Reach Us
Cellulose Insulation Manufacturers Association

Assumption About Dense Packed Cellulose Settling

Cellulose Insulation Answer Man CIMA Graphic
Cellulose Answer Man: Your Source For Information

Michael D. asked:

I know even with dense packed cellulose in the walls, it will settle because of building movements. ?Will that cause any problems for even 1/2 inch of settlement in the walls? Like moisture issues?


Dense Pack Blown In Cellulose Insulation Wall Installation
Thanks for the comment and question. Your assumption is not correct however. When cellulose insulation is packed in a wall cavity at 3.0 to 3.5 pcf it is essentially spring loaded in the cavity. Assuming proper installation we would not expect the insulation to settle. Should settlement occur due to inadequate density (ie: improper installation) the problem would be loss of thermal performance due to greater air infiltration and an insulation void at the top of the cavity. CIMA recommends using an insulation contractor that specializes in cellulose insulation. Find CIMA Producers by states that can provide recommendations.


Have a question, add it to any post or the Contact Us page here on the Greenest Insulation Blog, or use the Contact Us form on the CIMA website.




2020-10-25 12:41:11
Margaret Alfieri says:

My attic space over an addition (with sloped or shed roof) was recently retrofitted with dense pack cellulose. The original plan was to have the installer crawl into the attic space and install the insulation that way and add roof vents but at the last minute, dense packing the insulation was decided. The contractor cut out holes in the soffits and blew in the insulation that way. My concern is that there is no ventilation and the little research that I've done (and been able to understand) is that dense packing can lead to moisture issues and actual damage to roof deck.

2020-10-29 14:06:06
CIMA Admin says:

Thanks for your comment. The recommended way to insulate roof assemblies of this type with cellulose insulation is the unvented dense-packed cavity design. It would be helpful to know the dimensions of the framing lumber in the insulated assembly.

2021-01-01 14:54:53
Tom Meyer says:

I'm looking into dense pack blown in insulation for my house built in 1972. My walls are cold in the winter and hot in the summer.

I'm thinking about doing this myself , I'm a retired carpenter and think I can handle the job , but I'm having a hard time finding the machine I'm looking for. Done some research and I'm looking for a Force 2 machine to rent.

Can you help me find this machine ?

2021-01-04 14:29:58
CIMA Admin says:

Suggest you use the Referral tool on our website to query CIMA Producers in your state who may be able to provide information. However, cellulose insulation blowers available for rental are typically the simple attic installation style.

2021-01-08 21:45:11
Tom Meyer says:

Hi , I'm looking into either having insulation professionally blown in my exterior walls , or trying to rent a machine and doing it myself.

I'm pretty confident that I can do the job myself , as I am a retired carpenter with 35 years experience in construction.

However I haven't found a company that is capable yet , or the machine that I need to rent in my area.

Any help you can provide would be greatly appreciated.