# Best mat/foundation for shock/impact absorption **URL:** \ **Category:** Factual Questions\ **Created:** [April 28, 2006, 3:24pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602 "2006-04-28T15:24:54Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![dre2xl](https://avatars.discourse-cdn.com/v4/letter/d/34f0e0/32.png) [@dre2xl](https://boards.straightdope.com/u/dre2xl)\ **Post date:** [April 28, 2006, 3:24pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/1 "2006-04-28T15:24:54Z")
I have a treadmill that I’d like to make a bit quieter for my neighbor downstairs. I’d like to know the most effective way to quiet the impact/shock from the treadmill, on a budget of, say, 200-300. I’m thinking of a sheet of 1/2"-3/4" plywood combined with insulation form of some kind. Perhaps even something like: 1. Layer of insulation such as this: [http://www.amazon.com/gp/product/B0009O9KBC](http://www.amazon.com/gp/product/B0009O9KBC) 2. Plywood 3. A regular ol’ treadmill mat on top of plywood What I’m confused about is which kind of insulation to use, and what order to lay the layers in. Any suggestions for what would be the best insulation/plywood, or is my thinking completely wrong on this? Also, would drilling triangular blocks on the foundation at the wheels help absorb impact at all? ---
**Author:** ![UncleBeer](https://avatars.discourse-cdn.com/v4/letter/u/977dab/32.png) [@UncleBeer](https://boards.straightdope.com/u/UncleBeer)\ **Post date:** [April 28, 2006, 4:37pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/2 "2006-04-28T16:37:23Z")
I’m a little confused. Do you want a sound deadener, or a shock absorber? Either way, you might wanna take a look at [www.sorbothane.com](http://www.sorbothane.com) ---
**Author:** ![dre2xl](https://avatars.discourse-cdn.com/v4/letter/d/34f0e0/32.png) [@dre2xl](https://boards.straightdope.com/u/dre2xl)\ **Post date:** [April 28, 2006, 4:51pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/3 "2006-04-28T16:51:51Z")
Sound deadener. My apologies, I tend to see the two as virtually the same. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 28, 2006, 4:56pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/4 "2006-04-28T16:56:13Z")
> [@dre2xl](#): > > I have a treadmill that I’d like to make a bit quieter for my neighbor downstairs. Any sort of foam, even styrofoam, will help with thru air sound, but it sounds like your problem is with motor vibration etc. being transmitted through the device and into the floor. I’ve built a number of devices with ~1/4 horse high speed motors, and found [closed cell foam of the type used by backpackers as sleeping pads](http://www.amazon.com/gp/product/B0000AUSM2/ref=nosim/102-8637772-0692925?n=3375251#moreAboutThisProduct) ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 28, 2006, 5:02pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/5 "2006-04-28T17:02:41Z")
-Oh good, I hit ‘reply’ instead of ‘preview.’ :smack: Any sort of foam, even styrofoam, will help with thru air sound, but it sounds like your problem is with motor vibration etc. being transmitted through the device and into the floor. I’ve built a number of devices with ~1/4 horse high speed motors, and found [closed cell foam of the type used by backpackers as sleeping pads](http://www.amazon.com/gp/product/B0000AUSM2/ref=nosim/102-8637772-0692925?n=3375251#moreAboutThisProduct) to be effective at deadening transmitted vibrations. Your treadmill likely puts out more low frequencies than my app, but the foam does work for stuff down below 60 cycles. I’d go with a layer of foam, a chunk of plywood, and another foam layer on top. With 3/4 inch plywood, that’d make the whole pad less than two inches thick. ---
**Author:** ![dre2xl](https://avatars.discourse-cdn.com/v4/letter/d/34f0e0/32.png) [@dre2xl](https://boards.straightdope.com/u/dre2xl)\ **Post date:** [April 28, 2006, 5:39pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/6 "2006-04-28T17:39:15Z")
That’s exactly the advice I was looking for **Squink**. And, yes, his main complaint is vibrations though he complains about the sound too, which is why I mixed shock absorption with soundproofing in my OP. Stupid question, though… wouldn’t the weight of the treadmill squish the closed-cell foam to virtually nothing? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 28, 2006, 6:10pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/7 "2006-04-28T18:10:16Z")
> [@dre2xl](#): > > Stupid question, though… wouldn’t the weight of the treadmill squish the closed-cell foam to virtually nothing? That’s why I go with closed cell. It will compress some, but the weight’ll be distributed pretty evenly under the plywood. The piece on top will get dents where the treadmill sets down, but won’t squish to nothing unless your treadmill’s on pointy feet. -If it’s got feet of any kind, you might want to consider modifying them to increase rheir surface area ---
**Author:** ![dre2xl](https://avatars.discourse-cdn.com/v4/letter/d/34f0e0/32.png) [@dre2xl](https://boards.straightdope.com/u/dre2xl)\ **Post date:** [April 28, 2006, 6:30pm UTC](https://boards.straightdope.com/t/best-mat-foundation-for-shock-impact-absorption/354602/8 "2006-04-28T18:30:25Z")
Makes fine sense. So, two layers of closed-cell foam sandwiching 3/4" plywood block. My treadmill is on 4 wheels/points, so I’ll break up my pre-existing mat ( [http://www.amazon.com/gp/product/B00076SPZO](http://www.amazon.com/gp/product/B00076SPZO) ) and place a square undereath each wheel. Thanks!