized for the expected frequency.
This last part is also pretty easy from static deflection of the isolator. You want this frequency to be bellow the equipment vibrations. In case of most washers, the spin cycle is about 1000rpm, so 17Hz.
Fn=3.13*sqrt(1/ StaticDeflection)
Solving for static deflection using 17Hz, we get 0.03". You want Fn bellow this so your isolators should deflect about 0.1" (~10Hz) which is doable with rubber pads.
I would only do this if there is no other option.
Now you all have scared me (the hancock tower sounds especially disturbing). It is definitely against exterior wall, but not in a true corner. I have three choices - see attached drawing, ignore the cabinet designations -
(1) 13 inches from a true corner (with chimney running through a true corner on the interior - woodstove chimney from the floor below) - by swapping washer and dryer on the drawing.
(2) the opposite corner - but it is only a second-floor partition, not a true corner, on the lower level it is one room no partitions. I can rotate the machine too to fit it deeper into the niche (that was the original idea)
(3) put it in a true corner and guide the chimney on the other side? The chimney is making a slight turn as it is to end up in a ture corner - because the woodstove below puts the chimney further away from the walls, but the installer is fine with a slight angle hidden in the ceiling/floor assembly).
It sounds as if I should not put the dryer on top regardless of the locations (I did come across some consumer report piece saying their engineers found in case of Bosch it added stability, but not in other cases and it did not agree with my personal experience. And that was when my stacked bosch - come to think of it - was in a true corner.
(This is a top floor, no attic, the ceiling slopes with the roof right above the machines starting at 6 feet or so from the floor, directly beneath is a living room with the woodstove, and directly beneath that is a garage - at grade).
#1 should work well enough.
Bill's suggestion bellow of extra blocking between the joists is a good one. I would also double up the studs in the exterior directly under the washer floor joists.
The usual way this kind of thing is handled in commerical buildings for things like big motors is to use a precast concrete pad with a steel frame mounted on spring-type vibration isolators. The spring type vibration isolators help to isolate vibration from the precast mass piece from the floor, and then the vibrating/noisy equipment is mounted to the precast mass piece. The mass of the precast concrete in the frame helps to damp vibrations, then the spring type vibration isolators help to limit the amount of vibration that is transmitted to the floor of the building. These systems work well, but they are very heavy.
Cork and rubber vibration isolators work best for higher frequency sounds, and not as well (compared to the spring type vibration isolators) for lower frequency sounds, which is probably what you're getting from the washing machine. The downside to the spring type vibration isolators is that they are rather large physically, and will add height to your washing machine.
I would try a few things here:
1- Put the washing machine in a corner if possible.
2- Put some some solid blocking between the floor joists in the area under the washing machine, tying 3+ joists together, and ideally also tying into a rim joist or other "framing piece connected to something else at a 90 degree angle". The goal is to make the assembly as rigid as possible to avoid resonances.
3- Use a large precast paver under the washing machine, then some rubber vibration isolators between that and the floor.
That's probably the best you can do without going over to something that will be physically large and not exactly pleasing from a visual standpoint.
Bill