Need ballpark costs of soundproofing a small condo

jaxoSeptember 16, 2010

I'm considering buying a small ground floor apartment-style single level condo of about 700-900 square feet and likely to be between 5 and 10 years old. I have not picked out anything yet, but they are all at least vaguely similar in size and layout.

If I buy, before I move in, I want to get it soundproofed as well as is practical, by replacing interior dry wall with QuietRock on all the walls that are either shared with neighbor or that have exterior (street or parking lot etc.) on the other side. I also want to add additional soundproof glass over the sliding glass patio door and medium sized (3x3?) window that would be in the bedroom or living room.

I would also like to remove the ceiling over the approx 12X12 master bedroom, treat the underside of the floor above with soundproofing and then replace the bedroom ceiling with a more soundproof version.

These are the things I'm looking at.

Quietrock walls facing outside and shared wall:

I would use "Solution 3" over the bedroom ceiling: SOUNDPROOFING CEILING

I would add soundproof windows over the existing windos and sliding glass door to the patio:


This is just an example of a floorplan I might choose"

If I chose the floor plan pictured above, I would want QuietRock along the master bedroom wall all the way to the walk in closet, soundproof the master bedroom ceiling, add soundproof glass over the slider to the patio and the window behind where the sofa is shown.

Other condos I would consider buying would be somewhat similar to this. What price range should I expect the cost of having a contractor or handyman do this work?

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None of the materials you suggest will "soundproof" the unit. All you can hope to do is reduce the sound transmission to a more tolerable level.

The advantage of QuietRock and Green Glue is that they provide a modest amount of sound transmission reduction in the smallest possible space. There are other cheaper and often better solutions that add thickness to the walls and ceilings. Adding to the thickness of these elements also avoids the necessity of getting approval from the condominium association for modifying common walls and floor/ceilings especially if the modifications result in an increase in sound transmission (due to poor installation of a single layer sound barrier - cracks can defeat the benefit of any system).

If losing an inch or two of space is acceptable, I would seal what is there and add a layer of 5/8" GWB at the shared walls and the ceilings supported by a resilient system like plain resilient channels or the ISO-MAX system, etc.

If you feel insulation is necessary (less than 8" only helps to reduce sound that gets through cracks and bounces around in the cavity) you could blow cellulose thermal insulation into the wall and ceiling cavities, then patch the holes well. Of course, any recessed ceiling light fixtures would have to be removed or replaced with ones rated for contact with insulation unless there is a unit above in which case the fixtures would probably be in fire rated boxes. You need to look at the drawings of the building. In any case, recessed light fixtures are not a good idea for sound control.

The next level of protection would be a second layer of 5/8" GWB with or without another resilient support system.

As for the windows you might investigate exterior or interior storm windows first. The most sound resistant system would be interior solid shutters with cam latches and perimeter acoustic seals.

Here is a link that might be useful: ISO MAX system

    Bookmark   September 16, 2010 at 8:41AM
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I don't know the answer but don't forget the add-on projects like re-texturing the walls and ceiling, repainting, replacing all the moldings (door molding, crown, baseboards), etc.

    Bookmark   September 16, 2010 at 1:11PM
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If you are sensitive to noise -- like I am -- you may find it is better to spend a little more money on a unit that is already fairly soundproofed: for instance, with poured concrete floors and isolated double-wall construction between apartments, or cinderblock separation. My own experience is that you can spend a lot of money on retrofit soundproofing and still only reduce the annoyance somewhat. Good luck, whatever you do.

    Bookmark   September 17, 2010 at 3:48PM
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Concrete slab floors transmit impact noise better than any other structure type so they are not necessarily better than wood framing. Double studded walls are not necessarily better than well constructed resilient membrane walls. All of these details and systems are easily defeated by poorly sealed perimeter cracks.

I have worked with several very good acoustic engineers on some very difficult projects from high-end high-rise condominium units to recording studios and learned that the logic is not obvious or easily understood and how easy it is to defeat the benefit of good details with seemingly beneficial modifications or additions.

In general, most acoustic information on the internet deals with sound control for audio systems rather than sound separation in dwelling units and even then it often concentrates on marketable materials and systems with company conducted test results that are often misleading.

In conclusion IMHO design for sound abatement in an existing dwelling unit is not a DIY project.

    Bookmark   September 17, 2010 at 5:31PM
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The problem with the idea is that any floors or walls you address between units must be fire rated assemblies with typical 2 hour minimum ratings.

Unless the materials you plan to install to abate noise also maintain that 2 hour fire separation rating, you will not be permitted to install them.

Because this is a commercial residential building, you will also normally need an architect or engineer to design and stamp these alterations in order to get building permits.

It is doubtful you can achieve the fire separation rating without the use of TYPE X drywall and you therefore may not be permitted to use the system you have been considering.

Because of this, as macv said, there is little about this project that is DIY.

Start by consulting with an architect or engineer to get a good understanding of the costs associated with such a project....including the potential rewiring of the unit to accomodate thicker walls and ceilings.

Otherwise you may want to consider something other than condo living if noise and cost is a problem for you.

    Bookmark   September 18, 2010 at 7:00AM
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I do not want to do this as a DYI project. I just wanted a ballpark price range of what to expect contractors or a handyman to quote to do something like this so I can recognize a too high or unrealistically low price.
It will be a small 1 bedroom ground floor condo that will likely be under 800sq ft total and only some of the walls and only the bedroom ceiling would be soundproofed along with 1 slider and maybe 2-3 medium sized windows.

I would hope that since the materials such as QuietRock are deigned for this purpose, they would be made out of materials that do not violate fire ratings or any other building codes.
Needing an architect consultation to replace interior drywall sounds overs the top. However, even if a quick architect consultation plus building permite were needed, the cost of this plus cost and materials and labor added to the cost of the condo should still be a fraction of the cost of a single family home in the same area. The cost should be worth it since I plan to live in the condo for decades and even if I don't, it will probably be either one of very few, or even the only condo in the complex that was soundproofed beyond minimum code requirments and that should be a selling point at resale.

There is not really a "common" wall between units. There should be a space between each unit with each condo having their own separate interior drywall, so replacing my drywall will not touch theirs. If necessary, the ceiling can be done without attaching anything to the upstairs neighbors subfloor, but it will not be as effective if that step is skipped.

This will not be a high rise building. It will be 3 stories max and likely only 2 stories.

A single family home will cost much more than the cost of a 1 bedroom condo plus adding soundproofing and does not guarantee silence unless you have acreage. I live in a single family home know and my neighbors still cannot play loud music or people 2 or three houses away will hear and feel the bass. I could hear a neighbor's teenage child playing bass guitar despite being across the street 2 houses away and having all the windows and doors shut at my house.

    Bookmark   September 18, 2010 at 8:14PM
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As I said: look for a place that is already built with sound-proofing features. They're out there...I've lived in them.

    Bookmark   September 18, 2010 at 9:07PM
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There is nothing like that were I'm looking. It is in California and we cannot have solid concrete walls due to construction techniques required for earthquake resistance.
I don't have that many condo complexes to choose from. There are really only two or three complexes in the area I'm seriously considering. So, I will need add additional soundproofing if I want more than minimum code requirements for condos.
There is no getting around it and I should not be the first person to ever have this done.

One of the much more expensive complexes has strict CC&Rs that should prevent high levels of noise regardless of soundproofing or lack of it. So, that is one option, but I would prefer the more moderately priced complex and just make a cocoon out of it and pocket the savings. Even if I spent $10K on labor and material soundproofing, retexturing and repainting, I would would still be well ahead of buying in the more expensive complex and I hope to spend a whole lot less than that for such a small place.

    Bookmark   September 18, 2010 at 9:27PM
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You'll spend a lot more than 10K. And "soundproofing" is a misnomer. You can modify the sound that reaches you by spending a lot of bucks, but you're not taking a place that you can hear your neighbor playing music at 80 dB and reducing that sound transmission to 40 dB without completely rebuilding both units. What you are proposing doing here is darn expensive for very little actual gain, even in a single family home. A better built unit with white noise machine would provide more sound masking capability as the 50K you propose to spend and only cost you $100.

    Bookmark   September 22, 2010 at 10:55PM
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Rather that "rebuilding" an entire condo, how about just soundproofing one single room (the master bedroom of approx 12X14ft)?
Add a soundproof window on the inside over the existing window, QuietRock a 12X9 wall that faces the exterior and add sound abatement to the ceiling in that room.
When I want quiet, then I just go in the bedroom and shut the door instead of trying to soundproof the entire condo.
It just needs to keep out normal noises such as creaking of upstairs neighbor walking around and noises of people talking loudly directly outside the condo.
If people are doing obnoxious things like blasting music, screaming, running on a treadmill or jumping on a trampoline, then the HOA will need to handle that.

    Bookmark   September 22, 2010 at 11:25PM
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All gypsum drywall is fire resistive but type Type X and Type C are designed to stay intact for a certain length of time and then pass the fire hose test so covering a fire rated wall with any kind of drywall increases the protection.

If you disturb a fire rated assembly in any other way you will need a stamp from a design professional.

    Bookmark   September 23, 2010 at 11:05AM
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