Insulting a barn roof

[Steve Rozmiarek]

It looks like there is a chance I could be moving my woodshop again. This time to a barn, which sounds really appealing to me. It's a standard layout, divided into three sections, with the center having a haymow. Good ceiling height, good roof, and not a terrible amount of structural issues. I'm developing a plan should this materialize to use the center section and haymow, and one of the sides for the shop. It would actually be a little smaller than my current shop, which I love, but this one would be in better location.

My question for you construction guys, how would you insulate the roof to best keep the ceiling height? Steel roof over osb over original board sheeting. I'm tempted to just consider fiberglass batts in the bays because I think the roof will breath to some extent over it because of the gaps in the original sheeting. Thoughts?

For the record, I'll add that I didn't insult the barn roof, that I know of. Leaving the title of the thread alone though because it's amusing.

[Kent A Bathurst]

Steve -

I am waiting anxiously to find out what you did to insult your barn roof?

Not only what and how, but why?

[Mel Fulks]

The last "insult" was to an attic ,and I was the policeman on that one. Now it's risen to rooves. Gentlemen, civility please!

[Steve Rozmiarek]

LMAO!!!! This is why you should never post a new thread from your cell phone and not proof read...

Maybe it was a freudian slip, maybe I was feeling like the barn would be insulted by the very thought of being repurposed as something besides the noble calling of domestic livestock domicile? Maybe the barn has feelings too? I only hope it's not a needy personality... Oh brother, this could get weird.

[Allan Speers]

I only wish I had an unused barn to insult.

[Allan Speers]

Once your barn gets over it, I suggest the exposed batting. - But use mineral wool, not fiberglass, as the wool doesn't put dangerous flecks into the air and doesn't make you itch when you touch it. (It costs a little less, too)

The reason I like the exposed bats is because then they will also act as sound absorption, which isn't a bad idea in a woodshop. If you have a lot of high-pitched machines, stick with 3 lbs / sq ft mineral wool. However, if most of the noise is mid & lower frequencies (like with a big DC) then opt for some denser wool. Maybe 5 lbs.

if you do use rigid fiberglass, make sure you cover it with some kind of cloth or burlap.

[Steve Rozmiarek]

And I feel so bad for doing such a thing Allan!

[John K Jordan]

My architect friends recommend spray-on foam insulation. Another friend who is a builder used it in his own buildings.

[Roger Pozzi]

My architect friends recommend spray-on foam insulation. Another friend who is a builder used it in his own buildings.

Plus 1 !!!! I had a warehouse sprayed quite a few years ago and it is fantastic! You don't need to provide air flow between the roofing and insulation and it's totally air/water tight. But,,,,also very expensive, at least in my area.

[Steve Rozmiarek]

Roger and John, I have a built in knee jerk type of response to sprayfoam. Probably because it's so ridiculously expensive in this area that I've given up on it. Also, I like the idea of being able to reverse whatever I do to buildings, so spray foam is down the list of options a bit.

The barn has 2x8 (full dimension) rafters on 24" centers, so something with more R per inch wouldn't be bad. Haven't checked yet, but I suspect that mineral wool beats fibreglass?

[Brian Tymchak]

...You're nothing but a saggy, mold-ridden, beetle-infested pile of half-rotten No. 2 shorts!!!

[Steve Rozmiarek]

...You're nothing but a saggy, mold-ridden, beetle-infested pile of half-rotten No. 2 shorts!!!

Now that ought to insult any building up to and including outhouses! Lol!

[Walter Mooney]

It looks like there is a chance I could be moving my woodshop again. This time to a barn, which sounds really appealing to me. It's a standard layout, divided into three sections, with the center having a haymow. Good ceiling height, good roof, and not a terrible amount of structural issues. I'm developing a plan should this materialize to use the center section and haymow, and one of the sides for the shop. It would actually be a little smaller than my current shop, which I love, but this one would be in better location.

My question for you construction guys, how would you insulate the roof to best keep the ceiling height? Steel roof over osb over original board sheeting. I'm tempted to just consider fiberglass batts in the bays because I think the roof will breath to some extent over it because of the gaps in the original sheeting. Thoughts?

For the record, I'll add that I didn't insult the barn roof, that I know of. Leaving the title of the thread alone though because it's amusing.

The title was the only reason I clicked on this thread. I couldn't wait to see some of the replies, because i know there are many quick-witted Creekers out there with a retort just waiting to be typed!

But seriously, with 24" o.c. rafters, whether you use either fiberglass or mineral wool, i would staple chicken wire (poultry netting) to the inderside of the rafters after you've installed the insulation, because batts that wide will tend to sag quickly. I would imagine that fiberglass batts are probably more common and more easily obtained than mineral wool, thus possibly cheaper. If you use the batts with either a paper or foil face on them, install with the paper or foil facing the heated/cooled space. If you're installing it yourself, get a pair of tube socks, slit the toe open and pull one onto each arm to act as a sleeve to keep the fiberglass off your skin. Dispose of the 'sleeves' when you're finished. Get a good N95 dust mask.

[Kent A Bathurst]

Now that ought to insult any building up to and including outhouses! Lol!

I am working up some "yo mama" slams for the next time I see a barn when I take a drive in the country.

One of them - still needs a bit of refining - is............ "Yo mama is an outhouse"

Also...

"Yo mama's make-up was applied by a flock of pigeons"

"Yo mama's so wore out she don't even cast a shadow"

Trying to think up a hook that connects a barn roof to a mobile home roof in a tornado......not quite connecting yet............

[James Conrad]

If you decide on a batt insulation, cover it with a vapor retarder. Otherwise, the moist warm air will travel through the insulation and condense on the other side. Without seeing the structure it's hard to be super specific. Batt insulation does not stop the passage of air alone. Cover it with rigid xps or other vapor retarder and tape the seams, it's less insulting for the building too.