Thump thump thump thump

May 23, 2006 2:31 PM

My downstairs neighbor won't tolerate the sound of my treadmill. Any ideas?

My girlfriend recently moved in with me, bringing her treadmill with her. One of the first times she used it we got a knock on the door from the downstairs neighbors to cut it out. What I need to know is, is there any effective way to minimize the noise of the running impacts on the treadmill?

I have hardwood floors that I'm sure are just perfect for transmitting the noise down to them.

I've checked this soundproofing thread but since I'm renting, changing the construction of the floor isn't an option. Places like soundproofing.org sell products, but I'm not ready to buy until I'm sure they're going to work.

Any ideas?

posted by davidnin to home & garden (17 comments total)

Put a padded rug under it. Find out when the neighbor isn't home, schedule runs during those times. Tell the neighbor ahead of time when she'll be running so he can put some music on or leave the house or at least know it will be over in x minutes. Run outside as much as possible.
posted by bonheur at 2:40 PM on May 23, 2006

Ask your neighbors if there's a usual time that they're guaranteed not to be at home, and adjust your schedule accordingly.
posted by hydrophonic at 2:40 PM on May 23, 2006

Maybe some of that non-slip, thick play surface stuff? I just saw some of it at Toys R Us the other day. The pieces fit together like a puzzle. I can't find any of it online, though, and I don't recall the brand name, but they were using it under one of those plastic play things to keep it put whilst kids crawled all over it. It seemed to dampen sound pretty well.

Theatres sometimes use a black 3M product to soundproof stages -- again, I'm coming up with a lot of chaff in my googling, but I would bet that a high-end stereo place could point you in the right direction.
posted by Medieval Maven at 2:47 PM on May 23, 2006

Yoga mat. Cut it up. Put several layers under the feet of your treadmill. No more vibration transmission.
posted by jellicle at 2:47 PM on May 23, 2006

Depending on the space you have you might consider a stall mat. They are basically 4' X 6' rubber mats that are 3/4 " thick. Their intended use is in horse stalls, but I used to work in an animal supply store and we had several customers who bought them for home gyms. In fact, my gym uses a product that looks very similar to what we sold. They do a nice job of absorbing impacts and are quite durable. The mats are generally are $40- $70. If you go to pick one up, bring a buddy because they are about 70-90 pounds and unweildy.

Even if you don't decide to go this way, I second or third the idea of talking to your neighbor about a time schedule.
posted by Macduff at 3:15 PM on May 23, 2006

I tried to solve a problem similar to this once. I was playing Dance Dance Revolution. I tried carpets and layers of foam and everything. Which damps the trebble but it's the low frequency stuff that travels anyway, and footsteps are pretty low frequency.

Basically I agree with the suggestions "coördinate your schedule with your neighbor"; a technological solution will be expensive and time consuming and probably won't even work all that well anyway.
posted by aubilenon at 3:31 PM on May 23, 2006

I agree, work with your neighbor. That would make both parties happy. I am VERY skeptical that any acoustic solution that would work sufficiently, especially since the people downstairs are obviously sensitive to the noise. I mean, come on, we're talking running impacts on hardwood.
posted by rolypolyman at 4:18 PM on May 23, 2006

For my front-loading washer, when I lived in a condo, I put down 1/2" closed-cell yellow foam (aka "backpacker's bed") and a sheet of 3/4" MDF on top of that. The neighbour claimed to never hear the washer, though I'm fairly convinced that's an outright lie. Still, it must have done some good.
posted by five fresh fish at 5:33 PM on May 23, 2006

You may want to try shifting the treadmill - and get feedback from the neighbors to see if any areas are quieter than others. We had upstairs neighbors that would do step aerobics - if it was on one side of the living room, all of our closet doors would swing open and closed - the other side of the living room was fine.
posted by blackkar at 7:04 PM on May 23, 2006

I want to commend you for caring about your downstair neighbors comfort. Really that's a wonderfu quality.

Many decades ago I had upstairs neighbors that would play ball with their dog, inside, in the middle of the night. They couldn't have cared less how it affected our life.
posted by LadyBonita at 7:13 PM on May 23, 2006

fff's closed-cell-foam-under-thick-MDF trick is the right approach. Your treadmill is currently coupled to the floor via its feet, which have a very small surface area. Because pressure is inversely proportional to area, the downward force of each foot impact causes substantial pressure waves to couple into the floor, causing noise for your neighbors.

A thick sheet of MDF under the whole treadmill makes for a vast reduction in pressure by spreading the impact load out over the whole sheet, making it feasible for the resilient foam underneath it to damp the now-much-smaller pressure waves.

Bigger, heavier rigid sheets on softer foam are better. Try a four foot by six foot sheet of 1" particleboard over a two-inch foam mattress.

Also, position the whole arrangement as close to a load-bearing wall as you can. You want to try to avoid turning your floor into anything resembling a trampoline.
posted by flabdablet at 8:16 PM on May 23, 2006

An inch or two of some damping material will do wonders for eliminating the drone of the treadmill motor. It won't do much at all for the thump, thump, thump of someone running. You would probably need more like a foot thick of a less dense damper to absorb all that energy without transmitting it to the floor as a thump. Coordinate schedules, run outside or be a bad neighbor, those are pretty much your choices without stiffening the floor or putting the treadmill on some sort of obscenely huge cushion.
posted by caddis at 8:54 PM on May 23, 2006

(A 4x6' x 1" MDF is going to weigh a metric ton. You will need a couple of Burly Men to shift it for you. Honest to god, it's 200lb if it's an ounce.

Caution on the "softer foam" meme: if you were using that crappy 2" expanded-foam stuff you had to sleep on when visiting Auntie Fugly on Memorial weekend, dropping both the 200lbs of MDF and another couple hundred pounds of treadmill and another couple hundred pounds of you... well, it won't be so much a cushioning foam as a smear of petroleum compounds.

Hence the need for closed-cell foam.
posted by five fresh fish at 9:05 PM on May 23, 2006

Under a flat sheet, I'd expect two inches of Auntie Fugly's foam to compress to about half an inch thick. Clearly I've just pulled the calculation out of my arse, but the reasoning is as follows:

You want the supporting sheet to be as massive as you can manage, to turn impact strikes into minimum deflections; and you want the mattress to be as thick and soft as possible, to best limit the coupling of those deflections to the floor underneath. On the other hand, you don't want it so soft and thick that your treadmill runner gets seasick. ISTM that Auntie Fugly's mattress should actually be about the right compromise.

If I'm on my back on such a mattress, I only hit bottom if I turn on my side; 2" of mattress foam is enough to keep 130kg of me well off the ground if I lie reasonably flat. I'm lumpier than the bottom of a sheet of MDF, but even assuming a flat flabdablet of uniform density, I occupy less than a third of the total surface area of a 6x4 mattress; the same mattress should therefore yield about the same maximum compression when supporting at least three times the load, when that load is distributed evenly over its whole area via a rigid flat sheet.

The way to tell for sure is to put a bathroom scale on top of a sample of foam, and load it until the foam compresses to about half an inch thick. Then divide the weight shown on the scale by the surface area of the bottom of the scale in square feet, and multiply the result by 24. That gives you the maximum static load you can reasonably support on a 6x4 slab of that kind of foam (including the weight of the MDF).

I'm tipping your 1/2" closed-cell foam sheet didn't compress much with your washer on top of it, even full of water. That stuff is really firm.
posted by flabdablet at 10:37 PM on May 23, 2006

There is at least one other sound proofing thread: How do I enjoy my new computer speakers without pissing off the downstairs neighbors?
posted by Chuckles at 12:02 AM on May 24, 2006

Just wanted to give some kudos to you for respecting yoru downstairs neighbours. My girlfriend is especially sensitive to noise, and our upstairs neighbours either have serious anger issues, or weigh 350 lbs, because all we hear all night long is "stomp stomp stomp stomp stomp". I'm not really sure that ANYTHING will suffice tor alleviating your neighbour's problem though - if they're anything like my girlfriend, even the slightest bit of thumping will still stir them into a rage.

When is your girlfriend getting on the treadmill? I presume it's not at 1:30 am, right? If you can't find something that works, and your neighbour decides to be a jerk about it (ie not trying to be helpful about schedules or anything), I say it then becomes a "Well, tough" situation. I'm not sure what the noise regulations are where you live, but if it's not sleepy-time, a little bit of thumping is hardly going to get the police interested for a "disturbing the peace" charge.
posted by antifuse at 3:02 AM on May 24, 2006

Obviously this depends on your building, but maybe you can find a place in your apartment that's not above your downstairs neighbor's living space. Or maybe there's a space in a lower level of your building (basment? laundry room?) where you could set up the treadmill.
posted by mbrubeck at 5:44 AM on May 24, 2006