# How to properly install Roxul soundproofing wool?



## AtlanticWBConst. (May 12, 2006)

Installation of any sound-proofing or sound-attenuation material requires a tight and complete insertion of the product. (Example: When installing acoustic-rated sheetrock, acoustic sealant is to be used at all floor and ceiling connections, as well as around all electrical and lighting boxes. This creates a complete seal of all possible gaps in the wall's surface materials).

The same is true when installing thermal-rated insulation.

Now, regarding the gaps in the wall's thickness: The Roxul may not have the same thickness as the wall cavities. So a space may exist between the floor sheathing and the insulation, creating an "air chamber". Leaving an air chamber can actually aid in sound reduction. Sound reduction is about "changing sound waves". Air chambers help to accomplish that.

_As far as leaving gaps "around" or "between"_ the acoustic insulation - that pretty much defeats the purpose of it's application. It should be snug to creat a complete "barrier" within the wall of the two room/floor level - spaces you are trying to isolate.


You can review the illustration at the end of this link: 
http://www.a-ztech.on.ca/insulation3.htm


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## renogirl (Apr 23, 2008)

*Filling in gaps with Roxul?*

Thanks for your response. At this point they have already cut and placed the pieces of wood between the ceiling joists, but it doesn't look "tight", do you think we can cut thin slices of wool to fill in the gaps, or would they have to start again?....
Thanks


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## AtlanticWBConst. (May 12, 2006)

They can cut smaller peices to fill in the gaps. As long as it is "snug", you are accomplishing the creation of a "solid" barrier and separation of the areas.


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## renogirl (Apr 23, 2008)

thank you! much appreciated!


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## renogirl (Apr 23, 2008)

*Roxul soundproofing not working.. any ideas?*

We have just installed Roxul soundproofing between ceiling joists, (as snugly as we could), but we can still hear everything (!) upstairs.... any ideas on what to do before we put the drywall up?

Thanks!


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## AtlanticWBConst. (May 12, 2006)

renogirl said:


> We have just installed Roxul soundproofing between ceiling joists, (as snugly as we could), but we can still hear everything (!) upstairs.... any ideas on what to do before we put the drywall up?
> 
> Thanks!


There are other ways that sound can be transmitted in a home.

Recent Discussion. I posted links on this thread that explains sound transmission and other ways to reduce sound: 

http://www.diychatroom.com/showthread.php?p=118012#post118012


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