We have a newer home with high ceilings. The living room, dining room, and kitchen are like one big room. Next to the dining area is a convenient bathroom, however, it's not soundproof. Do you have any ideas as to how to make it so? We have thought about putting small holes in the drywall and blowing in some type of insulation. If we did that, what do we use and where can we get the equipment to do it. Do you have any other ideas?

A bathroom next to a dining room can be very convenient, but the sound of a flushing toilet on the other side of the wall can be very embarrassing. Here's a million dollar question for our readers who build homes: why aren't bathroom walls soundproofed for privacy? It's a valid question, but I'll bet the soundproofing isn't done because of material and labor costs or it's simply overlooked.

I can make a couple of recommendations that may be helpful but will probably not be 100 percent effective. Because your walls are already finished, you are limited on what can be done without turning it into a major (expensive!) project. Also, because I'm not able to see the project, I can only offer suggestions on how to approach it. Quite possibly if I saw the project I might suggest another route. It may be possible to do the work from the bathroom side if there are no fixtures on the wall—unless you want to work around or over them; otherwise, you may find it easier to work from the dining room side.

Your first thought of blown-in insulation is a good one. Go to any home center or insulation company that sells bags of cellulose insulation. They should have an insulation machine to rent or borrow, depending on the amount of insulation you purchase. Cellulose insulation is made of shredded newspapers treated with fire retardants. According to the industry and government bodies, the product is nontoxic. Cellulose should be somewhat effective because of its ability to fill and pack the stud cavities.

The biggest difficulty in this project is to locate the studs so you will know where to drill the access holes. You'll need a stud finder, and I recommend purchasing any model by Zircon. (My favorite is their Triscanner—it's a must-have tool for the toolbox.) Once you've located the studs, drill a hole slightly larger than the insulation machine's nozzle in the center of the cavity up close to the ceiling. Be sure to keep the top of each hole down from the ceiling about 4 to 6 inches. That way you won't disturb the ceiling when it's time to finish the holes with mud and tape. Repainting the entire ceiling is a can of worms you'd rather not open!

This is a semi-messy project so place the insulation machine outside and run the hose in through a window or an exterior door. It's also a two-person operation: one person to fill the hopper with insulation and operate the machine and the other to use the hose to fill the cavities. Both you and your helper should wear eye protection and a mask.

If this doesn't soundproof the walls enough, then consider this next product. Its installation is simple but involves more work and cost than blown-in insulation. The end results, however, are very effective when combined with the blown-in insulation.

This product requires removal of the door casings, if there's a door(s) in the wall, and base moldings so you can install Auralex SheetBlok Sound Barrier, a thin (1/8" thick)—but very dense—black vinyl material that is quite effective in stopping sound transmission. Each 4' x 30' roll costs $339 and covers 120 square feet. It is easily cut with a utility knife or scissors and can even be doubled up to increase its effectiveness.

Auralex SheetBlok is not considered a finish wall product so you'll want to sandwich it between two wall surface products. For example, you could glue it to the existing wall and place a layer of 1/2" drywall over it. Since the required adhesive only serves to hold SheetBlok in place long enough to put a second wall covering over it, I recommend that you purchase Auralex SheetBlok Plus which has a pressure-sensitive adhesive back—just peel and stick. This will eliminate the mess associated with applying the adhesive. You can learn more about these products and to purchase by clicking on the product name(s) within this paragraph.

The installation of SheetBlok will require decisions on what to do for a wall treatment (finished wall covering). If you choose drywall, then be prepared to mud and tape the seams, including where the drywall butts up against adjacent walls and ceilings. This method will require you to repaint the entire room, including the ceiling, and you will need to cut back the carpet (if any) by 1/2" to allow for the drywall's thickness.

Not knowing your wall layout, I would be inclined to install paneling that is finished in a decorative finish or in real wood. That way adjacent walls and ceiling will not be disturbed and you could use finish trim (if needed) to finish out the wall. No matter which wall covering you select, the doorjamb legs (if there's a door on this wall) will require extensions so the jambs match the thickness of the new finish wall. This will allow you to reinstall the casings.

You have some decisions to make. From a cost standpoint, I suggest that you try the blown-in insulation first. If that doesn't effectively prevent noise transmission, then install Auralex SheetBlok Plus Sound Barrier.

I want to hear back from you once you have soundproofed the wall. Let me know which soundproofing method you chose and how it worked for you. I know the readers would also like to hear from you as well.

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C.R.S., Inc. · Spokane, Washington · USA