Soundproof your garage or workshop

And in a way it makes sense: the more mass, the more noise blockage; therefore, rock wool is better at capturing sound because it’s dense.

Goyda disagrees: “For the longest time, people thought if you have a very dense batt-a 21/2-lb. density batt versus a 1-lb. density batt–that you’d have better noise control. That’s a myth. The National Research Council and Canada Mortgage and Housing Corporation did a study that showed there’s no difference between glass batts and rock-wool batts. I’d love to tell you fibreglass is better, but they’re equal–it’s the system that matters.”

Channel changer

Whether you use regular fibreglass insulation or special acoustical insulation there’s another key item for taking the edge off of sound: sheet-metal strips called resilient channel that keep drywall off of wall studs and ceiling joists. When sound hits a solid surface, such as drywall, it sets the wall vibrating, which in turn vibrates the drywall fastener and the stud, all the way through to the rest of the house, almost like an electrical current. By anchoring the drywall to resilient channel (instead of to studs and joists directly), you’ll greatly reduce sound transmission.

“This is especially important in basements,” says Maxwell. “I applied resilient channel to the bottom edge of the second-floor joists. It was quick to install and relatively inexpensive–less than a few hundred dollars for a 650-sq.-ft. ceiling.” Maxwell installed the channels every 16″, anchored by screws driven into the joists, beginning near the outside walls.

“With resilient channel, the sound vibration works its way into the drywall, but instead of continuing through to the opposite sheet of drywall, the sound sticks to the channel and doesn’t leave it until it hits the fastener, and by this point it’s been reduced by more than 50 per cent,” says Goyda. “The problem is resilient channel is easy to defeat. Let’s say you install the channels, thick drywall and acoustical batting–if you put even one drywall screw into a stud, you’ve defeated your entire noise-control system because now the sound has a direct path out of the workshop.” So keep in mind, if you’re going to put up a shelf or hook, attach it to a channel, not a stud.

Besides installing resilient channel, you can also build your non load-bearing workshop walls using 2×3 studs, offset from one side of the wall to the other, rather than using 2×4 studs that span the wall cavity.

“I tried this when I built my home office, which is opposite the family room,” says Rick Campbell of London, Ont. “Because the studs are offset, there’s no continuous connection between the two sides of the wall, so when the TV vibrates the walls beside the family room, I can’t hear it in the office, even though I’m right beside it.”