Sound Control on a Budget
Good article and information for those planning to build a recording studio, or new home on a big budget.
A little more down to earth however, are questions concerning sound control in a 25 year old home that is undergoing a renovation, including the addition of a self contained basement suite. In this case (as in most) it boils down to a matter of compromise in terms of both construction limitations and budget. Following is a brief outline of some of the steps I took during this project to minimize the effects of sound transfer between the main house and suite:
Sound control played a major part in this project from its outset, realizing that when it was all said and done, someone would be living in the room next to my new home theater. The first step therefore, was to layout the space in such a way as to separate the suite from the main house as much as possible. This was accomplished by placing book shelves, closets, and other ancillary spaces on common main walls, which help form a buffer zone between living areas. Since I utilize electric zone heating, HVAC duct work was not a concern, but all electrical boxes were separated on common walls (as suggested in the article). I believe the most effective aspect of my sound control strategy was the construction of staggered stud walls, which form a space between the finished surfaces (as shown in the article). Unfortunately, budget constraints did not allow the installation of multiple layers of wall board to the studs. All walls (and ceilings) were well insulated with fiberglass bats, which I don't believe add a great deal of sound control, but do increase mass and are easy to install. A point about fastening drywall to the studs: make sure you use lots of screws or the board between the screws will vibrate against the surface of the stud, thereby increasing sound transfer (a bead of glue doesn't hurt either).
Another big concern of course is noise transfer through the floor, primarily from people walking overhead. This impact generated noise can be a real drag for the people living below, especially when the floor surface is hard, like tile or wood. In my case I was unable to use a hanging system for the finished ceiling (there's that budget thing again), but new I would be installing a new wood floor upstairs, so began to look at insulating the space between the sub-floor and the new floor surface. There are several products on the market which serve this purpose quite well. The best of these are sheets of recycled rubber, which are rolled out on the sub-floor prior to installation of the new surface. The products are rated according to Impact Insulation Class (IIC) and are commonly used in apartments and condominiums. The key to this system in wood frame construction is to install a floating product on top of the rubber "underlay" so that there are no nails to act as a source of sound transfer into the sub-floor and joists.
All and all I believe the steps taken have certainly helped. I can't here the guy snoring in the next room, for example. Having said that, I'm sure he can here my sub, which is the reason I no longer keep it cranked all night long and another one of those compromises I was talking about.
