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Serious Soundproofing: “I Can Hear Your…”

By May 18, 2011

You bought the condo of your dreams. You moved in all your favorite furniture. It’s your first night in your new bedroom and you think you must be too excited to sleep. But what really woke you up was the “clip, clop, clack” as your upstairs neighbor arrived home and navigated across the wood floors above you, and then you hear…

…the distinct tinkling of their toilet.

That’s the point when you realize you might need to start looking into earplugs and sound machines. Or, it may warrant a more serious soundproofing approach because sometimes you don’t have an obnoxiously noisy neighbor but your building does transmit noise between floors (even *gasp* in a new construction, concrete building).

One Urbnlivn reader took the time to explain a few noise culprits:

As you can see in this demolition photo of the McGuire, new concrete buildings generally have only 5″ thick concrete slabs – which you think would result in a quiet building because it is concrete.

However, drainage for toilets and bathtubs extends through the concrete and into the lower height ceiling of the bathroom below. The developer might put in 4″ of insulation above that lower ceiling, but that’s not enough if nothing is done to dampen noise at the source — on the pipe.

In addition, it’s far too common that a contractor short-circuits a sound isolation technique like a double stud wall by attaching a pipe to both sets of studs.

In other rooms of the condo, the problem between units is often a lack of acoustical sealant around the perimeter of a wood floor and around electrical boxes. A friend recently told me that the floor above her doesn’t have any caulking around the electrical boxes so she can see light from the above unit at night. In this case, the least invasive approach would be to take off the electrical plates and apply a seal between the drywall and the electrical box.

Unfortunately, our reader’s current situation is the unenviable one:

At the new downtown condo (where thankfully I’m just renting), I can hear my neighbor use the toilet and empty the bath because the dropped ceiling above my bathroom adjoins the bedroom.

However, he’s solved the upstairs noise issue before:

The soundproofing I’ve done in the past has been pretty basic (just offset ceiling joists with an IsoMax ceiling clip). The image below shows a metal ceiling joist added parallel to the existing wood frame ceiling joists. It supports an IsoMax clip that holds 25 gauge hat channel. The drywall gets screwed into the hat channel and the 1″ separation between the hat channel and the original ceiling joists ensures that a screw doesn’t accidentally screw into the original ceiling joists (ensuring noise can’t be transmitted directly).

My original inspiration was Frederick Anhalt who wrote about using independent ceiling joists (offset from the floor joists of the unit above) in 1005 East Roy.

And he would again if he could:

If I owned the unit, I would cut a 15″x24″ hole in the drywall along the lower ceiling joists in the bathroom above my toilet.  That would provide the best access to the drainpipe above, where I could reduce the noise at the source by painting QuietCoat on the toilet drainpipe, surrounding it with molded fiberglass insulation, and then wrapping that with mass-loaded-vinyl. Then I would stuff as much Thermafiber mineral wool into the dropped ceiling as possible.

How does this guy know so much? Well, he once went to great lengths to build a veritable panic room by installing a secondary ceiling and two sidewalls inside an existing bedroom. To that, we said “Wow” but he quickly pointed out that building a room within a room should not be anyone’s first choice (or their second or third…).

Even though it was quiet when I finished, it took all my vacation for the year and most nights and weekends for 6 months. If I hired out the work, it would have easily cost $20k just for a 15×10 room. Sometimes it is better to just sell, then go buy a condo with no upstairs neighbors — which is what I would have done if I didn’t have such a killer view.

So if you are looking for simple: earplugs and sound machines. And if you need more: ceiling clips, mass-loaded vinyl, and mineral wool (but not before checking in with your HOA, of course – some projects can require HOA approval).