For the sidewalks here is what I'm thinking. Buy enough spray kits to spray all along the green treat and steel at bottom, as well as up and down every post to seal those void areas. A local company can cut me vinyl batt insulation to fit between posts (roughly 7'8"). This should seal up sidewall well, still in debate on ceiling.
Spray foaming shop?
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Seasoned Oak
Minister of Fire
Have to disagree on that. fibreglass insulation with gaps all around it provides practically no insulation value at all. The cold simply goes around the insulation. Improperly intalled fibreglass is a waste of materials. It is very difficult to get it 100% tight which is why i use blown in cellulose. IV been insulating for 30 years of rehabbing old houses.
Seasoned Oak
Minister of Fire
Have to disagree on that. fibreglass insulation with gaps all around it provides practically no insulation value at all. The cold simply goes around the insulation. Improperly intalled fibreglass is a waste of materials. It is very difficult to get it 100% tight which is why i use blown in cellulose. IV been insulating for 30 years of rehabbing old houses.
Seasoned Oak
Minister of Fire
I have to agree with that. Fibreglass is almost impossible to get perfectly around electrical boxes and wire and tight against the studs. Cellulose is far superior in that respect.
Highbeam
Minister of Fire
I found a couple of examples of blown in wall cellulose. I haven't done it though. Perhaps you can offer your experiences in this relatively rare method? Specifically, in a pole barn with 8 foot framing member spacing?
The R-value of a material is a material property. It is independent of how you install it or use the R-value. To get a finished wall system to perform at a particular R-value you have to apply the materials properly which might be difficult or impossible. I think you misunderstood my statement OAK, the FG batt has an R-value that is the same at the store as it is in the wall. If as you say, the installer screws up, that R-value won't be able to prevent heat loss from the conditioned space to the outside. That's not the fault of the material but of a bad installation.
I sticked out the 12' wide bays between my poles for insulation, wall sheathing, and other reasons. It is not a structural wall supporting the roof or anything but it was done well. It is surprisingly cheap to buy the lumber for this and skill required is relatively low. You already have girts wrapping the outside of the poles, another method is to add girts to the inside just nailed to the face of the posts. This will provide a framed out wall cavity and also a place to attach interior sheathing. Then you could dump loose insulation into the cavity or even set in batts.
I've been having sex for almost thirty years but that doesn't mean I'm doing it right.
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Fiberglass is a marketers dream, sounds great on paper but real world its just not very effective. I dont care how good you are you cant make it fit perfect around electrical. Theres going to be small gaps, theres going to be places where its compressed. Thats why i made the statement about losing close to 30% of the rated r value. Real world vs lab tested are two totally different things.
To do blown in cellulose here i would tack 6mil fiber stranded poly to the posts as a temperary wall, and blow in from the top inbetween the the headers. that gives you 5.5 inches of cellulose which would give you roughly r18. That fiberstranded poly is very tear resistant and relatively cheap.
To do blown in cellulose here i would tack 6mil fiber stranded poly to the posts as a temperary wall, and blow in from the top inbetween the the headers. that gives you 5.5 inches of cellulose which would give you roughly r18. That fiberstranded poly is very tear resistant and relatively cheap.
http://www.homedepot.com/p/Americov...lyethylene-Construction-Film-PSR620/203635224
Can be found cheaper other places online or at a local wholesaler
Can be found cheaper other places online or at a local wholesaler
I've tried out a few different heat loss calculators on my primarily fiberglass-insulated house, and my heating consumption seems to agree pretty well with the predicted values.
Between the theory that you lose huge amounts of heat around the edges of the kraft paper, and my real world experience, I lean towards what I see on my energy bill.
Buzz Saw
Minister of Fire
FWIW I would consider framing out and sheeting the bottom 8 or 10 feet. That way you protect your investment and have a place for workbenches or hang a shovel without messing up the insulation.
Really enjoying this thread. I'm looking to insulate a 40x60 in the Spring and I've been trying to figure out the best method.
The 6 mil poly sounds easy but at 18 ft I feel like I'd be blowing in more every year for a long time as it would continue to settle. Just an assumption not totally familiar with the product.
Buzz Saw
Minister of Fire
When I remodel my last house the insulation guy blew in cellulose with the walls open. The cellulose was sprayed in using a water mist. That stuff packed in so tight there was no place for it to settle. Now I don't know if that would work in a barn without studs. In my case I'm going to stud it out to sheet the walls.
Seasoned Oak
Minister of Fire
I kind of learned by trail and error. Years after i insulated my house i thought i forgot to do the bathroom as it was the coldest room in the house despite having hot water baseboard running the whole length of the out side wall. Turned out it was the only room i did with fibreglass , the rest of the house was done with blown in. Doesnt really matter what the R value of the insulation is if it cannot or does not provide air sealing as well. Its also hard to tell if the blown in went in 100% if you dont know if theres fire stops n the wall or havn't opened the wall in old applications. Iv used both and all i can say from my experience is fibreglass is a waste of time and money for what i do. In new construction it a little easier to get it tighter but you still have wires to deal with.
Seasoned Oak
Minister of Fire
The machine I use is a krendl 2000, which has a greater capacity then the ones at Home Depot that come free when u purchase the 10 bags but it's the same concept just don't work as well but still good enough to do this. You just have to adjust the air to product ratio accordingly. It will settle but if u did it now it'd be fine for this winter, then maybe touch it up once before next winter after its had a year to settle... It's not going to settle a crazy amout, it'll stay up there pretty good but it might a little and in my eyes you can't beat what'd u be getting on a budget. Buy 10 more bags next fall touch up what settled and blow the rest in ur ceiling....then if your budget changes and you're sick of looking at the poly just put the 29 gauge metal over it.
semipro
Minister of Fire
The options I'd suggest for the walls in no particular order:
I don't recommend DIY spray foam because of the cost. Comparison here: https://www.hearth.com/talk/threads/wall-insulation-looking-for-opinions.146629/#post-1974728
In my experience fiberglass is very hard to install properly and requires a separate air barrier. In many cases it ends up acting as an air filter and home to vermin.
I've heard from numerous sources that you can often hire an insulating contractor to do the job for less than a DIYer can buy the materials.
- Contractor-sprayed foam to desired R-value
- Contractor-sprayed thin foam with additional fiber insulation (flash and batt/fill)
- Foam boards to desired r-value, sealed at seams and edges (XPS or polyiso)
- Dense-packed cellulose
- Some combination of above
I don't recommend DIY spray foam because of the cost. Comparison here: https://www.hearth.com/talk/threads/wall-insulation-looking-for-opinions.146629/#post-1974728
In my experience fiberglass is very hard to install properly and requires a separate air barrier. In many cases it ends up acting as an air filter and home to vermin.
I've heard from numerous sources that you can often hire an insulating contractor to do the job for less than a DIYer can buy the materials.
You're going to be hard pressed finding a contractor spraying less than an inch. For a pole barn that big that doesn't involve a lot of prep work and clean up you might find someone to bid reasonably at .85 cents depending on your area.... I've never seen closed cell in the small tank kits at less than a dollar a board foot and my wholesaler offers us very good pricing because of the amount of material we get from them... 71 cents a board foot sounds more like open cell which is r3 an inch compared to r6 for closed cell small kits. The real stuff we get in 55 gallon drums that you need a proportioner is up to around r7.2 an inch now.
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Highbeam
Minister of Fire
So let me get this straight. You have 6x6 poles 8 feet apart making a wall 18 feet tall. Flat girts on the outside 24" OC with metal siding screwed to it. The proposal is to staple visqueen to the inside face of the poles? What about the bottom? Won't the insulation just fall onto the slab or out of the ribs on the outside, do you really want cellulose insulation setting on the uninsulated slab where water is likely to be present from the trucks being pulled in?
Assuming you seal the bottom somehow, then you blow in loose cellulose from the top. You can see it fill and monitor settlement through the clear visqueen, cool. I expect there to be a bulge on the plastic towards the inside in the middle. Maybe a pretty big bulge, especially over time as things settle. If your staples let go on that post, bad mess. I would suggest some sort of strapping board nailed to the post to clamp the plastic sheet tightly to the post.
Then what? You can't add metal or other sheathing to this wall since there is no framing and also that bulge. To remove this plastic/cellulose system to do something else is a huge mess. An explosion of loose fill cellulose will hit the floor when you try to remove it. You could fill several dump trucks with this quantity of waste insulation.
How about this addition. Plastic as described above but before blowing in the loose fill, nail 2x4 girts to the inside of the poles horizontally every 24" OC. This is not expensive and will keep the cellulose bulge within the wall cavity, give you something to nail sheathing to, and make this investment a more permanent solution.
If you ever have to remove a metal panel on the outside you will drain the cavity. Be ready. I also worry about the walls resistance to bulging from this loose insulation. Those bales of insulation get heavy. Over time they will tend to settle and densify at the bottom like any liquid will and exert pressure in all directions. Can the metal panels/girts hold that back? I don't know.
I would consider that wet blown cellulose before this whole plastic scheme. The wet blown is like a solid fill and won't settle or bulge panels inside or out. You do need a contractor though.
No you couldn't remove the metal panels with this method but there's answers to all those problems but I'm sure they'll be picked apart one by one... I dont know what answer is wanted here. Foams too expensive, framing isn't an option, cellulose method you can't do this and this or that might happen.... I don't no what to tell you. Doesn't sound like any things going to work then. I'm just spit firing ideas to help.
Never said that idea was the best, just trying to come up with an idea that was cheap and in the end just an idea.
Never said that idea was the best, just trying to come up with an idea that was cheap and in the end just an idea.
I just started looking into this topic myself so i will be following this thread. w hat iv'e gathered is that foam board doesnt' insulate well, but is dirt cheap. spray foam insulates but is very pricey. fiberglass batting takes some work, but has a good R factor and is cheap. so far it's looking like fiberglass form e.
Highbeam
Minister of Fire
Foam board insulates very well but is actually pretty expensive and requires lots of labor and then sealing up with at least a small amount of Great Stuff type foam around the edges. It's not a bad way to go in this pole barn application because the bays are wide open, regular shapes, and are backed with 2x6 girts that you can use to fasten the foam boards.
I insulated under and around my slab with 2" of foam. I bought it at the factory and it was still pretty pricey. No other option though for underslab.
For the OP, I just can't imagine a situation where not sheathing the walls on top of whatever insulation you choose will be wise. Seems all insulation types are all prone to damage or present a fire danger when left naked. I also don't know of any sheathing method that doesn't require some sort of framing, at least the face girts. So you may as well take advantage of the sheathing framing and use it to help you insulate.
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Buzz Saw
Minister of Fire
The contractor that did my wet blown cellulose dud it cheaper,materials & labor, than I could buy just the material.
Two guys and 10 hours later they were done. The only mess they left behind was the usual dust that comes along with cellulose.
After 3-4 days of drying the walls were drywalled. I loved the stuff. Too bad the guy retired. [emoji20]
Highbeam
Minister of Fire
Please stick around and help. There are others following this thread too and we can all learn from your experience. Each method, and there are several and even some clever ones, have plusses and minuses. If you have the cash, the spray foam is ideal.
It's one of those cheap, good, and fast situations where you can only have two.
Highbeam
Minister of Fire
Oh and for wires with FG batts, if you are anal like me and willing to take the time, you simply split the batt the long way and weave the back of the batt behin the wire and the front of the batt in front of it. They join right back up below the wire and make a perfect seal. Cutting around J-boxes is way harder but taking your time you can make it work there too. Also realize that each of these potential imperfections are extremely small deals compared to the entire wall system. It doesn't ruin the R-value of the rest of the wall if one little square inch has no insulation behind the sealed VB. It doesn't need to be 100% perfect.
My plan has always been to do 2x4 girt with 8ft steel around inside question is at what point based on insulation strategy. The idea of filling that cavity would be effective and reasonable I do believe. The concern of moisture under there could be an issue. Rolling cut-to-fit vinyl back fg batt from top down to 8 ft may look the best at that point.
Local contractor quoted $2 sq ft at 2 inch to do spray foam. Easily be 15k+
Local contractor quoted $2 sq ft at 2 inch to do spray foam. Easily be 15k+
Insulating a large barn that's 5000sqft with 18ft sidewalls isn't going to be cheap no matter what. This is a huge project and waiting until you have the funds to do it right is some times the best option..... It's hard for us to give the best advice because we don't know what the real obstacles and real goals are for your personal situation. Is this a down and dirty pole barn where we're just trying to keep a little heat, or is this going to be a nice shop where its being heated 24/7 and want it to look nice inside. Everyone has a different definition of "shop" and "tight budget" we don't know the real financial situation that exists because it's not "ours." the best we can do is offer a wide variety of solutions and hope one sticks to your needs and goals
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