If you are sound proofing walls, you can use fiberglass in rolls for the job or blow in foam. The blow in foam for soundproofing the walls works very well in any room. There are many ways to soundproof the room, but if you have an existing wall, you might want to use the blow in foam to save money. Adding rolled fiberglass soundproofing would involve removing the drywall that is standing and installing the fiberglass barrier and then redoing the drywall.
Loose insulation comes in several different forms. There is fiberglass, cellulose and spray-in polyurethane foam. Fiberglass can contain recycled glass and may leave particles floating in your home’s indoor air, so it is not a healthy option.
Cellulose is chopped old recycled newspaper or wood fiber, treated with flame retardants, insecticides and other chemicals. If you do not suffer from any sensitivity to chemicals, cellulose insulation provides a high level of sound proofing and is inexpensive and easy to install.
Because the blown-in polyurethane foams expand to fill cracks and gaps and forms a tight barrier, not only does it provide high R-value insulation, it makes a pretty good soundproofing for walls.
On the downside, blown in foam is fairly expensive to install, since it requires a skilled craftsman and costs more per foot that cellulose or fiberglass. Below we give an outline of how it is installed, but this is probably not a job for the average homeowner to take on; specialized equipment is required and due to the expansion properties of the foam (it expands up to 100 times in volume when applied) you can damage the structure of your home.
In between each stud, make a small hole for the nozzle of the hose. This is where the nozzle will fit into the wall and blow the foam between each stud. The holes should be up as close to the ceiling as you can get. You can also do this in the ceiling to completely soundproof the room.
After you have all the holes made, start blowing in the foam. For the first hole, you will have to experiment until you fill and the hole and see how long it takes. If for any reasons, you have used cross beams between the studs, you will have to drill more holes to reach the lower half of the wall. Some older homes may have this problem. The way to check is to look by the lower outlets to make the foam has made it to that area. If it has not, you might have cross beam blocking the flow of the foam.
Continue this process until every wall has been done. Then do the ceiling the same way that you did the walls. Experiment with the first hole to see how long this will take for every hole.
After all the foam has been blown in, you now have to seal the holes. This can be done by using some compound and drywall tape. Use a trowel to apply some compound in the holes. Allow to dry overnight.
The next day, apply a thing coat of compound and add the small piece of drywall tape. Allow to dry overnight. The next day, apply another layer of compound remembering to make it as smooth as possible. Repeat this step the next day and make sure that this coating is very smooth so you will not have to sand as much. Allow to dry overnight.
Lightly sand the spots with 100-grit sandpaper and then texture and paint.
The Fiberglass Sound Proofing Walls
If you want to use the fiberglass for soundproofing, you will have to remove all the drywall in the room. This includes the walls and the ceiling. After you have this done, you can add the fiberglass to the walls between the studs. The fiberglass material comes in rolls.
This way will mean that you have to buy new drywall and the materials to tape the joints and the nail holes. It is a better way of soundproofing, but the time and work will require more money. This process is better for remodeling jobs or new home buildings.