# Blown Insulation vs. Rolled Insulation



## wombosi (Apr 22, 2008)

I recently had my entire house insulated with icynene (expanding foam) from the outside.

Depending on your siding, this is pretty easy to do. If clapboards, remove a board or two every 2-3' vertical feet. Then drill some holes and presto.

The foam will also act as a vapor barrier for your shower. 

Alternatively you could do blown cellulose or fiberglass, but they're both junk compared to foam, and the price and installation method will probably be the same. Either of these will get wet and moldy almost guaranteed in your shower.


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## Windows on Wash (Aug 30, 2011)

wombosi said:


> I recently had my entire house insulated with icynene (expanding foam) from the outside.
> 
> Depending on your siding, this is pretty easy to do. If clapboards, remove a board or two every 2-3' vertical feet. Then drill some holes and presto.
> 
> ...


Icynene is not vapor barrier.

It is a class III vapor retarder at best with typical permeability ratings of about 5 or above and is certainly considered vapor permeable.

How is cellulose "junk" compared to foam? 

Open cell foam moves moisture just as readily as does dense packed foam and is not more of an air barrier as well.


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## Windows on Wash (Aug 30, 2011)

L.Stein said:


> So the contractor I hired to redo my shower floated the wall, when I suddenly realized he never replaced the insulation that was removed (I had asked him to do it and he forgot). He's recommending blowing the insulation in from the outside. I'm not excited about the thought of punching holes in my exterior wall, so I wanted to know if anyone had experience with this and the upside and downsides of this method versus typical rolled insulation.
> 
> Thanks,
> 
> Lloyd


What is the construction of the shower? Did he use Kerdi, Duroc, Hardie board, etc?

Where is the home located?


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## wombosi (Apr 22, 2008)

Windows on Wash said:


> Icynene is not vapor barrier.
> 
> It is a class III vapor retarder at best with typical permeability ratings of about 5 or above and is certainly considered vapor permeable.
> 
> ...


well, pardon me, sir. maybe i'm wrong about the vapor barrier, but no one will ever convince me that fiberglass or cellulose is as good as foam. the proof is in the pudding. 
i have icynene in my whole house and attic roof. no ice dams and no icycles, while my neighbors do have those.
not wishing to start an argument here, and i am definitely not an insulation pro. i just happen to think foam is vastly superior to anything else on the market right now.


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## Windows on Wash (Aug 30, 2011)

wombosi said:


> well, pardon me, sir. maybe i'm wrong about the vapor barrier, but no one will ever convince me that fiberglass or cellulose is as good as foam. the proof is in the pudding.
> i have icynene in my whole house and attic roof. no ice dams and no icycles, while my neighbors do have those.
> not wishing to start an argument here, and i am definitely not an insulation pro. i just happen to think foam is vastly superior to anything else on the market right now.


No need to pardon you and it was not personal. I just want the original poster to have the correct information in front of him.

Foam is great and certainly better than blown in fiberglass. The primary benefit of foam that you are experiencing is the fact that it is an air barrier. Air loss is the biggest issue that plagues most home and when you spray foam, you, in large part, eliminate that part of the equation.

If this customer is concerned about the walls behind his shower, he should look into a drip foam (closed cell) that would provide a less permeable (class II) vapor retarder at that point.

Foam has its place but you can build more traditionally with foam to the exterior of the wall assembly and actually out perform an Icynene stud cavity home.


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## L.Stein (Jan 27, 2012)

I'm not a handy person, so I'm going to try and answer the questions you asked as best I can, please humor me.

The shower wall was floated with cement and waterproof paper (not sure what the technical name for that is), on top of that is tile. The house is located in Southern California, we don't see snow, or even temps in the 30's, having said that, I want to blow the best insulation I can while I'm paying for it.

Thanks to everyone for the help with this. I truly appreciate it.

Lloyd


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