Blown Cellulose vs. Spray Foam

[haugy]

Blown Cellulose vs. Spray Foam, with a Quote review as well

I'm at the insulation stage for my shop. There's so much gibberish of information out there my head started to spin.

I'm just trying to get a simple Pro/Con rundown between these two. I've got a pole barn, 30x40x14', that I will be drywalling in. So I've got air coming through everywhere. This is in humid as hell TN. Which also can get very cold in the winter.

Some of the things I'm curious about:

-Which is better for airflow control?
-Which ones require a vapor barrier, if any?
-Insulation value, which one is better?
-Price?

Those who are experienced, please assist if you can. If you went with one of these two choices, why? I'm looking at these two for the walls of my shop, and simple blown in insulation for the attic area.

Please chime in.

 

[hunt]

i have experienced this first hand, long run, spray foam insulates better.

 

[walrus]

Closed cell spray foam stops water and air. If money is no object foam is where its at. Cellulose is good stuff also. Might want to consider it in your attic space if you have that and then foam the walls.

 

[jklingel]

Agreed on the above. If you are "green" oriented, then use cellulose. FOR SURE use the Airtight Drywall Approach to stop air. You very likely do NOT need a vapor barrier in TN, but you DO need to stop air flow into the insulation if you use cellulose.

 

[NUTTSGT]

I hate blown cellulose insulation.

 

[haugy]

Well I just got a quote for closed cell foam 1-inch thick around the walls of the shop. I think I'm going to go that route. They included an optional fiberglas batts if I really wanted to seal up the shop, and the roof which I know I'll be doing with sprayed in foam.

Take a look at the quote, and let me know what you think. This is a 30x40x14' pole barn that I will be drywalling.


1. Exterior Walls of Metal Building: Spray 1" of Closed Cell Foam - 14' Ceiling Height
TOTAL: $ 1,650.00

2. Exterior Walls of Metal Building: Install R19 Fiberglass Insulation
TOTAL: $ 660.00

3. Attic of Metal Building: Install R30 of Blown Fiberglass Insulation
TOTAL: $ 480.00

 

[trythis]

How about both!
1" of foam against building for air block, then fill space between drywall and foam with cellulose. The foam is expensive and even more so if you use closed cell foam, so using a very thin layer is going to be cheaper. The thin layer lacks some of the R value.
You're in TN, its humid and it rains a lot. You building is leaky, or will be. If you use open cell, the water will get in the foam and stay there and start to rot and mold.

Using the cellulose will prevent the bugs from nesting and it wont mold.

 

[Busted_Knuckles]

I think the way you are going is best, with the foam to stop the air, because nothing else will even come close, but as I posted in another thread, I think you where asking, I stated that Ive been told time again by each sub I talked to, the closed cell with break free when the wall moves, and you will have cracks where it meets each post. The stuff is so rigid, it does not flex. Go push on your walls if you dont think they move. I was givien samples to play with, I understood it when I was handed a sample. The open cell you can bend and pull on, the closed cell is super rigid.

Yes, you give up R-value going to the open, but once you have air infiltraion, the whole R-value dont mean much of anything. The open also acts a vapor retarder, and will allow moisture to leave if it builds up behind it.

Food for thought, and more research.

 

[haugy]

I think the way you are going is best, with the foam to stop the air, because nothing else will even come close, but as I posted in another thread, I think you where asking, I stated that Ive been told time again by each sub I talked to, the closed cell with break free when the wall moves, and you will have cracks where it meets each post. The stuff is so rigid, it does not flex. Go push on your walls if you dont think they move. I was givien samples to play with, I understood it when I was handed a sample. The open cell you can bend and pull on, the closed cell is super rigid.

Yes, you give up R-value going to the open, but once you have air infiltraion, the whole R-value dont mean much of anything. The open also acts a vapor retarder, and will allow moisture to leave if it builds up behind it.

Food for thought, and more research.

That's a good thought. Would it be counter productive or useless to put up a vapor barrier between the foam and batts? It sounds like no matter which one I use, closed or open cell I have to worry about moisture at some point. Vapor barrier is cheap and worth it if it does the job.

 

[Rosco]

That's a good thought. Would it be counter productive or useless to put up a vapor barrier between the foam and batts? It sounds like no matter which one I use, closed or open cell I have to worry about moisture at some point. Vapor barrier is cheap and worth it if it does the job.

I would not add a vapor barrier if you use foam, either open or closed. Just add unfaced batts or blown cellulose for R-value. If you add a vapor barrier the chances of moisture getting trapped increases. If moisture gets through the foam you want it to be able to breath.

Rule of thumb I have found after several hours/days/weeks of research is vapor barrier on one side only. Of course there are differing opinions, but I do not think that anyone will tell you that leaving the vapor barrier out is a bad idea.........several will tell you that installing it is a bad idea. The odds are in leaving it out. Spray foam will eliminate air/moisture infiltration to the best degree possible.

Good points on the closed cell foam above. There are several reasons I did not use it. For the cost, I would like to see a wall/roof that has had closed cell foam taken apart after 20 years..........wonder what we will learn then??

 

[haugy]

Good points on the closed cell foam above. There are several reasons I did not use it. For the cost, I would like to see a wall/roof that has had closed cell foam taken apart after 20 years..........wonder what we will learn then??

What are some of the reasons you wouldn't use closed cell? The points he made above definitely have my attention, and they seem very plausible and something to consider.

 

[HomeBrewA4]

Open cell has a 3.5R value per inch where as the closed cell is 6.0R per inch. We have probably used just about every maker of spray foam in our machine at work. We use open cell for mainly sound and closed cell for the fact that is fully seals the bay air tight and keeps all moisture and air from entering, whereas open cell can "leak" air or water vapor.

We do not do cellulose wall spray, which is water and cellulose to bond it long enough to get a barrier up to hold it in, but once it drys and over the years, it falls, the air pushes out and it drops height in your bay.

But I see you are mainly asking about blown cellulose.

Blown cellulose uses air to "fluffin" it up once its blown out. To go in your wall they would have to drill a hole at the top and feed it with the hose, like we do on "drill and fills". Problem with blown cellulose is, in the matter of 3-4 months, you have already dropped an inch or so. See, the air continuously pulls itself out of the insulation and it drops down in height, which lowers your R value. We have blown houses at 12" which is r38 and if they dont goto final for 2-3 months, we have to go back and blow on top of it, because it had settled below code. (We usually blow at 14-15" to combat this, but it depends whos doing the blow in... hell, we have seen houses get to the point of being blown, blow it, financing falls through, they sit for a yr or so and still need reblown due to falling below code).

I would personally do closed cell in your walls, i'd go 3-3.5" for a R19 which is code here, r13 might be code for you guys, if so, do 2.5". Then I would blow the rafter/attic area with blown fiberglass instead of cellulose. you are going to spend more this route today, but you wont ever have to add to it later. Blown fiberglass does not lose its R value over time, it also covers twice as much sq footage per bag, then cellulose. (We use Knauf JetStream blown fiberglass)

Our prices at the shop would be .85 per sq ft at 1" of closed cell and I think (I cant find my new price sheet, dangit) blown fiberglass is 1.25 per sq ft at a R38.

Sorry I didn't do too many pro's/con's for you, but I absolutely would not use blown cellulose in your walls. If you did, in 1 years time, you could be able to cut 6" or so of drywall from the top of your bays and it would be empty where the air is coming out and the cellulose is settling in the cavity.

Enjoy your garage whichever route you take.

Another option might be to use fiberglass bats. We batted a 40x60 pole barn that the guy had studs between his posts and it came out to 24" on center.

EDIt- You can also do a "flash and batt", which you would get a .250-.500 flash of urethane and then a r13 batt over that, depending how thick your studs are. If they are 2x6 or 6x6 posts, you can do 1" of foam and r13 and have the same R value as code for a heated living space. Honestly, the options are endless. You can have a flash and then an 11 if you want. But getting to r19 (or r13, whatever code is there) is going to leave it like your house, if you are heating it.

Reference - 2009 code changes here puts us at using 2x6 studs and r21 insulation. But we do a lot of flash and batts for the more luxury home builders due to the full sealing of the foam. Its truly energy efficient.

 

[haugy]

Thanks for all the information HomeBrew. I appreciate it.

Yeah, I'm looking at 1" of closed cell on the walls, with R19 batts in between all the studs. Since I'm 6x6" posts I'll be using 2x6's so I should have plenty of room for that. And then I'll be doing blown fiberglass in the roof.

HomeBrew, what are your thoughts on what Busted Knuckles mentioned about problems with Closed cell cracking and creating air gaps?

 

[HomeBrewA4]

you cant do 1" foam and r19 on a 2x6. A 2x6 is roughly 5.750 and R19 is 6.250 add an inch to that and you will never get it stapled or drywall hung without popping it.

You are better off going 1" with closed cell (6.0r value) and a r13 batt (giving you a total of r19). The little bit of air space left, will act as a sound deadener.

The only way I ever see closed cell cracking or falling apart, is if the surface is contaminated, but the stuff we use, I have NEVER seen it crack. I have seen it not stick due to an agent used on the block wall, and it came off in a solid sheet that we had to break up ourselves to remove it.

I have infact, seen open cell crack and not only that, but when shaving it down (if you fill the bay, as that is really its only way of being effective) it doesnt shave clean like closed cell, it cracked it/leaves craters where more comes off then it should.

Energy Star code up here is pretty tough, especially in my township. We have been using urethane for 8 years without any call backs or any type of problems in any job, residential or commercial.

EDIT- our foam jobs are even inspected by the township and like I said, our inspectors are tough and by the book. we have never failed a foam job. batt jobs occasionally for little stuff, but never a foam job.

 

[haugy]

you cant do 1" foam and r19 on a 2x6. A 2x6 is roughly 5.750 and R19 is 6.250 add an inch to that and you will never get it stapled or drywall hung without popping it.

You are better off going 1" with closed cell (6.0r value) and a r13 batt (giving you a total of r19). The little bit of air space left, will act as a sound deadener.

I bet he went that way since I have 2x4 girts on the outside of the 6x6 posts. Creating a gap between post and wall. Foam coats the whole wall 1" thick, and then with 2x6's that would leave enough room for the R19. I may have him price the R13 to see the difference.

 

[whitejeeptj]

Been reading here for a while now, this is my first post...I realize this thread is a few months old................

I am builidng a pole barn for use as a second home, this will be in Louisiana so it is hot and humid with temps in the winter months sometimes getting into the teens (for a fews days).

It will be a 30x40x12 living space with 6/12 scissor trusses. I will be putting knotty pine tongue and groove on the ceiling. I do not plan on any ridge vents, gable vents or soffit vents. One builder I spoke too recommended using bubble wrap under the metal and then spraying open cell foam in the attic and the walls directly on top of the bubble wrap. I may or may not blow in fiberglass over the tongue and groove ceiling to add R value.

What do you think of this idea?

 

[jklingel]

Bubble wrap under spray foam? What is the reasoning on this vs plain spray foam?

 

[whitejeeptj]

The reasoning (from what I gather) was to be able to use open cell foam vs. closed cell foam. For the open cell foam the bubble wrap would serve as the vapor barrier keeping condensing water from infiltrating the open cell foam.

I guess it would serve other purposes as well, like open cell being cheaper, more flexible, and the bubble wrap would prevent the treated wood the barn will be constructed with from possible reaction with the metal siding/roof.

Does this sound like a good,bad, or confused idea?

Oh yeah, another reason......incase a metal panel needed changing it would not be "glued" in place.

 

[jklingel]

The wrap/foam may work, I've just never heard of that method. If you are talking about spray foaming against the metal roofing, then maybe insulating over the tongue and groove, then you have unvented insulation; that does not sound good. Normally, ceiling insulation has venting over it, to let out any moisture from the conditioned space. I've never foamed a roof, but what seems typical is to sheath the roof w/ plywood (not OSB), then spray w/ closed cell foam. Buildingscience.com has many articles on this; check there. Hot, humid areas have special needs (perhaps exterior vapor barrier/retarder in the walls, etc).

 

[green.bubbly]

What part of Louisiana are you in? I am in Lafayette and I am about to start on a 40x48ish metal building as a home as well.

I have spoken to a couple of insulators that suggest a bubble type foil or similar thermal break material between the metal skin and the beams. The reasoning is to stop any thermal conducting through the metal. Then use the foam over that.

 

[jklingel]

thermal conducting? that is what the insulation is for in the first place. (breaking therm cond is why people put xps between their slab and foundation wall, or use a double stud wall.) i have never heard anyone say anything good about the insulation qualities of bubble wrap, but maybe not having the foam stick is for a good cause. my gut does not see why the foam should be "loose", but that is just a gut speaking. j

 

[whitejeeptj]

What part of Louisiana are you in? I am in Lafayette and I am about to start on a 40x48ish metal building as a home as well.


I have spoken to a couple of insulators that suggest a bubble type foil or similar thermal break material between the metal skin and the beams. The reasoning is to stop any thermal conducting through the metal. Then use the foam over that.

I am in Lafayette as well and will be building a pole barn for use as a camp on Toledo Bend. If it goes well I may build my next house this way too. I know of a planned pole barn house that will be built in Eagan.

This is exactly what I am thinking of. Will the bubble wrap (being snug up against the metal beacuse of the foam) inhibit its ability to stop condensation? Will the foam up against the bubble wrap cause the foam to loose its "making the building more rigid" qualities as well as be less effective against air leaks? Should I just forget about this method and pay for the CC foam?

 

[whitejeeptj]

thermal conducting? that is what the insulation is for in the first place. (breaking therm cond is why people put xps between their slab and foundation wall, or use a double stud wall.) i have never heard anyone say anything good about the insulation qualities of bubble wrap, but maybe not having the foam stick is for a good cause. my gut does not see why the foam should be "loose", but that is just a gut speaking. j

j, Here in Louisiana we are most concerned with keeping cold air in and moisture out, not loosing heat to the outside......it is *&^*^ hot most of the year here. The bubble wrap is only a vapor barrier/condensation dripping on the ceiling preventer.
I agree with your gut on the loose foam thing....that is my main concern holding me up on the idea of spraying OC foam on bubble wrap.

 

[swvega]

I've got a 30x60 morton pole building. I used fiberglass batts in the wall with vapor barrier and blow in fiberglass in the ceiling. Morton said if I used cellulose in walls or ceiling there would be no warrantee on the trusses or tin on building. They've had the chemical in cellulose eat up the tin on trusses and side walls when it gets any moisture on it.

 

[PaulR]

Anyone ever use the DIY kits? I didn't even know you could DIY until I looked. Seems it would be good for fix-ups, basement rim joists....

http://www.fomo.com/handi-foam-two-component.aspx

There's also one called Tiger Foam.

 

[haugy]

Just to chime back in here on my thread.

I went with the spray foam. I went with 1" thick spray foam to really seal up the shop. With the girts, and the 6x6" posts I had more than enough room for the spray foam, and then batts. I wanted batts so I could easily run wires in the future if I ever needed to. Plus for ease of installation.

The spray foam really tightened up the shop, and made it quieter inside. I've got the foam, then R-19 batts, and now drywall. With a torpedo heater I can keep it at 70 degrees really easily. I know as we had to do that for the mud on the drywall to dry.

Once I put in the ceiling with R-30 sprayed in, I know this shop will really hold temperature well. I'm excited.

 

[PaulR]

Just to chime back in here on my thread.

I went with the spray foam. I went with 1" thick spray foam to really seal up the shop. With the girts, and the 6x6" posts I had more than enough room for the spray foam, and then batts. I wanted batts so I could easily run wires in the future if I ever needed to. Plus for ease of installation.

The spray foam really tightened up the shop, and made it quieter inside. I've got the foam, then R-19 batts, and now drywall. With a torpedo heater I can keep it at 70 degrees really easily. I know as we had to do that for the mud on the drywall to dry.

Once I put in the ceiling with R-30 sprayed in, I know this shop will really hold temperature well. I'm excited.

Location: Nashville, TN

wow. All that for Tennessee?

 

[haugy]

Location: Nashville, TN

wow. All that for Tennessee?

Yeah, I know. But it was 9 degrees for a good part of winter last year. Plus I want to ensure that in the 100 degrees I can still work on my projects in the air conditioned space. Some of my projects are old. Another one is a boat so I wanted to ensure I could also control the humidity.

I'm known for going overkill. But I figure if I'm going to do it, do it right.

 

[green.bubbly]

I am in Lafayette as well and will be building a pole barn for use as a camp on Toledo Bend. If it goes well I may build my next house this way too. I know of a planned pole barn house that will be built in Eagan.

This is exactly what I am thinking of. Will the bubble wrap (being snug up against the metal beacuse of the foam) inhibit its ability to stop condensation? Will the foam up against the bubble wrap cause the foam to loose its "making the building more rigid" qualities as well as be less effective against air leaks? Should I just forget about this method and pay for the CC foam?

I was looking at getting a pole barn built as a home but the open span roof is what made me go with steel. Pole barns require attic trusses and the best I could do is get a slightly vaulted ceiling. I will have a second floor craft room for my wife and the open ceiling of a steel building was my obvious choice.

I spoke to an insulation contractor last week. He suggested to order the building with no insulation or foil/bubble wrap. Everything would be sprayed and covered should creating a thermal break was not necessary.

Who are you planning on getting your pole barn from or are you planning on doing it yourself? I ask because I had very poor response from the people in Iowa, La. I called to discuss the truss options and after two weeks and several calls to them, I was still waiting for a call back.

I was repeatedly told that the truss guy was on a job in Texas. Crappy excuse or just poor customer service. Surely he had a mobile phone??? I even told them that I would not mind a call at night. I then sent an email to the owner explaining the lack of a response and have had no reply. I called back last week to basically tell them that they can kiss my business good bye. Some sales rep was very apologetic and we ended deciding that a pole barn would not work due to the trusses.

Let me know when the camp is done and I will be happy to give it a good weekend inspection for you at no charge.

 

[HetrickElectric]

Just to chime back in here on my thread.

I went with the spray foam. I went with 1" thick spray foam to really seal up the shop. With the girts, and the 6x6" posts I had more than enough room for the spray foam, and then batts. I wanted batts so I could easily run wires in the future if I ever needed to. Plus for ease of installation.

The spray foam really tightened up the shop, and made it quieter inside. I've got the foam, then R-19 batts, and now drywall. With a torpedo heater I can keep it at 70 degrees really easily. I know as we had to do that for the mud on the drywall to dry.

Once I put in the ceiling with R-30 sprayed in, I know this shop will really hold temperature well. I'm excited.

Did you use open or closed cell? Sorry if I missed this answer somewhere.

 

[haugy]

Did you use open or closed cell? Sorry if I missed this answer somewhere.

My bad. 1" closed cell foam

 

[kbkna]

Mind if i ask what you paid per foot? I am in the process of getting bids here in Alabama.