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Posted by: from Victoria
11/19/2012 at 5:05:06 PM

I want to soundproof between the lower suite and the upper suite. The lower suite is a normal 8ft height and the floor joists between the floors are a regular 10 inch joist.

What is the best method of sound proofing?

I have looked at both Roxul insultation and the suspended sonodboard system. I am looking to eliminate the normal daily noises that families make. Walking, TV, chairs dragged, etc.

Any ideas or suggestions?

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Date/Time11/19/2012 at 6:11:04 PM

We specialize in home theatre rooms our preferred method is 2 layers safe n sound followed by resilient channel and then sound board.

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Date/Time11/19/2012 at 6:22:39 PM

There are numerous ways to sound proof between floors.

Roxul insulation between the joists, as thick as possible is a start. Using a z bar / strapping between the joists and the ceiling drywall isolates the transfer of noise from walkling and vibration.

Also using sound proof drywall in the ceiling helps a lot, however it's expensive, about 10 times the price of regular drywall. But it is worth it, if you want a quiet room. Your heating ducts are the hard ones to sound proof, as they transfer voice and TV noise all over the house.

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Date/Time11/19/2012 at 6:29:47 PM

You can hang a T-bar ceiling below the existing ceiling using non sound transferring hangers, and you can lay fibreglass insulation batts above the sound restricting acoustic tiles.

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John from JALS Corporation in Welland
Date/Time11/19/2012 at 7:05:56 PM

The best way is spray foam. it will cost more but it does the job.

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Date/Time11/19/2012 at 7:39:08 PM

I would suggest talking to a local insulation contractor that handles 'cellulose fibre insulation' and they may be able to drill holes in an existing ceiling and blow in the insulation for sound proofing purposes.

Brent Murray

Reitzel Bros. Insulation


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Date/Time11/19/2012 at 10:35:59 PM


The magic way is drop the ceiling with resilien chanel and roxul safe&sound

Mario's Home Renovation


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Date/Time11/20/2012 at 5:37:04 AM

if you have no pot lights blown cellulose insolation that i think is the best if u have pot light u will have to install insolated boxes and then put the pot light in there

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Audio Authority in Vaughan
Date/Time11/20/2012 at 5:45:16 PM

Hi, this is Eli from Audio Authority.

Your correct in using Roxul Safe-N-Sound for between the floor joists, as this type of insulation fits snugly and won't sag. But I have a question for you. What type of flooring is above these joists? You may want to consider something under that flooring if you have access.

Also "hat channel" or "resilient" channel between the joists and new drywall downstairs will all help improve the sound loss through the floor. All readily available at Lowes or Home Depot.

You may also want to add caulking (adhesive) to the meeting point between floor joists and plywood to silence any squeeking of the two surfaces.

Hope this was of help.

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Richard in Nanaimo
Date/Time11/20/2012 at 9:21:05 PM

Hi Brenda,

I've just bought a house with the same problem you have and am currently doing the "fix". I'm in the relatively unique situation of having a son with a Masters Degree in Acoustical Engineering. He's been an invaluable source of knowledge, steering me in the right direction.

None of the previous answers provides a complete remedy for your situation, but they all lean the right way to one degree or another. "Curing" your problem depends on how much time, effort & money you want to spend on it, and where on the moving scale of "soundproofness" you want to stop while still meeting both your, and your tenants, expectations.

Realize you're actually dealing with 3 different aspects of sound transmission.

1 - Transmission of airborne sound ( talking, TV, fridge noise etc). This kind of sound through walls & ceilings is measured as Sound Transmission Class (STC).

2 - Transmission of impact generated sound (walk, drag, drop, hit etc). This is measured as Impact Insulation Class (IIC). Note STC & IIC are not related. Sometimes doing things to improve one will actually worsen the other.

3 - Flanking Sound is sound that seeps through your ceilings and walls at weak spots (electrical boxes, heating ducts, holes where plumbing pipes exit, wall/ceiling intersections where sound travels through subfloor materials & unblocked passages from one space to another). It's crucial to fix flanking sound since it's possible to build walls and ceilings to STC 70 but only have an "apparent" STC (ASTC) of 40 because of all the sound that leaked into the space, meaning you wasted a lot of money building the STC 70 walls/ceilings in the first place.

To learn more & design your own solution these links will be invaluable. You'll have to pick out the pertinent bits and do a lot of extrapolation between docs.

Beware sound proofing contractors. Very few "professionals" even know about, much less understand this information.

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Date/Time11/21/2012 at 5:28:10 PM

Hi Brenda

Your on the right track. Here are the things you can do or combine together in any order:

1) add insulation between joists, roxol or pink insulation. helps stop high pitch sounds

2) add "Z" bar between drywall and joists. These are metal strips that run perpendicular to joist and help stop transfer of bass sounds.

3) 5/8 drywall board


Alair Homes

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Date/Time11/21/2012 at 7:36:33 PM

Fire and sound insulation should be there by building code 4 inch minimum, easy equation more insulation less noise, cut small access hole to se what is there, blow in more insulation and another layer of dry wall.

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Chris in Victoria
Date/Time4/16/2013 at 1:03:19 AM


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