FINISHED IN 2020! Sharward's Partial Garage Conversion

Thanks so much for your followthrough, Steve. :mrgreen:

Unconfirmed but believed to be reliable: My existing garage concrete floor is 6" thick (and possibly up to 8" thick around the edges), and it is reinforced with rebar. That is what the company has been doing for at least the past year for my builder. I'm awaiting a callback from one of their managers who has been with the company longer and can hopefully confirm this. If all of this is true, that's very encouraging -- right?

Yup - scenario #1 - you park a car that weighs 4000 lbs in that space; each tire has an approximate contact surface with the concrete of 6x8 inches, or 48 sq in. - each tire supports 1000 lbs, so at that particular location you have 20.8 PSI on the slab. Even a 4" slab won't break under those conditions. Scenario #2 - you place an 11,000 pound slab on RIM's over your existing slab; if your particular RIM system has 2" square pucks on 24" centers, and your slab is 10 x 16, you would have that weight supported by a total of 4x6x9 sq in, or 216 sq in, for a psi rating of 11000/216, or 51 PSI. Scenario #3 - same as #2 except pucks on 12" centers - now divide 11000 by (11x17x4), which gives 14.7 PSI. Granted the total weight of slab is about 3x what a car weighs, so this will obviously not be "apples to apples", but with your thicker reinforced slab it should all be a moot point anyway. I'll be finding out more about options with the Kinetics stuff in a couple of days... Steve

Yeah, but that's just the weight of the slab -- there's also those pesky walls and ceiling to consider! :shock: Any thoughts on using QuietWood Serenity atop Kinetics RIM Floating Wood Floor product? Totally inferior on low end TL? Any idea of the crazy-ass cost of that thing?

Yeah, stuff is somewhere around $200 a sheet IIRC - makes concrete look cheap by comparison, and concrete will blow its ass away (somebody should) You want to drum, stick with concrete - whatever flooring you put on top of it, you NEED that mass... Steve

knightfly wrote:

You want to drum, stick with concrete - whatever flooring you put on top of it, you NEED that mass... Steve

I'm just trying to establish a "Plan B" if case it is decided that concrete is impossible. The walls and ceiling are about 4 tons, and according to your calcs, a 6" floating concrete floor is about 5.5 tons. That's about 19,000 pounds over a 9x14"* area, or about 150 pounds per square foot -- and we know that the weight will be concentrated on the RIM blocks. Plus, that's an :shock: empty :shock: room -- put a few guys in it with instruments and furnishings, and we're looking at adding another ton or more. I figured the QuietWood Serenity stuff was probably at least that much. Bottom line, realizing that concrete is superior but comes at a cost of weight, if I can't afford the weight, then I'm willing to afford the QuietWood. I guess we can consider crossing that bridge if we run into problems supporting the concrete. *I'm figuring 9x14 because of the 5x4 chunk I had to remove from the space due to the landing requirements. Outer dimensions are roughtly 12-9-16-4-4-5.)

ya keith, thats the acheivable theory now your protected. My problem is I think(dont know) my slab is thinner,older, and probably no rebarb(?). I have to consider this myself. the wood floor by kenetics alone is like 60 stc, with the pricey quiet wood "should be better". Isnt that enough? isnt it like 60 stc for 100dbA? My question is how close is this. If I(we) cant acheive ultimate isolation(concrete) is this acceptable? What about the 3 1/2 " slab kenetics mentions on 2 models. Is this significantly lighter and how will it work?

All great observations and questions, Mike. I'm interested in the answers too. However, understand what STC actually means. It's an interesting number, but must not be relied upon in the context of what you and I are planning to do. To paraphrase Steve, forget about STC -- worry about low end TL, and mid and high end TL takes care of itself. Stop bass from getting out, and you'll take care of treble at the same time.

I spoke with a neighbor two doors down (the retired gentleman with the wood shop in his garage) about his concrete floor. His floor was defective and a portion of it had to be replaced within the past couple of years. He said his garage floor has no rebar and is at best 4" thick atop a layer of sand. I spoke with the concrete company about this, and they're going to call me back with (hopefully) more information tomorrow morning. Get me off this rollercoaster -- I think I'm gonna hurl. :cry:

I just had a discussion with dan hornac from tempco(kinetics). I dont know if hes was trying to buy a new pair of "new balances" on my dime, but hes recomended the RIM and was quite at ease with the weight factors. Im not gettin excited yet, but at least he was optomistic. It just seems wierd that every body here is so cautios and thorough yet the product saleman isnt worried at all. He wasnt worried about leveling(as long as not too drastic) or weight factors. That $12 a square foot can be up to $25 a square foot depending on the quantity bought. If we are both going to use this alternative maybe we should buy together, and anyone else whos in the market right now. GOOD LUCK..or maybe we should just get into kroket or watching nascar. Ive read the budwiser label long ago and feel really confident with my expertise in that world....

mikeklooster wrote:

If we are both going to use this alternative maybe we should buy together, and anyone else whos in the market right now.

I agree -- in fact, this is an area where our Northern California Gang of Studio Construction Wannabes might be beneficial -- perhaps we could co-op some of our purchases. :-) So, here's the latest on my existing garage floor situation. Today I spoke with a very knowledgeable manager at the concrete company that did the concrete work in my house. He said that his recollection of my subdivision is that they used 4" thick concrete atop a (minimum) 2" rock base with a 6" x 6" wire mesh for the initial phases (which includes my house), but that later phases may have upgraded to rebar. He siad the mix was designed at 3,000 psi, but that over time my floor hardened to at least 5,000 psi. He also said that he would not recommend more than 10,000 pounds of total weight for my room without consulting a geotechnical engineer. (Obviously, with 6,000 pounds of walls of 2,000 pounds of ceiling, an 11,000 floating floor won't fly on his word alone.) I called one of the geotechnical engineering companies he recommended. That gentleman said a 3,000 psi mix is "pretty darn good" because most are 2,500. He estimates that my concrete floor can withstand up to 250 psf. Bear in mind that this means, but recommended that I consult the structural engineer who worked on my subdivision. I called the builder and obtained the name and phone number of the structural engineer. I just left voice mail over there. So, let's do the math on what we know so far: Multiplying 250 (the psf estimate) by the square footage of the footprint of my floating floor (roughly 9' x 15') is 33,750. That's good. However, that would assume 100% contact between the floating floor and the existing concrete, which is not correct -- the RIM system has 2" square pucks on 24" centers. That means there is only 1 square inch of contact for each square foot of floating floor. That's the equivalent of about 126 square inches of weight transfer area, scattered around. Hopefully I'll get my voice mail returned with some assurances that I'm looking for -- or, I'll learn that this thing is just way too heavy for my existing floor. Or, perhaps a steel plate lying underneath the RIM system will help distribute the weight of the blocks over the concrete floor... But that may be problematic from an acoustical standpoint.

mikeklooster wrote:

dan hornac from tempco(kinetics). . . was quite at ease with the weight factors. . . It just seems wierd that every body here is so cautios and thorough yet the product saleman isnt worried at all.

Well, I just got off the phone with him. We spoke for over 20 minutes. He said he didn't know much about construction and engineering and that "you'll have to consult with your building and engineering experts" regarding the weight limits of my existing floor. Perhaps he misunderstood your "weight factor" concerns, thinking the concern was overloading the Kinetics product, rather than overloading your existing concrete. :?: I found this interesting tidbit:

Portland Cement Association wrote:

What is 3,000 pound concrete? It is concrete that is strong enough to carry a compressive stress of 3,000 psi (20.7 MPa) at 28 days. Concrete may be specified at other strengths as well. Conventional concrete has strengths of 7,000 psi or less; concrete with strengths between 7,000 and 14,500 psi is considered high-strength concrete. (Source)

I just posted at Eng-Tips Forums -- hopefully I won't get tarred and feathered for crashing their party! :shock:

I'll say this Kieth. Ain't no one gonna pull the wool over your eyes. :lol: Hope it turns out ok. fitZ

1/2" steel plate to cover 10 x 16 would weigh 2887 pounds, at roughly $1 per pound - acoustic problems, assuming full contact with the floorl, would be nonexistent afaik... Steve (course, your BRA would want to see a fire rating document on steel...)

cadesignr wrote:

I'll say this Kieth. Ain't no one gonna pull the wool over your eyes. :lol: Hope it turns out ok.

Thanks, Fitz... I owe all this latest grief to you for sharing your "cracked slab" experience... ;-) ...but I'll owe you big-time gratitude when I'm done with my room and my slab is still in one piece! 8)

knightfly wrote:

. . . 2887 pounds, at roughly $1 per pound . . .

:shock: Jumpin' Jehosephats! :shock:

. . . acoustic problems, assuming full contact with the floor, would be nonexistent afaik.

And that would be a challenge, due to the slope and some minor peaks and valleys. Hey, I got my first response to my thread on the Eng-Tips Forum:

A civil/environmental engineer wrote:

I would have a local structural engineer look at what you are doing, because some of these loads do get high. However, for the floor, you have a distbuted load of 140 psf (which includes a 50 psf liveload)assuming you can fairly uniformly distribut the load. The walls carry an additional 300 plf. With the proper details, you should be able to transfer the load to the the floor. However, again I would run it by a local engineer

Construction on this thing will not begin anytime soon. :?

At least you don't have to supply an environmental "impact" study.....wait a minute...wow, I guess thats what this is :shock: :lol: fitZ

. . . acoustic problems, assuming full contact with the floor, would be nonexistent afaik.

Hey, I read this last night, and I dont understand what "afaik" is supposed to be. Aint tryin to be anal but I cant see what that might be a misspelling for or abrev. for. I think your sayin metal plate bad, or is it acoustic problems would ba nonexisitant?

haha ... no it's not some arcane acoustical term or variety of insulation ... it just means "as far as i know" :lol:

AH! Internet lingo. I also just learned lol is lots of laughs not love. Thank you....So metal plate is good? sincerely, dumb ass mike

OMG...TWO Fitzpatricks here?.... :lol: Hello Dan, Rick Fitzpatrick here..otherwise known as fitZ. My screenname is cadesignr, which is my trade. I do CAD work. Anyway, nice to meet you. fitZ sorry Keith.

haha! we are taking over! :twisted: my dad goes by fitz too, nobody can ever get his given name right (kieran) nice to meet you too rick, i've enjoyed reading your posts dan

mikeklooster wrote:

I also just learned lol is lots of laughs not love.

Good grief, Mike -- who's teaching you Internetese, anyway? LOL = Laughing Out Loud :lol:

So metal plate is good?

Not at over a ton at $1 per pound it ain't! :?

fitZ wrote:

sorry Keith.

Geez, Rick -- First you freak me out about cracking slabs, now this? :? I'll consider forgiving you over the weekend. ;-)

Mike wrote:

dumb ass mike

Cool -- some variety! It's nice to mix in some "Dumb Ass Mike" with the "Smart Ass Mike" you've been giving us from day one, dude! :lol: :lol: :lol: IT MUST BE FRIDAY! ;-)

Mike, if you find a mis-spelling in my posts let me know; I have this thing about writing exactly what I mean (don't always accomplish it, but would like to) Here's a helper for your SIASS's http://members.aol.com/nigthomas/alphabet.html (Just in case you were wondering, that's NOT one of the standard ones - it stands for Stupid Internet Acronym Study Session ) 8)

Please don't shoot me for asking this. :roll:

Back in January, in his first response to this thread, knightfly wrote:

. . . the inner will need to be floated on the inner walls, which need to be resting on a floated floor. . . be prepared to put some $$$ into this part - for your requirements, I wouldn't recommend anything less than 3-1/2" of CONCRETE floated on PT 2x6's over EPDM pucks - you need lots of mass, a wide air gap, and high density rockwool fill under the floor if you're to kill things enough to not alienate the neighbors.

After weeks of challenges that all relate to having a floating floor in my design, I'd like to reevaluate this requirement. With thousands of views on this thread already, I'm sure many others wonder the same thing. Suppose I don't float a floor. Suppose I didn't even attempt to float the walls. Supose everything is permanently affixed to my existing garage floor slab. Bear in mind that the entire perimeter of my garage floor has a wooden "expansion joint" where it meets the footing of the outside wall or the slab on the inhabitable areas of the house. Perhaps that offers some independence from the rest of the structure and the world...? Also, the soil in my area is heavy clay, if that is a factor. I understand that floating 4-6" of concrete is ideal. However, what I need to establish with certainty is whether or not it is necssary to achieve the isolation levels I need. Regardless, I still plan for my air gap to be 11 3/4" along the walls (deeper between the doors) and at least 10" with 2.5pcf Roxul or Thermafiber (whichever I can get my hands on) between the leaves. I hope everyone understands that I'm not trying to ignore physics here. I just need to understand with as much detail and practical insights as possible how important the floating floor is in my design. This thing is in so much flux right now that I'm not sure whether or not I can afford to float the floor. What I would like to establish now is whether or not I can afford not to, and if I don't, whether or not there is anything else I might be able to do to mitigate the effect of going that route. Perhaps in lieu of a floated floor, I can consider doing what Andrew McMaster did as he described in this thread:

Andrew wrote:

My building is all one slab - there is no floor isolation, but my drums are on a riser filled with sand floated off the floor on neoprene pucks. The sound proofing is close to perfect - you cannot hear anything outside when inside the volume is as loud as you can possibly get it.

...Then I could get some use out of that EPDM I purchased...? Thanks in advance for settling this nagging dilemma in my mind (and in the minds of family members and friends who are watching me tear my hair out).

You wouldn't be "caving" on the "permits for everything" stance, would you? :wink: First, let me say that I've only a GENERAL idea of what each decision you mention will do to/for you - your original intent was that your neighbors weren't annoyed (or even aware) that you were playing drums at any hour - so I went with the optimum isolation for each case, within your space constraints. Had this been a "from scratch" project, I would have recommended even wider gaps between walls, with everything else being similar to my other recommendations; this is construction I KNOW will work. When you eliminate decoupling between inner and outer structure, you get flanking; this is such a difficult thing to figure that it's been known to make only a few dB of difference, up to sounding like the offending noise is being generated in the SAME ROOM - only safe way here is to decouple IMO. As to doing a riser, that will work for impact and coupled sound directly from the kit to the floor; however, if the rest of the room is NOT also similarly floated, the airborne sound will transmit thru the un-floated section of floor and into structure. If you built your riser large enough so at least the bass amp also sits on it, that would help. Guitar amps could be set on MoPads or similar for a few dB improvement in isolation. Your perimeter expansion joint, being of wood, will likely attenuate sound between slab and stemwalls/frame, but not STOP it; wood is nearly as good as concrete at transmitting sound thru shear waves, just at a different speed - for example http://www.uk-piano.org/sound.html Note the speed of sound in wood has Three different values, depending on direction - across the grain is around 4300 fps for Fir, discounting the possibility of travel ALONG the rings. Concrete - average sound velocity in concrete is around 4,000 meters per second, or around 13,000 feet per second compared to sound in air at around 1130 feet per second; So, sound traveling thru concrete/fir/concrete would experience two speed changes (and be diffracted twice) - this entire process would attenuate sound somewhat, but I'm not engineer enough to be more specific than that. Bottom line - not floating your inner walls (I think) would be a mistake - I don't have the capability of specifying the way to do that, independent of being set on a floated floor - maybe Kinetics has standard ways/materials for this, seems like I saw something. Possibly build walls/ceiling floated, then test, then add a floated floor of some kind if/when it's not adequate. If your walls are done first, you can always build an inner, floated floor later if it's not good enough; it's just not as easy as building from the inside out, things are harder to maneuver when there are already walls in the way... Steve

Hello Keith, well, I thought about it and this is what I would do, cause I could do it myself, and do a little at a time. This drawing is NOT exactly right, but it will illustrate the idea. What it doesn't show is the sand. I would sand fill a floating floor on piers. Cut away squares in your slab and pour them yourself. Hell with it. Anyway, just an idea. For me, this would work if I had no other alternative. Well, don't laugh to much, like I said, it wasn't finished as the wife was looking over my shoulder wondering when I was going to get busy on her "honey do's" :lol: Later. fitZ