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Dense Pack Or Wet Spray Cellulose vs. Flash-Fill Insulated Walls

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Cheryl asks:

Hello, I’m building a new house and I’m trying to decide between dense pack and wet spray cellulose in my 2×6 walls. I’m also trying to decide weather to use closed cell spray foam in conjunction with the cellulose in the wall cavity. I would love to talk to someone about this.


wall cavity filled with spray applied cellulose insulation
This is actually a two-part question and we are glad you pose it. First, the question of whether to use dense pack or wet spray applied cellulose insulation in 2×6 walls is a bit like choosing between a Lincoln or a Cadillac. Both will do the job and provide all the benefits inherent with using cellulose insulation. It really comes down to the contractor involved and what they are most experienced with and prefer.

The second part is whether to do a “flash and fill” job…that is spray a thin layer of foam in each cavity and then fill the cavity with cellulose insulation. While this is not needed in most climates when using dense packed or sprayed cellulose in a wall, of the two sprayed would be the better option although ether can be used. If you are in an extreme close area with Heating Degree Days in the 9000+ range it may be advisable to consider “flash and fill.” Again, check with your contractor.

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2022-01-10 14:00:27
Artur says:

Use closed cell and than fill with open cell sprY foam.