Deadlifting In My Garage

[Giri Kotte]

A 3" thick platform of horse mats and MDF or plywood (as described in SS) along with bumper plates does sound like the best extreme measure that can be taken.

[Yonason Herschlag]

My wife was worried about me damaging a slab. I told her it was no worse than two fat guys jumping up and down.

No comparison. The fat dudes weight is spread out over the area of their shoes (four shoes has an area of about 120 sq/inch), whereas the bar contacts the floor over an area of about 2 sq/inch. These are just rough estimates.

Secondly, the fat boys have joints, soft bones, and other soft tissue to absorb the impact. Iron hits in one shock.

Assuming you're not dropping the weights, and assuming the floor construction has some iron reinforcement, if you have that mat and covered plates, there's no risk of property damage. But if your parents are old, they will nevertheless be disturbed by the vibrations and it will make them nervous. If you put more than one layer of soft floor covering you will lose stability in your stance - like wearing soft sneakers to lift. Ideally you could bring in a hard-wooden lifting platform. That increases the footprint hitting your parents garage floor from 2 sq/inch to over 5,000 sq/inch. That will totally diffuse the problem. If that's too expensive, put the hardest plywood you can get under your matting.

[Mark Rippetoe]

Ideally you could bring in a hard-wooden lifting platform. That increases the footprint hitting your parents garage floor from 2 sq/inch to over 5,000 sq/inch.

This is not true. It might be true of a structure that was so absolutely rigid that force transfer between the point-loaded side (the points directly under the plates) and the entire surface area of the structure in contact with the concrete was 100% efficient, and neither a plank-built platform nor a plywood platform are such structures. The force is in fact distributed across much more surface area than plates against rubber, and this is why I recommended a platform. But the force transfer is not perfectly uniform.

[Yonason Herschlag]

This is not true. It might be true of a structure that was so absolutely rigid that force transfer between the point-loaded side (the points directly under the plates) and the entire surface area of the structure in contact with the concrete was 100% efficient, and neither a plank-built platform nor a plywood platform are such structures. The force is in fact distributed across much more surface area than plates against rubber, and this is why I recommended a platform. But the force transfer is not perfectly uniform.

Rip, excuse me, but did you get enough sleep last night? This post is not up to par with your usual excellence in articulation.
1. We both agree that a platform is recommended.
2. We both agree that the platform will spread the force of impact over a much larger area.

So why confuse everyone by first responding to my post saying "This is not true."?
You agree with the recommendation. Your only criticism is the exaggeration of my mathematics. So if the math is not 2 sq/inch surface spread to 5,000 sq/inch because the platform won't spread the impact perfectly evenly, the basic idea I was presenting is that the impact is spread over a MUCH greater area. So if the area isn't 2,500 times greater as I (inaccurately) implied, it's still hundreds of times greater for sure.

I don't really care about being knocked or criticized, but your post will leave people confused about what is "not true" without this response and clarification.

[Mark Rippetoe]

Rip, excuse me, but did you get enough sleep last night? This post is not up to par with your usual excellence in articulation.
1. We both agree that a platform is recommended.
2. We both agree that the platform will spread the force of impact over a much larger area.

So why confuse everyone by first responding to my post saying "This is not true."?

Because it's not true. When you play the role of an expert, it is expected that your details are more than merely true-ish.

[Giri Kotte]

This is not true. It might be true of a structure that was so absolutely rigid that force transfer between the point-loaded side (the points directly under the plates) and the entire surface area of the structure in contact with the concrete was 100% efficient, and neither a plank-built platform nor a plywood platform are such structures. The force is in fact distributed across much more surface area than plates against rubber, and this is why I recommended a platform. But the force transfer is not perfectly uniform.

Agreed. Most of the cushioning is due to the damping characteristics of the platform rather than distribution of the pressure over a greater area. While a thicker piece of hard wood can distribute pressure more effectively, this assumes perfect surface to surface contact between floor and the plank, which never is the case, and the thickness needed might be impractical.

[Tony Moma]

Are they REALLY concerned about the foundation or is that just a cover because they hate the house shaking?

If they just hate the noise/vibration you might need to get more padding to appease them.

Two or three layers of yoga mat (or similar) under where the plates touch the ground will help somewhat. You'll then need a piece of shark tooth mat to stand on to even out the height. You could also play around with putting some yoga mat or camping pad under your rubber mats, though you obviously don't want it to feel at all squishy underfoot.

Thank you for the suggestions.

You can ask your folks when they plan on grocery shopping or do they have a night out? , to be fair it's their house and you probably should not do it during their down time, some people find the noise very stressful.

Point taken. It's their place, so their feelings should be given priority. Fortunately, they're getting used to it, and it helped that I was able to reassure them with the info gotten from this thread.

[Tony Moma]

No comparison. The fat dudes weight is spread out over the area of their shoes (four shoes has an area of about 120 sq/inch), whereas the bar contacts the floor over an area of about 2 sq/inch. These are just rough estimates.

Secondly, the fat boys have joints, soft bones, and other soft tissue to absorb the impact. Iron hits in one shock.

Assuming you're not dropping the weights, and assuming the floor construction has some iron reinforcement, if you have that mat and covered plates, there's no risk of property damage. But if your parents are old, they will nevertheless be disturbed by the vibrations and it will make them nervous. If you put more than one layer of soft floor covering you will lose stability in your stance - like wearing soft sneakers to lift. Ideally you could bring in a hard-wooden lifting platform. That increases the footprint hitting your parents garage floor from 2 sq/inch to over 5,000 sq/inch. That will totally diffuse the problem. If that's too expensive, put the hardest plywood you can get under your matting.

Excellent points, especially the one on the difference between iron hitting the ground and two fat males. Much appreciated.

[Giri Kotte]

What is the construction of the garage floor? Slab? Pier-and-beam? Over a basement?

I'm planning to set up a gym in the first floor of a residential apartment. I plan to use the SS recommended 3" plywood+horse mattress set up for the deadlift, along with using rubber coated plates, and deadlift in the balcony. Would that be adequate to keep the thump at bearable levels and the slab safe?

[Mark Rippetoe]

Depending on your building codes, yes.