Critique Needed for Walls and Insulation Plan (Pole Barn)

[GRivera]

I want to insulate and finish the interior of my pole barn using OSB on the walls and white metal panels on the ceiling. I need a critique on my plan. The pole barn is 30x40’, 12’ walls, and scissor trusses. The roof pitch is 4/12 and inside ceiling pitch is 2/12. The builder installed bubble wrap between the roof panels and the trusses. Poles are generally 8’ OC (some closer) and trusses are 4’ OC.

Plan:

Walls
• Staple Tyvek between posts to inside of girts to act as vapor barrier
• Add vertical 2x4 framing with treated base plate, between posts for stability of OSB
• Install faced R19 batt insulation on walls
• Install 1/2” OSB horizontally, off-set seams. Not touching concrete floor

Ceiling
• Install R30 batt insulation between bottom of trusses using straps to hold in place
• Staple Tyvek to bottom of trusses for vapor barrier
• Install metal panels perpendicular to trusses

Does this sound like a good plan?

I am undecided on electrical hidden or conduit but leaning toward surface mounted box with conduit for inside. Outside lights and GFI outlets to be wired within walls after Tyvek

I plan to install a 2-post lift eventually

I may paint the OSB in white

 

[GRivera]

Anyone?

 

[Firebrick43]

I am completely baffled. Why tyvek on the inside????

Pole barn has metal siding? Did you put a vapor barrier on the outside? Inside vapor barrier is 6mil visqueen taped with red barrier tape. Tyvek is not a vapor barrier. It's a wind barrier that allows vapor diffusion. The wind barrier part is ok (plastic does as well) but you do NOT want the vapor diffusion. On the inside, you want the opposite. Tyvek goes to the outside of a wall and in a metal vertical sided building tyvek is unnecessary.

As for the walls I am unsure why this idea of vertically building stud walls between post is so prevelent but is wasteful of materials and labor. Face mounted girts will "stabilize" the OSB just fine. Use screws instead of nails for the girts and some decent loads can be hung from the wall. For really big cantilever loads such as wall mounted cabinets or tire racks place a bookshelf gift between the outside and inside girt using construction adheasive and screws and it will be stronger than a stud wall. Remember the OSB panel (or steel) will hold the weight in the vertical orientation. Don't fight that.

Then use a continuous fiberglass blanket the width between poles hung from the headers. This is much more efficient thermally and labor/material wise. The blankets are available from insulation supply houses and Menards but I doubt you have Menards in your area.

If you want to still waste money and have worse thermal performance with a vertical studded wall do NOT put a sill down on the concrete floor. A floor in a pole building(if it's truely a pole building) will move independently of the poles and should never be keyed or tied together. It will end up in poles being jacked out of the ground during freeze and thaw cycles. I have seen several that it has happened to over the years. Leave a 1" gap and fill with a thick closed cell foam that compressible.

Also I sort of understand OSB on walls but if your going to paint it "WHY"? Liner is just as cheap as OSB especially with current prices(of OSB) once you paint it and it will never be as well lit as white metal.

Surface mounted emt is a personal preference, one that I would do, but please get a benfield type bender and jack benfields book so you can learn to bend it properly and especially make offset bends. Nothing looks like hack work than offset emt connectors and 90 fittings instead of nice bends. Bending emt is a lot cheaper than fitting to boot.

 

[Astross89]

I am completely baffled. Why tyvek on the inside????

Pole barn has metal siding? Did you put a vapor barrier on the outside? Inside vapor barrier is 6mil visqueen taped with red barrier tape. Tyvek is not a vapor barrier. It's a wind barrier that allows vapor diffusion. The wind barrier part is ok (plastic does as well) but you do NOT want the vapor diffusion. On the inside, you want the opposite. Tyvek goes to the outside of a wall and in a metal vertical sided building tyvek is unnecessary.

As for the walls I am unsure why this idea of vertically building stud walls between post is so prevelent but is wasteful of materials and labor. Face mounted girts will "stabilize" the OSB just fine. Use screws instead of nails for the girts and some decent loads can be hung from the wall. For really big cantilever loads such as wall mounted cabinets or tire racks place a bookshelf gift between the outside and inside girt using construction adheasive and screws and it will be stronger than a stud wall. Remember the OSB panel (or steel) will hold the weight in the vertical orientation. Don't fight that.

Then use a continuous fiberglass blanket the width between poles hung from the headers. This is much more efficient thermally and labor/material wise. The blankets are available from insulation supply houses and Menards but I doubt you have Menards in your area.

If you want to still waste money and have worse thermal performance with a vertical studded wall do NOT put a sill down on the concrete floor. A floor in a pole building(if it's truely a pole building) will move independently of the poles and should never be keyed or tied together. It will end up in poles being jacked out of the ground during freeze and thaw cycles. I have seen several that it has happened to over the years. Leave a 1" gap and fill with a thick closed cell foam that compressible.

Also I sort of understand OSB on walls but if your going to paint it "WHY"? Liner is just as cheap as OSB especially with current prices(of OSB) once you paint it and it will never be as well lit as white metal.

Surface mounted emt is a personal preference, one that I would do, but please get a benfield type bender and jack benfields book so you can learn to bend it properly and especially make offset bends. Nothing looks like hack work than offset emt connectors and 90 fittings instead of nice bends. Bending emt is a lot cheaper than fitting to boot.

When you say liner is the same price as osb. Do you have a link to a product? Not sure what type of material you're talking about. Thank you

 

[GRivera]

Thanks for the honest critique. The Tyvek idea was only because a friend has offered me a roll for free - I will do the plastic as a vapor barrier instead.

I am also glad you referenced the inside girt idea. I had gone back and forth on this and if a sill plate is a potential issue I will heed the advice. Seems the girts will be easier as well.

 

[Firebrick43]

When you say liner is the same price as osb. Do you have a link to a product? Not sure what type of material you're talking about. Thank you

https://www.menards.com/main/skusummary.html?primaryMeas=96.0&secondaryMeas=36.0&pid=1444448673649&cid=5717

If I do a 36" wide by 96" long it's 16.19
Regular price (14.68 right now). 16.19 divided by 24 square feet is ~$0.68 square foot

1/2 OSB is $15.85 at my Menards right now. 15.85 divided by 32 equals $0.50 a square foot but then you will need a coat of kiltz to keep the glue from bleeding through and two coat of paint (OSB will obsorb a lot) you are going to equal if not surpass the OSB $0.18 price difference plus all the extra labor needed.

 

[Astross89]

Thank you

 

[GRivera]

I may just leave the OSB natural. How difficult is it to master the art of bending the EMT?

 

[stm317]

I have a similar building (32 X 48 X 10 with scissor trusses) and have a similar overall plan.
If you're going with rolled insulation in the ceiling, I'd look for the kind that comes wrapped in plastic. That would let you avoid the separate vapor barrier in the ceiling, and it would protect the insulation on all sides from condensation forming or dripping down onto it.
Something like this:

It may even be reflective enough as-is, and let you avoid the metal on the roof.

 

[lakeroadster]

Does this sound like a good plan?

Opinions vary. There are a lot of ways to skin this cat.

Blankets hung from the header won't work very well after bookshelf girts have been added. Basically the bookshelf girts are no different than a stud wall, a floating stud wall.

Stud walls have their place, they just shouldn't be built down the the floor, they should be floating stud walls, which is certainly not a new technique. Floating walls have been discussed here on TGJ many times.

If you're wanting a floating stud wall sub-structure here's how I did mine. See thread 142 here: https://talk.classicparts.com/threads/lakeroadsters-high-country-barn.22110/page-8

Also if your building divider walls they also need to allow for slab movement, more on that here:
Divider wall construction.. see thread 133 and 135 here:
https://talk.classicparts.com/threads/lakeroadsters-high-country-barn.22110/page-7

Steel liner panels are great, but if your hanging cabinets on a wall, plywood or OSB in the areas where the cabinets go makes a lot more sense. The ribs on the metal sheathing don't work well with flat backs that are common on wall and floor cabinets.

____________________

It may even be reflective enough as-is, and let you avoid the metal on the roof.

Not sure how fireproof the plastic is...

 

[GRivera]

I have a similar building (32 X 48 X 10 with scissor trusses) and have a similar overall plan.
If you're going with rolled insulation in the ceiling, I'd look for the kind that comes wrapped in plastic. That would let you avoid the separate vapor barrier in the ceiling, and it would protect the insulation on all sides from condensation forming or dripping down onto it.
Something like this:

It may even be reflective enough as-is, and let you avoid the metal on the roof.

Looks great. What is the R rating on your insulation?

Does the bubble wrap between roof and trusses affect anything?

 

[stm317]

That's not mine, just a picture I pulled from the internet. It looks like most of the blankets are available up to R25 with some options for R30 as well. With some more diligent searching, you might be able to find a higher R value, or try layering additional insulation on top.

 

[GRivera]

Gotcha!

 

[cbrooks118]

I am in the planning stages of finishing the inside of my pole barn as well, and I had the idea of installing girts as Firebrick suggested. That was my initial thought and plan, but a carpenter friend came by and suggested that we install the OSB directly on the girts that were used to hang the metal, just measure to make sure our nails aren't in the same spot as the sheet metal screws. This would make my electrical plan and boxes be a super tight fit, but it would save some money. I am going to insulate, but it doesnt need to be very thick here in Texas. if it gets too cold or hot, I am not usually working in the barn anyways. I will be installing cabinent's and a few shelves, but not anything super heavy. Is this a bad idea that I should just ignore?

 

[GRivera]

Still haven't gotten this phase off the ground.

My roof scissor trusses are 4/12 outside 2/12 pitch inside. Can blown-in insulation be used for ceiling or will the slight slope have it gather in eaves?

 

[GRivera]

Anyone?