concrete slab vs/ wood floor - pros and cons


Audiogoners, given the choice, with sound quality being a top priority, which choice is usually better?

I have been given the green light from my wife, bless her heart, to convert our stand-alone 1935-era garage into a dedicated music/theater room - woo hoo!! The fact that it's a separate structure will be ideal for playing loud movies whenever without bothering anyone in the house. The space is roughly 11.5 x 17' and I think it will make a terrific intimate theater. It's completely unfinished inside and has a sturdy stucco exterior. It's a very solid structure. However, the concrete floor has some large cracks lengthwise due to settling so it is pretty crowned in the middle. If I keep the concrete, I will need to build a floor over the slab and shim it quite a bit to level it out enough to install the underlayment. Headroom is limited as the walls are just over 7 feet, although the roofline peaks at just over 10' in the center, enough height to hang my projector.

If I removed the concrete, then I could dig down and build a normal floor over wood joists with a nice hollow space underneath. My house is built over a crawlspace with hardwood floors and I like the quality of bass and overall sound I get in our living room. The downside is that it would be more difficult to convert the garage back later to use for parking a car if we move. I was thinking it might be cool to design this type of floor and then have space below for insulation, wiring, etc. without sacrificing any height. Maybe the floor could even be designed as a sort of bass trap to help with the sound. Any thoughts? -thanks, -jz


john_z
The older concrete gets, the harder it gets -- and I mean jackhammer hard!! You have two problems: levelling, and (potential) moisture. So far, you haven't said if your garage floor ever gets damp or even floods. So is moisture a problem or not? If not (the garage is on high ground?) then you could just level the floor with a fine sand bed and sand-set pavers (brick, stone, terrazo, slate) to make a very beautiful floor, with a really nice oriental rug on top. And if it's cold where you live (where was that?) you could lay some radiant heating elements in the sand bed. The 7' wall height shouldn't be a problem if the roof ridge is at 10', but there are probably cross members at 7'. There is a solution for this too: knee braces at the walls and cross braces near the peak.
Home depot sells a sub floor board which is easy to install. It comes in 2'x2'sheets and could be leveled out for any irregularities in the floor it will give you a nice warm floor and it helps out with acoustics you can put any kind of flooring over it you want rug wood or easy to install laminate. it adds approximately, a inch to hight even after you add flooring this is the ideal thing to do for leveling comfort and acoustics.I have a article on acoustic property's if I can find it.each Pallet covers 70sq foot you wood need approximately, 3 link http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?jspStoreDir=hdus&catalogId=10053&productId=100388255&navFlow=3&keyword=sub+floor&langId=-1&searchRedirect=sub+floor&storeId=10051&endecaDataBean=com.homedepot.sa.el.wc.catalog.beans.EndecaDataBean%4059912410&ddkey=Search OVRX 35 Pk. 2 Ft x 2 Ft Sanded OSB Insulated Sub Flooring Tile

Model H2424OVRX

$279.65/Pallet
John, Garages have been built the same way for a very long time, with a floating slab. This means that, yes you can tear out the old slab and the stem walls will remain. Forever... Ever wonder why the floor is cracked and not the stems? Two different pours. My guess (not really) is that the garage was first built with a dirt floor. That is how it was done in '35. The conc floor was probably "homeowner" done in the recent past. Tear it up. It will likely be simple cause it was done on the cheap, and is not 4 inches thick, nor does it have any baserock. Or rebar. Dig down another 4 inches, compact A/B, then barrier that, throw a little steel in there, run some conduit for your surround wires/cables and you have a floor that will increase resale value. Hang 5/8 board on the walls and you will realize how bad the bass is that you think you like now. Your Welcome. Z
John, tell Z you'd like to pay him to "tear out" the old slab for you. The laughs alone will justify the cost!! Just remember to invite us ;-) The driveway and garage floor of my little 1928 house in Hollywood, was poured at the time of construction, and jackhammering it out would have brought down the garage as well as the house, ha, ha!!
John, Tell NS to input only if he has some clue about the topic. Yes, the driveway and garage floor (in HW) were done at the same time, AS I describe. NOT the foundation. I will be bringing a wet saw, so there won't be too many laughs, just a VERY RED face! How about if the structure remains standing, NSGump pays? Two hours with the saw, two more with the Bobcat. Can MR. 837 answers afford that? John, please consider the source here, ever see anyone else with speakers four feet apart, who knew what they were talking about? ha,ha!! Z.