If you’ve got paper thin walls and are always being disturbed by noises coming from the next room, you’ve probably wondered what you can do about it. This method is the same that the professionals use, and also can drastically reduce your heating bill when used on exterior walls.
The first thing I like to do is find out where the studs are in the room I’m working on. If you have one side of the wall you’re less worried about, say, a spare bedroom rather than your living room, I would work on that side. Use a stud finder, or just knock on the wall and lightly mark where the studs are with a pencil. Usually studs in a house are 16″ apart.
Before you start the actual process, I’d highly recomend laying down a tarp so any spills don’t end up on your carpet. Also having a wet rag on hand to immidently wipe up and foam that spills is a lot easier than waiting until you’re finished to clean up.
Once your area is all set up, you’ll need to have a drill with a half inch bit in it and your sprayfoam. Use the drill to make three holes between a set of studs, one next to the ceiling, one about one thirds down, and one two thirds down. Once you get more practice at this you can do it with just one hole at the top and one in the middle.
Start and the lowest hole, put the nuzzle of the soundproofing spray foam in and squeeze the trigger for a few seconds. Read the packaging to see how long the brand you are using takes to fully expand, and wait that time period. If the foam hasn’t quite reached the first whole, put the nuzzle back in and sequeeze for a bit longer.
Continue to put foam unti it reaches that whole. Keep track of the combined time you held the trigger down, this will give you an approximate time to fill one third of your wall. For example, if the bottom third took two three second squirts and one two second squirt, you will try one long eight second squirt for the next one. Continue to adjust how much you squeeze the trigger accoudingly. It usually takes filling two or three cavities before you get it down.
Repeat the whole procedure between each set of studs for the room you want to soundproof.
Once the process is finished you’ll need to patch the small holes and repaint the wall if desired.