Another pole barn ceiling insulation thread

[b-boy]

I've read through a few, but I was hoping for some ideas specific to my project.

I just built a 30x40 pole barn. I have 12ft ceilings. It's metal walls and roof. There is no insulation in place yet. I went with regular trusses.

I'm looking to bring in utilities, so I need to insulate and heat the interior.

Here's my plan:
2" foamboard glued/screwed to the wall girts. Follow that up with spray foam (great stuff) to seal off any gaps in the foam. This should give me R10, plus a vapor barrier.

3 1/2" unfaced insulation in front of the foam board. This will give me an addition R11. This will fill the gaps between the posts.

I'm on the fence about building 12-ft framed walls beteeen the posts, or just run horizontal 2X4s and nail into the posts. This would provide nailing points for OSB, as well as keep the insulation in place. This would be run up to the top plate.

OSB attached to the walls all the way up to the joists.

Here's where I'm stuck:
I'm unsure of how to do the ceiling. The joists are 48" OC. I have corrugated steel panels for the ceiling, so I'll be screwing those up once the insulation is in place. I'm planning on using R30 to unsulate the ceiling.

Do I:
1) Run 1x3s perpendicular to the joists every 24". Then fill the voids between the joists with 48" wide kraft-faced insulation?
2) Run 1x3s perpendicular to the joists every 24". Then fill the voids between the joists with 48" wide unfaced insulation followed by a plastic vapor barrier?
3) Is there a way to attach 48" wide insulation to the celing without adding the 1x3s for support?
4) I've also considered blow-in insulation, but I haven't even priced it out yet.

What's the best way to insulate the ceiling? Are there other ways I should consider?

 

[lakeroadster]

Go with #4

Ceiling: Put the steel up, perpendicular to the joists. Seal the steel seams with mastic tape or duct tape the seams from the attic side.

When you are done installing the steel blow insulation on top of the steel.

The tape keeps the insulation from working it's way through the seams of the steel.

What is your location?

Walls: If you have a floating slab it's best not to put the wall covering (OSB) against the slab. The slab, by design, moves independent of the walls. Sometimes the movement can be significant, sometimes minimal.

Use the same technique as floating walls in a basement in regard to the closure at the slab to wall interface. Google "floating wall".

 

[bullnerd]

Maybe you can get some ideas from my build in my sig.

I copied what Morton buildings does.

To me, stick framing in between the poles is a waste, I used blanket insulation.

I also didn't want anything touching the steel anywhere.

My ceiling is done, I'm working on the walls now. When they are done It will get blown-in the ceiling.

 

[Highbeam]

Don't screw with foam, you can get R19 with regular fiberglass batts. VB with plastic sheet on the inside or faced insulation. All of that effort and cost for foam doesn't get you much improvement at all.

I have a pole barn too. Outside of girts is wrapped with tyvek then metal. Inside of girts I stick framed, attached R19 faced batts, and covered with OSB.

In my pole barn the trusses are 12' apart so I installed ceiling joists between them with joist hangers and then 6 mill poly, and then screwed the metal to the joists. Then I blew in R50 of cellulose from above. Very nice way to go.

 

[lakeroadster]

To me, stick framing in between the poles is a waste, I used blanket insulation.

Unless you want to hang cabinets on the walls.... or other such heavy items.

Really just depends on what your plans are for the space.

 

[Radix2]

Where are you located?

I have 24" oc trusses.

The metal panels are fastened every other truss...so you are good to go with your 48" spacing.

Just put up the metal and blow cellulose on top. I did not seal the metal from above and there is no insulation leakage, the overlaps are plenty tight.

Blown in insulation is far easier and far superior to blankets since it will fill much better around all the truss members and nooks and crannies. A good installer will be almost as cheap as buying the material yourself.

Get get ceiling up and write a check on this one, you deserve a break!

 

[86turbodsl]

Blow in cellulose in the ceiling at least. Nothing else comes close for the price. It's what i'm doing and i priced everything out.

 

[b-boy]

I'm in Buffalo, NY. We get a lot of wind, rain, and obviously snow.

I figured that the foam board, if properly sealed up, would do a good job of eliminating air infiltration. I've already purchased the foam board, so I'm going to stick with that.

As far as framing, I do plan on hanging cabinets. Does anyone see a problem hanging them on horizontal 2x4s screwed into the posts? Will they hold up? My posts are 8' OC.

Consensus seems to be blow-in insulation. That was my original plan, but I thought batts might be somewhat cheaper. Do I use a vapor barrier under the steel panels, then blow insulation on top of that? Is this something I could do myself, or should I just hire someone? I'm pretty self sufficient, but sometimes it's just easier to farm it out.

For blow-in insulation, do I just leave 1 panel off, so the contractor can get into the space? I'm not sure what type of access is needed to the area above the ceiling.

 

[lakeroadster]

As far as framing, I do plan on hanging cabinets. Does anyone see a problem hanging them on horizontal 2x4s screwed into the posts? Will they hold up?

What's the post spacing? How heavy are the cabinets?

Here's how I did the wall in my barn where the cabinets are. I had the luxury of T-Girts on this wall (2x6 girt with 2x4 stiffeners nailed to the girts). There's a lot more information in my build thread, starts at post #269 here: Barn West Cabinet Wall


____________________________________________________________________________
Without T-girts... if you want a really strong wall, here's an option. See post #15 here Interior Perimeter Wall Design

 

[b-boy]

If you're talking about those 45 degree cross members, I do have a pair of those on each wall near the corners of the building.

Posts are 8' apart. I'll most likely hang basic kitchen cabinets. They'll probably contain tools, cleaning supplies, etc... Nothing heavier that you'd find in a kitchen.

 

[b-boy]

It's interesting to me how many different ways pole barns are constructed. Every picture I see has a slightly different build technique. I used to think these things were pretty 'boiler plate'.

 

[lakeroadster]

If you're talking about those 45 degree cross members, I do have a pair of those on each wall near the corners of the building.

Posts are 8' apart. I'll most likely hang basic kitchen cabinets. They'll probably contain tools, cleaning supplies, etc... Nothing heavier that you'd find in a kitchen.

Not the 45 degree members in the corners of the barn... those are there to prevent racking.

Girts are the 2x6's that go from column to column, what the siding screws to.

A T-Girt is the regular 2x6 Girt that has an additional 2x4 nailed to it. This stiffens the girt significantly for wind loads (see attachment below). T-Girts are typically only used if the building support columns are widely spaced and if the barn is located in an area with high wind loads.

For a cabinet wall, when you tie all the T-Girts together that span between 2 columns using vertical 2x4 stud's, then sheath the front with plywood, the entire wall transfers the cabinet loads to the building support columns quite well without touching the building slab.

If you don't have T-girts you need a way to transfer the weight of the cabinets over to the building support columns. That's why the wall you benefits from those angled members shown above.

 

[bullnerd]

Unless you want to hang cabinets on the walls.... or other such heavy items.

Really just depends on what your plans are for the space.

I agree.

I used structural fasteners to hold the 2x4 girts to the posts, so hopefully they will hold something, I don't know what yet though. I used 16'ers and overlapped them on the 8' posts.

 

[Firebrick43]

Lake roadsters t girt wall is complete overkill to hang cabinets. Good job.

I personally think placing girts/purlins between post instead of outside is crazy just to save a few inches with few advantages.

First use structural screws to put up purlins where you are hanging cabinets. Line up the inside and outside purlins. Take the one that will be near the top and another near the bottom of the cabinets. Now slide a 2x6 or whatever thickness your post is and screw it between the two purlins. This should be done before outside sheathing and makes a strong I beam. Even better would be to glue/screw a piece of osb/ply to the bottom and top of both inside and outside purlins. This creates an extremely strong box beam using scrap strips from cut off pieces of osb.

I just don't see why framing a whole wall when the load is in one specific height of the wall.

 

[lakeroadster]

I personally think placing girts/purlins between post instead of outside is crazy just to save a few inches with few advantages.

Opinions vary. On my barn all the girts and purlins are attached to columns and trusses using heavy Simpson hangers and Simpson structural screws... it's crazy strong compared to nails that split the wood due to nailing so close to the end of the boards..

Purlin: A horizontal beam along the length of a roof, resting on a main rafter and supporting the common rafters or boards.

Girt: A horizontal structural member of post and beam architecture, typically attached to bridge two or more vertical members such as corner posts.

 

[Firebrick43]

Opinions vary. On my barn all the girts and purlins are attached to columns and trusses using heavy Simpson hangers and Simpson structural screws... it's crazy strong compared to nails that split the wood due to nailing so close to the end of the boards..

Purlin: A horizontal beam along the length of a roof, resting on a main rafter and supporting the common rafters or boards.

Girt: A horizontal structural member of post and beam architecture, typically attached to bridge two or more vertical members such as corner posts.

Not questioning the strength of your set up, it's overkill no doubt. I however think from a strength to cost or a strength to weight ratio it scores real low. Also tons of thermal bridging.

The concern of ends of girts splitting is a non issue if you use purlins that span more than 2 post and stagger the joints so all the girts ends don't end on the same post. Also most structual screws self drill or you can predrill screw holes to eliminate spliting entirely. As for the Simpson strong tie connecter the take vertical loads very well, no doubt about it,but they do not transfer tension loads very well at all, therefore girts on the outside if applied as I mentioned before are going to have greater shear strength. To transfer shear/tension loads with Simpson strong tie you have to add strapping with adds even more cost. Plus is see some toenailing/splitting in your picture on the bookshelf girt?

Then when your apply the sheathing it ties it all together anyways, making a few split ends s non issue. Sheathing takes all the vertical weight loads as well so the vertical members you placed are free loading. You have to look at a wall as a whole system.

Making a box beam with scrap osb is very cheap. It also is the strongest option (due to the simple fact it has more depth) to deal with the cantilevered loads that cabinets add. It also has the least thermal bridging due to the extremely low cross section of material running from the outside to inside.

The biggest advantage to a wall as you built it is one simply doesn't have to think about where cantilever loads will be placed on the wall.

Sorry about the girts/purlins. I know the difference but unfortunately 25 years of the locals here calling them all purlins has affected me as well. Using the word girt will just get you confused looks around here.

 

[b-boy]

I do have one post to post span of 10' on the 30' end of my building. Everywhere else it's 8 ft. I'll have to do some reinforcement there I guess. Especially if I plan on hanging cabinets.

Anyone have any cost estimates on blown-in insulation for ~1200 feet ceiling @ ~R30. I know it's impossible to get a real number. I'm just looking for ballpark.

I just spoke to my contractor about running utilities to the building. It was a little more than I thought it would be, so I might need to cut some costs elsewhere.

He quoted $4200 to run a 2" conduit for electrical, a 1" conduit for communication, a 1" water line, and a 1" gas line. He'll hook up the water and gas, but he won't pull wire. The building is about 150 ft from my house.

 

[bullnerd]

4200 is not bad. My electric guy wants 39 something just to run electric and mount the pan.

I think I got quotes around 1500 plus or minus for the blown in. I can look it up.

I have about the same sq/ft.

 

[Dragfluid]

Didn't you say that you're in NY? Then why only R30 up above??
You need twice that. Don't shortcut on insulation.

 

[stm317]

There are guides on most cellulose packages that will tell you the required depth and coverage in sqft per bag at the given R Value.
R30 is pretty low for New York. R60ish is recommended in my part of central Indiana, and it likely gets just as cold or colder where you are. Cellulose needs to be about 15 inches to get that R 60 value.
There are also quite a few online calculators for this sort of thing: https://www.insulationmachines.net/tips-and-tricks/cellulose-and-fiberglass-coverage-calculator/

 

[b-boy]

Thanks. I was relying on a US map I saw online somewhere. It showed recommended R values by region. I'll have to do some more research.

 

[b-boy]

My eyes are ****. I took another look and the map says 38-58, not 30-50. That's what I get for not wearing my reading glasses.

Good thing I posted here first.

 

[b-boy]

I've been reading up on cellulose. A few people seem to think it's a fire hazard over the long term. Basically, that the fire retarders added wear out after many years. Anyone have any insight on this?

 

[4cyclic]

I used 2x4’s screwed in to the rafters 24in spacing, then poly 6 thou, finally metal liner attached to the 2x4. On top 18in blown-in cellulose. The 2x4’s give you a lot more surface to screw the liner to.

 

[Highbeam]

I've been reading up on cellulose. A few people seem to think it's a fire hazard over the long term. Basically, that the fire retarders added wear out after many years. Anyone have any insight on this?

It doesn't burst into flames. Even if you assume that the retardant wears out your insulation will then be no more flammable than all the lumber. Non-issue.

The real issue with cellulose is if it gets wet from a roof leak. Ick. It's just shredded paper and if you've ever made paper mach'e.

The cellulose is the best thing out there right now. It air seals well, is cheap, easy to blow DIY with a machine from the home depot. My wife and I blew 15" deep cellulose into my pole barn attic. It took a lot of bags, goggles and respirators for both the machine loader and the blower.

 

[b-boy]

OK, but shredded paper and lumber have very different levels of flammability. I can hold a blow torch to a piece of lumber and it will take a long time to catch on fire. Paper, on the other hand, will go up in an instant. Most electrical fires are caused by debris between the walls catching fire, not the lumber.

In any case, the stuff I was reading mentioned 20-25 years before this becomes an issue. I'm almost 60, so I'm not going to worry about it too much. By the time it burns down, I'll be too old to care.

This is probably a stupid question, but how do you finish the job? Isn't there a spot that you can't reach when you're done.

You have to have an access hole into the ceiling area, so how do you finish off the area above the access hole once you cover it? I've been to a bunch of website, but nobody talks about that.

 

[Dragfluid]

"so how do you finish off the area above the access hole once you cover it? "

Secure some fiberglass to top of the cover. Or make a 20" high frame around the top of the cover and fill it with cellulose. That would be fairly heavy though.

 

[bullnerd]

I'm going to frame a rim like mentioned and attach rigid foam to the backside of the door/cover/hatch/thingy. My cover will be screwed on so it blends in. Wont be going up there much.

 

[b-boy]

OK - I guess that will work. I'll probably build a frame around the area, fill up to that point, then get a large piece of fiberglass to sit on the panel. My panel will be screwed in place as well. Once the insulation is in place, I won't be going up there again. The joists are 4 feet apart, and I'm not a gazelle.

 

[Radix2]

OK, but shredded paper and lumber have very different levels of flammability. I can hold a blow torch to a piece of lumber and it will take a long time to catch on fire. Paper, on the other hand, will go up in an instant. Most electrical fires are caused by debris between the walls catching fire, not the lumber.

In any case, the stuff I was reading mentioned 20-25 years before this becomes an issue. I'm almost 60, so I'm not going to worry about it too much. By the time it burns down, I'll be too old to care.

This is probably a stupid question, but how do you finish the job? Isn't there a spot that you can't reach when you're done.

You have to have an access hole into the ceiling area, so how do you finish off the area above the access hole once you cover it? I've been to a bunch of website, but nobody talks about that.

I've never seen any credible study explaining how the borates in cellulose are supposed to "wear out" ...

There are, however, several studies that show cellulose is superior to Fiberglas in a fire - the combination of it as a class 1 fire retardant and the fact that it does not allow airflow like fiberglass makes sense .... http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=8afbee94-909f-40e4-85d0-4c860a8533b6

The fiberglass companies have been trying to smear cellulose for years.. at this point, there are so many studies that show cellulose is superior for most applications that nobody should be fooled.

 

[b-boy]

Honestly, price-wise it seems like the way to go for me. If I could afford foam, I'd go that route, but I can't.

 

[bullnerd]

"I'm not a gazelle"- Muhahaha ! I hear ya!

 

[Dragfluid]

OK - I guess that will work. I'll probably build a frame around the area, fill up to that point, then get a large piece of fiberglass to sit on the panel. My panel will be screwed in place as well. Once the insulation is in place, I won't be going up there again. The joists are 4 feet apart, and I'm not a gazelle.

My trusses are 8' apart, and I don't pole vault.
Look at my build thread for the nice catwalk.

 

[OregonAreaMan]

I want to revive this thread with a question regarding my OSB pole-barn ceiling. My ceiling is low, making it impossible to make an attic to blow in insulation. My purlins are only 12" apart on center. I have been told I can put fiberglass batts up there and that I won't have issues with moisture as long as I leave them exposed to breathe. Any recommendations? Currently considering fiberglass with a fabric cover over the surface. I'd like to avoid the spray foam because I have had leaks I recently fixed. Located in Southern Oregon.