Insulation in a Pole Building?

[Justin Thomas]

I'm trying to insulate my shop, it's a pole building. What is the best way to insulate this thing? I would like to use fiberglass bat insulation.

I know that the vapor barrier goes towards the finished side but was also wondering could I put it towards the exterior?

I think it would be easier to staple the insulation to the horizontal 2x4's that are attached to the exterior side of the 6x6's. What will it hurt by putting the vapor barrior out?

[Riversong]

Re: Insulation in a Pole Building?

What will it hurt by putting the vapor barrior out?

Only in the winter.

What kind of siding? What kind of interior wall surface? What kind of inside temperatures and humidity levels? Will the insulation cavity be completely air-tight (fiberglass is notorious for encouraging convection)? Will the space be air conditioned?

In a mixed heating/cooling climate it's best to leave out the vapor barrier as it will be on the wrong side (warm side) for half the year. If you must use fiberglass, use unfaced batts and make the thermal envelope as air-tight as you can.

[No faux zone]

Re: Insulation in a Pole Building?

What about using ridged foam panels and metal z-fir strips? Or skip the strips and glue them to the back side of the sheathing?

[ddolman]

Re: Insulation in a Pole Building?

As others have asked, what are the exterior and interior finishes going to be? As already mentioned, fiberglass only works if there is an effective air barrier on both sides of the insulation. It is common around here to use metal cladding here for exteriors of shops and barns. This type of exterior has a good life expenctancy in almost any weather, but it does not offer the building much in the way of an air barrier. If you are using fiberglass, you should consider using tyvek or some other wrb to prevent airflow from reducing the insulating value of the fiberglass.
In order to keep the insulation in the large cavities between poles, we have shot nails all through the exterior strapping before you apply the exterior siding and then you have a bunch of points to "hang" the fiberglass from.
Having said all this, when we build this type of building I highly recommend to the customer to use a blown in place cellulose insulation as it is dense and an effective air barrier.

[Justin Thomas]

Re: Insulation in a Pole Building?

The building is sheeted with 7/16 OSB and Tyvek house wrap. The interior, i was planning on hanging drywall. I don't think that I will put AC in but may down the road. I am going to put a electric heat unit from the ceiling and will be used just to keep things from freezing.

What type of R-value can you get from the foam insulation and would it be cost effective?
If i use unfaced insulation how will i keep from falling in the walls, remember there are no stud bays.....?

[ThingOfBeauty]

Re: Insulation in a Pole Building?

Did you already sheathe the building? Could you change over to foam board instead of OSB?
Spray-in-place foam is usually R-3.5ish for open cell and R6-ish for closed cell.
Cost effectiveness is a little more complicated than we could answer without a lot more information. Mainly what temperature would you keep it inside, and what other heat leaks are there such as air leaks, the ceiling, doors, other openings (windows etc.)
If you don't heat much, and/or if other parts of the building leak a lot of heat, it will be "less cost effective" to use better insulation in the walls.
By and large you can use normal faced insulation, with kraft or "smart plastic" facings, in the NOVA area without much trouble.

[No faux zone]

Re: Insulation in a Pole Building?

This article says 4 per inch on foam board.

http://www.espenergy.com/foam_board_insulation.htm

2 layers of 2" would get you a good R-16. I can't help on the prices in your area. I would price it up and then check it against spry foam. If it close, go with the spray. It will really tighten up the building from air leaks.

[Riversong]

Re: Insulation in a Pole Building?

The building is sheeted with 7/16 OSB and Tyvek house wrap. The interior, i was planning on hanging drywall. I don't think that I will put AC in but may down the road. I am going to put a electric heat unit from the ceiling and will be used just to keep things from freezing.

What type of R-value can you get from the foam insulation and would it be cost effective?

If you're not going to heat the building and would like not to cool it, then only minimal insulation will be cost-effective. It'll mostly help keep the space cooler in the summer.

If i use unfaced insulation how will i keep from falling in the walls, remember there are no stud bays.....?

And, if the building won't really be either heated or cooled, then it doesn't matter which way the VB faces - do whatever's easiest. But try to seal the insulation cavity, as much against critters as wind.

Below is a comparative cost for insulation (I believe it's relatively recent).

For an R-19 wall:

The installed costs for cotton batt insulation is about $1.20 per square foot.

Installed cost of sheep’s wool batt insulation is about $2.40 per square foot.

Fiberglass blown through a membrane costs about $1.40 per square foot,
(approximately double that of batts)

Cementitious foam costs about $1.45 to $2.45 per square foot for the same R-value.

On a small residential remodel with open stud cavities, the installed cost of cellulose can be as much as 50% more than fiberglass batts.

Cellulose wall-spray insulation costs about $1.20 per square foot.

Depending on the supplier and geographic regions, installed cost for in-cavity sprayed-on cellulose, fiberglass and mineral wool can be about 50% higher than a typical fiberglass batt installation.

The installed cost for sprayed foam insulation runs about $1.25 to $2.25 per square foot, depending on wall thickness and type of foam.

There are two types of spray foam: open-cell (isocyanurate) and closed cell (polyurethane). The closed cell foams typically have a higher R-value than open-cell foam. However, open-cell foams are typically more environmentally friendly with respect to blowing agents and off-gassing.

Insulated Concrete Form (ICF) material cost ranges from about $1.75 per square foot to about $3.50 per square foot in addition to installation labor, reinforcement, bracing, and concrete.

[jamcarp]

Re: Insulation in a Pole Building?

Another way I've used in the past is to rip 1-1/2 ridgid foam to fit between the sidewall girts and then hung fiberglass batts vertically, you can attach at the top and then, when you add interior girts -either 2x4s or hattrack or whatever you use to support the drywall they help hold insulation in the wall cavity. Just doing a quick search showed lots of sites with info, such as metalbuildinginsulation.com

[Baer Construction]

Re: Insulation in a Pole Building?

[QUOTE=Justin Thomas;436316]The building is sheeted with 7/16 OSB and Tyvek house wrap. The interior, i was planning on hanging drywall.QUOTE]

If you plan to hang drywall on the inside, and I'm assuming your poles are 4' or more on center, I would put in a sill plate and whatever studs it would take to get 2' on center. Does two things for you, plenty to staple kraft faced insulation to, and a good spacing for sheetrock to be hung from.

[ddolman]

Re: Insulation in a Pole Building?

If you plan to hang drywall on the inside, and I'm assuming your poles are 4' or more on center, I would put in a sill plate and whatever studs it would take to get 2' on center. Does two things for you, plenty to staple kraft faced insulation to, and a good spacing for sheetrock to be hung from.

If you are going to do that, then I would suggest replacing the external 2x4 strapping with rough 6" girts applied between the posts horizontally at 2' o.c. This allows you to eliminate the exterior strapping, seals the cavities from eachother much better as there is no gaps around the posts and from bay to bay, and provides a stonger wall than studs that are attached to a sill that spans the poles.

[dakota]

Re: Insulation in a Pole Building?

This is the down side of pole or post frame buildings. The others are correct a lot depends on how the interior side is finished and the interior of the building is used. My first choice is to use spray foam on the exterior skin. here we use about 3" on steel or post frame buildings. There are lots of other insulation systems for post frame building most are installed between the steel skin and girts before the steel skin is installed.

A less expensive method is to frame out the interior wall 16 or 24 on center depending on wall finish. you can even inset them to be flush with interior surface of the post's. Then blow in cellulose insulation. Yes even if you blow 6 or 8 or even 10 inches thick. You can blow this in so it packs and dose not settle. It will stop most air circulation. Unlike fiberglass bats, which need a closed cavity to work at all. You can also put up girts on the interior of the poles. Many times these can be 4' to 5' centers. Install a liner panel, usually a lighter gage (29) and only painted, no expensive fade resistent coatings as you need on the exterior. I have built several commercial buildings this way. Roof trusses 4' oc, steel right on the bottom of the truss. A good insulation contractor can blow the walls and ceiling of a 5,000 sf building in 8 to 10 hours.

[Frank-builder]

Re: Insulation in a Pole Building?

How far apart are the studs?
How thick are they?
By far cellulose is the best (ease and cost per efficiency)
The max a stud can be for sprayed cellulose is
2ft oc.
You really won't need a vapor barrier with cellulose
is you use tyvek.
What about the ceiling--loose cellulose

[backhoe]

Re: Insulation in a Pole Building?

I built a steel sided building. I used 2x4s flat to screw the siding to. On the inside, which left an inch and a half air space, I attached 5/8 inch Celotex sheeting and taped the seams. I did the same to under the roof. Without any heat, the temperature never goes below 30 degrees with the doors closed and no heat. I keep canned vegetables in refrigerators and none freeze. In the summer it never gets above 80 degrees. When I want to work there in the winter, I use a 30K btu propane heater that heats the building in 20 to 30 minutes. The building is 28 by 48 and ten feet sidewalls and I have an upstairs in it. 5/8 inch of styrofoam with aluminum foil on both sides does the trick.

[dakota]

Re: Insulation in a Pole Building?

How you build realy depends on where you live, and how the building is used, and the engeneering. If the interior is to be finished and you need a frost footing, it is easer to stick frame and use bats, then sheet rock.

As I mentioned above many times I have used 6x6 or 4x6 4'centers. If the roof height is only 10' you could use 4x4. With roof trusses 4' oc. exterior perlins are 30" oc with 28 gage steel screwed on. You can direct apply 29 gage liner direct to botom of trusses 4'oc with loose fill. I will direct apply liner horzontaly over posts on 4' centers.Blow in cellouse to fill the cavity. You do need a tight skin on the exterior to do this. This type of building is primarly used for whare house space, grages,shops, place where you keep it above freezing 40 or 50 degrees, and low humidity. I did a 60X 120 building this way 2 years ago and they say it is more comftorable then his home. But you need to rember there are 3 doors and almost no windows.

If interior finish is not a concern, I would use 1-1/2" foam between the perlins, or 1/2" thermax under the steel skin. Spray foam is more expensive but will do a better job. Buidings over 50' span I do try to use steel frame and spray foam. This is about where it becomes cost efective to swithc to steel.