[nostatic]

Hi, we're building a house and I have an opportunity to pour 1.25" concrete floors instead of using regular or engineered I-joists. The house is three levels, with the HT going in the basement. So there would be a concrete pad separating the HT from the main floor above. Anyone else done this, and what effect does it have on reducing sound transmissions between floors? Even if you haven't done this, what do you think would be the effect?

 

[petew]

Sounds like the concrete will be poured over a conventional floor structure. 1.25" isn't thick enough to be structural on its own. Concrete is often poured over framed floors to contain radiant heat tubing - it that what's going on here?


Couldn't hurt with sound isolation, but once the sound gets to the structure, you're not going to stop it.

 

[J. L.]

I have a basement theater with a similar type of ceiling you are describing. In my case, the ceiling is constructed from plywood, wire lath, then about 1 1/2 inches of concrete serving as a bed for 3/8 inch thick quarry tile. In between the ceiling joists is fiberglass insulation. Below the ceiling joists in the theater is an acoustic suspended ceiling.


I hear lots more sound coming up the stairwell than through the floor. In fact, I can be immediately above the screen/speakers and still can hear more from the stairwell 20 feet away than through the floor.


My home is also three levels. My bedroom is on the upper level. I can barely hear the theater from the bedroom at normal listening levels. I cannot hear the bedroom TV from the theater at all.


I would say that if the expense was not too great, then go for it. It will lower the sound transmitted to the rest of the house.


J. L.