Will this work? Moisture Barrier, Insulation & Drywall install question

[Wangstang]

I'm considering adding wall insulation and drywall in my farm building this fall and I'm trying to evaluate my options. There's bubble insulation directly under the metal for the roof. There are a number of reasons I have for wanting to avoid spray in foam, ranging from ease of adding wiring and such after the fact to costs. I'd prefer a bit more of a residential insulation and drywall setup. The job would include doing the ceilings as well.

I don't plan to tackle this until the fall but I'm doing some pre planning now.

Here's a crappy photo of the east side of the farm building, note the overhangs with vented soffits. There's also a ridge vent at the peak of the roof:

Here's a shot of the interior side of the walls:

So my plan would be to install a Tyvek type product on the inside of the walls first, so that it's nailed directly to the purlins and wrapping around the inside faces of the 6x6 posts. The next step would be to build stud framing into the wall spaces, then install insulation in the new studs before screwing drywall into place. A cross section would look like this:

I'll paint the dry wall but not mud it so that I can remove the drywall panels easily if I ever want to modify wiring or framing a later date. I may leave the most inward face of the 6x6 posts exposed to the inside, having the drywall essentially flush with those faces.

Obviously, the more ideal thing would have been to wrap the structure with a moisture barrier before the metal went up, but it didn't happen and I don't want to pull all of the metal siding to do it now.

For what it's worth, we had a pretty cold winter and a very wet spring/summer with lots of heat and I have not observed any issues with condensation or the "interior rain" issues some people have described on this board in the past.

Let me know what you think.

Thanks in advance for the advice!

Wes

 

[bullnerd]

8ft wide rolls of 6 in fiberglass hanging between posts.
Horizontal purlins (just like the outside)No interior framing wasting space.
Plastic vapor barrior.
Intior finish walls.

Plastic vapor barrior on underside of ceiling joists.
Interior finish on ceiling.
Blow in insulation.

Thats what I would do,and I would just use the metal like the outside,but white.Goes up quick and no mess like dry wall.


Nice looking building.

 

[Wangstang]

8ft wide rolls of 6 in fiberglass hanging between posts.
Horizontal purlins (just like the outside)No interior framing wasting space.
Plastic vapor barrior.
Intior finish walls.

I assume you'd put the plastic vapor barrier where I have it in the diagram and not between the insulation and the drywall?

On the 8'x6" insulation rolls, I've got several openings that are a lot wider than 8'. Just how wide can you get?

The door overhead in the exterior image is a 12x12 and the door in the back ground of the interior is a 18x10. I had two extra openings framed for 12x12 doors but closed off just incase I ever want to add them:

Thanks
Wes

 

[Sureshot]

The vapour barrier goes to the warm side of the insulation.

 

[Kevin C]

The vapor barrier goes to the warm side of the insulation.

No expert on metal buildings... But you have metal on the outside and no air space, you cant dry to the outside. If you put a barrier on the inside you cant dry that way either. That would trap any moisture that leaks inside the wall.

Seems like you need a vapor retarder on one side or ventilation between the metal and the outside of the insulation.

 

[Sureshot]

http://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers

 

[Kevin C]

http://www.greenbuildingadvisor.com/blogs/dept/musings/vapor-retarders-and-vapor-barriers

Good read....

 

[Wangstang]

http://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers

Thanks for the link.

I invited the Author of the above reference to join in on the discussion. I did not find any examples that cover the metal siding & roof situation that many pole barn owners have and I'm curious to see if he has any tailored advice for this type of construction.

Wes

 

[Delly]

I have a 28x34 pole barn metal style garage and picked up a 100 foot roll of plastic from Loews and stapled inside on the wood frame and around the 6x6 pollens etc.. Then framed it like you said and added vapor barrier insulation from Loews also it has the plastic wrap on both sides of the insulation then i picked up another roll of the plastic and stapeled that also over the insulation , so its metal,plastic,insulation,plastic,then wood..no sheetrock on walls I used osb plywood 10 dollars a sheet at Loews the stuff they use on sheeting for new built homes, I then caulked all seems then painted it white looks good.. Now for the ceiling I sheet rocked that and then went up top and put down attic insulation the big thick stuff, the roof had the double bubble under the metal so I'm not worried about condestation dripping etc.. It's very warm in there in the winter and cool in the summer! Good luck

 

[Freefall_Doug]

Normally only want a vapor barrier on one side of the insulation only.

If the insulation got wet would it be able to dry in between two sheets of plastic?

 

[Highbeam]

Thanks for the link.

I invited the Author of the above reference to join in on the discussion. I did not find any examples that cover the metal siding & roof situation that many pole barn owners have and I'm curious to see if he has any tailored advice for this type of construction.

Wes

I agree, the article is not applicable enough to metal siding applications as in a pole barn. While the metal is not airtight, it is not as porous as lap siding.

 

[bullnerd]

I bought my rolls right from Morton. But my posts arent as wide as yours. Sorry about that, I didnt notice. I paid just under 600 for enough to do my 30x40x10 Pioneer.

Watch the vid here, it shows a little of how morton does it.

http://mortonbuildings.com/why-morton/products/features/energy-performer/

 

[Angelfire]

Not sure how to handle the metal portion of the question but if you plan to use house wrap under the metal, keep in mind, house wrap (ie. Tyvek) is not a vapor barrier. It is a moisture and air barrier. So yeah, it would probably be ok to put there. I wouldn't put plastic there. Then get the appropriate vapor retarder for your climate for under the drywall (keep in mind that paint on the drywall actually counts for some of that retarder).

 

[Delly]

I have almost 8 inches between the inside wall and outside metal walls plus I have ridge and 12inch hangover vents, plenty of breathing there. Trust me it works.

 

[DuPontTyvek]

Great looking building, Wangstang. Catherine from DuPont here. Tyvek® can be used directly over studs where there is no sheathing, and in this configuration will perform effectively as an air barrier and water-resistive barrier. In the configuration that you describe, the Tyvek® will help stop air movement through the walls to provide a more energy efficient structure but will not be able to prevent the purlins and posts from damage as a result of water entering the wall. As you mentioned, a more ideal installation would have been to install the Tyvek® before the metal cladding. The good news is that Tyvek® is highly permeable, so water will not become trapped in the wall assembly assuming there is no vapor barrier between the Tyvek® and interior.

You can check out our full line of DuPont™ Tyvek® products to choose one that’s right for you here: http://www2.dupont.com/Tyvek_Weatherization/en_US/products/index.html.

 

[ROBINSHERWOOD]

All your ideas are good, but more cosmetic than practical, you really need a sandwich of 2 x layers of Tyvek, with, if you can find it somewHere, a thin layer of "Fibreglass Caravan mat in between". A 50mm / 2 inch layer of fibreglass will suffice. Afterwards you can board the inner wall to make it look good as in "Nice looking walls R-US", but what the insulation value or real benefit to you will be is highly problematical. Can I explain the problem this way:

You are not insulating this building to keep the heat in, BUT to keep the COLD, or intense cold out, and in my view insulating steel sheeted metal buildings is more of an false dream than people realise. Heating any building is expensive and a rich man will go broke heating that building of yours. Its an HEAT VACUUM PUMP you have built there, and I'd be ashamed to take your hard earned money for the job of insulating it. This work should have been done as it was being erected. And the air gap you are creating-will retain cold air, not warm air. And the top and bottom seals (roof and floor) will not live upto your hopes.

So the next question is: How much are you planning on spending on heating, and what on earth for. You have a lovely summer building there, and a death trap - meat fridge in the winter. No one ever wins fighting General Winter, If they did there would be no market for hot water bottles in bed, or trips to Florida in January.

R SHERWOOD, ENGLAND.

 

[Wangstang]

All your ideas are good, but more cosmetic than practical, you really need a sandwich of 2 x layers of Tyvek, with, if you can find it somewHere, a thin layer of "Fibreglass Caravan mat in between". A 50mm / 2 inch layer of fibreglass will suffice. Afterwards you can board the inner wall to make it look good as in "Nice looking walls R-US", but what the insulation value or real benefit to you will be is highly problematical. Can I explain the problem this way:

You are not insulating this building to keep the heat in, BUT to keep the COLD, or intense cold out, and in my view insulating steel sheeted metal buildings is more of an false dream than people realise. Heating any building is expensive and a rich man will go broke heating that building of yours. Its an HEAT VACUUM PUMP you have built there, and I'd be ashamed to take your hard earned money for the job of insulating it. This work should have been done as it was being erected. And the air gap you are creating-will retain cold air, not warm air. And the top and bottom seals (roof and floor) will not live upto your hopes.

So the next question is: How much are you planning on spending on heating, and what on earth for. You have a lovely summer building there, and a death trap - meat fridge in the winter. No one ever wins fighting General Winter, If they did there would be no market for hot water bottles in bed, or trips to Florida in January.

R SHERWOOD, ENGLAND.

This has to be the oddest first post I've read in a long time and you pulled up a thread that hasn't been active for months. For what it's worth it's 70+ outside right now...in the middle of December. If I was in Buffalo NY your statement may have some truth to it but your.a bit out of touch with my climate in NC.

Wes

 

[toyotadriver]

All your ideas are good, but more cosmetic than practical, you really need a sandwich of 2 x layers of Tyvek, with, if you can find it somewHere, a thin layer of "Fibreglass Caravan mat in between". A 50mm / 2 inch layer of fibreglass will suffice. Afterwards you can board the inner wall to make it look good as in "Nice looking walls R-US", but what the insulation value or real benefit to you will be is highly problematical. Can I explain the problem this way:

You are not insulating this building to keep the heat in, BUT to keep the COLD, or intense cold out, and in my view insulating steel sheeted metal buildings is more of an false dream than people realise. Heating any building is expensive and a rich man will go broke heating that building of yours. Its an HEAT VACUUM PUMP you have built there, and I'd be ashamed to take your hard earned money for the job of insulating it. This work should have been done as it was being erected. And the air gap you are creating-will retain cold air, not warm air. And the top and bottom seals (roof and floor) will not live upto your hopes.

So the next question is: How much are you planning on spending on heating, and what on earth for. You have a lovely summer building there, and a death trap - meat fridge in the winter. No one ever wins fighting General Winter, If they did there would be no market for hot water bottles in bed, or trips to Florida in January.

R SHERWOOD, ENGLAND.

Lots of problems with your post but I'll tackle one of them. Heat moves to cold. Always.

Insulation keeps heat in the building in the winter when it's cold outside and keeps heat out in the summer when it's hot outside.

 

[theoldwizard1]

The vapour barrier goes to the warm side of the insulation.

OP stated he would be using "house wrap", typically DOW Tyvek.

DuPont™ Tyvek® HomeWrap® is the original house wrap, incorporating unique material science that helps keep air and water out, while letting water vapor escape.

As a result, it can contribute to improved building durability by helping to protect homes against damaging wind and rain that can penetrate the exterior cladding.

 

[theoldwizard1]

Read this thread !

Cellulose Installing in Pole building...

Cellulose insulation is very effective and very cost efficient !

Because you have your purlins installed in the traditional manner, simply fill a whole cavity would probably cause the Insulweb to blow out at the bottom. Here is a suggestion. Install your drywall from the bottom up !

Put one row of drywall all the way around. Fill the cavities with cellulose and then install the next row.