Paralyzed by indecision on polebarn ceiling insulation

[bkanneg]

I had a 30 X 50 polebarn built and am trying to finish out a 20 x 30 portion of it as a "man-cave".

I am currently framing out the sides 16" OC and am planning on putting in a drop ceiling at about 9 feet.

I'm pretty new to home renovations, so I'm just learning as I go along.

I'm very confused on what to do with the roof of the polebarn. Do I put batt insulation on it? If so, how do I attach it to the roof? I had double bubble insulation installed while they were building the structure. It surrounds the whole thing. Is this actually insulation, or just a vapor barrier sort of thing?

Can I just attach some R-30 insulation to the Purlins on the roof? Will this do any good to the room below it? Do I need to worry about moisture with the double bubble on the roof? I'll try to add some pics so you can see what I'm working with. The tresses are 5 feet apart if that makes any difference. How much weight can the tresses take?

I appreciate any advice you can give this beginner!

 

[Bull]

Welcome aboard. We have plenty of folks on here who know their stuff when it comes to all aspects of building, insulation included. I am not one of those people.

I predict, however, that one bit of advice you are going to get is to make sure the insulation does not touch the underside of the metal roof for fear of condensation buildup and then rot. That roof has to breathe. What kind of vents are there on the building?

 

[bkanneg]

I don't think there was any vents installed when it was built. It does have the double bubble insulation around it that I assume acts as some sort of vapor barrier. Is that correct?

 

[bkanneg]

Don't know if this makes a difference, but the other side of my building that I won't be finishing is just going to have open rafters with the double bubble insulation.

 

[Bull]

I can't believe this thread isn't getting more attention. We have plenty of guys on here with the knowledge to help you.

Here is my suggestion: start a thread in the Garage Gallery section that shows your building. If you have pics of the build process and then the building now, that would be great. People love to look at builds. Then, after getting their attention, you could ask them about your insulation.

 

[cyamaha2007]

Lets call your man cave a office. I wouldnt do a drop ceiling. Frame out your office with 2x4 stud walls, Use 2x10s or particle board engineered joists to span the walls and they will be ceiling joists. You can attach drywall to them. Then you would insulate with batt or blown in insulation above the dry wall. This would be more expensive but the best option. What you suggested would not help heat or cool your office unless you left the ceiling open. Also attaching insulation to the botom of steel siding can be cruddy, You would generally insulate the bottom cord of the truss. If you left the ceiling open you would have a huge dead air space to heat and cool.

 

[cyamaha2007]

heres a pic of what im thinking http://www.panelbuilt.com/media/images/large/148.jpg

 

[bkanneg]

Thanks for the advice. Would it be a problem for the ceiling joists to be 20 feet long? Is that an acceptable span without compromising the integrity of the joist?

 

[cyamaha2007]

Yes they can be that long. Call the lumber yard they will have a span chart. If i were you id use a engineered joist They are lighter and generally cheaper. You can call a roof truss company they usually deal in roof trusses ceiling joists/ floor joists. This is a engineered joist.http://vermontpassive.com/sites/default/files/images/iLevel.jpg. I have been building units like you want at work as needed. I do them on the weekend as i am a machine fabricator( rough carpentry is not my title) They are real efficient to heat and cool. And compared to other options is the best cheapest fastest.

 

[bkanneg]

I called the local lumber yard and the I-joists were pretty expensive. Would 2x8s or 2x10s work on a 20 foot span? Remember, this is basically just for drywall with rolls of insulation above it.

Thanks again.

 

[cyamaha2007]

You could probably use a 2x8 if you ran a 1/4in cable up to a truss above in the center span of 2x8. This would cut the deflection of the 2x8 way down.

 

[shawn84&92]

I will be watching this thread. I have a 30x40 pole barn with a 20x40 enclosed shed that is going to be a living area. I have 2x8's that span 20 ft, that will be my ceiling. The joists are 2 1/2 feet apart, and I am thinking about putting in two 15 inch wide r-19 batts in between each joist. I also have the double bubble insulation.

 

[bkanneg]

Cyamaha2007 - do u think that drywall and insulation is heavy enough to make a 2x8 bow? What about a 2x10? Would that be better?

 

[cyamaha2007]

Its the static span thats the problem. I would just worry about the drywall seams cracking. Not that i think it will cave in and kill every one. Its a light load but with a 20ft span you have alot of leverage in play.

 

[djhoosier]

Would you consider a "tall rib" sheetmetal ceiling ? For our building, I used the tall rib for the ceiling (purchased from a regional supplier of building seconds) screwed to the bottom of the trusses and blown-in cellulose above (vapor barrier between truss and steel). The taller rib steel is designed to carry the load of the insulation. Works like a champ after 5 years...but have ridge vents and soffit vents to let the air in and out.

 

[bkanneg]

How does the sheetmetal compare to drywall on cost and ease of install? I'm doing most of this myself and don't have much construction background.

 

[jbs]

This span calculator is useful. Depending on where you are located and how much insulation you need, you could leave the option of adding some decking above the room later (for storage). This means the insulation would have to fit between the joists, and not lay over it, and the load-carrying capacity would need to be higher (2x10 or 2x12). Its hard to tell from the pics if there is enough space above to make this a useful option.

 

[djhoosier]

The hi-rib steel that I bought was from a builder supply who sold a little bit of everything...ie - good steel and factory seconds. I bought the seconds...had imperfections that the manufacturer wouldn't sell as perfect. Unless you really looked, couldn't tell there was anything wrong. Might be dimple or a ripple in the sheet. You can order the hi-rib from various suppliers. The steel is designed for these spans and the addt. weight of the insulation.

Me and the Mrs. put up enough to cover the top of our 36 x 48...just the two of us, along with the help of a roll-around scaffold and drywall lift. The sheets were 9' long if memory serves to cover the 8' truss spacing. Place the sheet on the lift, raise it up and I'd climb up the scaffold and screw it to the truss bottoms. As long as the first row was straight to the building, went up easy. No worse than drywall. Overlapped away from the doors so you couldn't see the overlaps...like vinyl siding.

I would do it again in a heartbeat. No wood cost for the framing between the trusses to hang the drywall, no mudding, no sanding and no painting ! Ended up being cheaper than drywall because no framing was needed behind the steel, as opposed to drywall.

 

[cyamaha2007]

If you dont have a ridge vent and or soffit vents sheeting the bottom of the trusses with anything can be bad.

 

[cyamaha2007]

You can buy number 2 metal for $50 a square or 10ftx10ft.

 

[Ron Lombardo]

... I would use insulated ceiling tiles in a dropped ceiling with 2x4 layins ...for a few reasons ... any framing weight added to the roof joists your going to need to check with the manufacture of the bldg trusses to see if they will take the added weight. Second to add insulation up at the roof level as mentioned is going to need a assembly of framing and insulation and going to be costly ...keep in mind those trusses look space pretty far apart.

I guess you could also build a structure with in a structure ..but also costly.

So I think your on the right track ..frame the exterior walls with 2x4's and use conventional batt insulation and a dropped grid ceiling system.

Ron

 

[911mike]

If you go drop ceiling use 24" wide rolls of insulation and put the seams over the center of the tiles NOT over the T- bars. Much better seal this way.

 

[Dave Maxwell]

I'm on 9 foot centers. Can I use that steel and not have any cross supports without it sagging. I assumed I would have to frame it out even using the steel

 

[smokem2020]

I used 16'6" steel on 8' span trusses for a 40'x100' pole barn. there was no sagging when supported on the middle truss at 8'. Stapled 6mil plastic first, installed medal, then went after it with 18" of blown in insulation. Should have blown in the walls to but went with dealer installed hanging double 4' wide 6" thick fiberglass, The walls were really drafty at the joints. Good luck with your choice.

 

[markw365]

My dad built a "room" inside his 35-40' building. One whole wall opens into the rest of the building on a slide. He heated/cooled that part of the shop while the rest of the shop was hot/cold depending on the weather. This is in rural Iowa. Cheaper to heat where the one car/job you're working on than the rest of the shop where you are storing stuff. The roof of the shop was storage for tons of VW sheetmetal.

 

[bkanneg]

Can you put rolled insulation on top of a drop in ceiling? Will the grid hold that much weight?

I just looked at my structure, and it looks like my ceiling joists would have to be 20 feet long. I can only use 2x8 because of the size of the tresses (I built the wall up to the bottom of a 2x8 on the sides that is on bottom of the tresses). According to the internet (has to be true, right? lol) a 2x8 can't handle spans that long. Would I have to go to a manufactured I-beam sort of thing? Will it handle a 20 foot span? How much additional is that?

The drop in ceiling looks like it would be pretty expensive. My room is about 20 X 30, so 600 square feet or so. I thought the drywall would be cheaper if I could get the ceiling joists installed.

This is way too complicated!!

Thanks again for all advice.

 

[bkanneg]

Sorry, but now I'm more confused. By looking at this chart:

http://www.tomsangle.com/Websites/rightangle/images/Articles/span_table_1.pdf

It looks like a 2x8 can be used on a 20 foot span. So, which chart should I use?

Again, this ceiling will only be used for rolled insulation and sheetrock.

 

[mrobins297aaa]

I would go for the lay-in ceiling with rolled insulation on top. The grid is plenty strong enough to hold the tiles and insulation as long as you support the grid from above.
I wouldn't be using a 2x8 to span 20'....thats crazy.

I would use the 2x8's to span between the trusses above and then hang your ceiling from them with wire. you should check but I would think that those trusses would be plenty capable of supporting a lay-in ceiling grid with insulation........not much weight there...........now if you use drywall then thats something else.
lay-in ceilings with insulation on top with the grid hung with wire is done all the time in commericial construction.

 

[shawn84&92]

My pole barn has 2x8's on a 20ft span for the enclosed shed, which will be my living area. They are on 30 inch centers. I am also contemplating the ceiling. Thinking of metal and putting two 15 inch wide insulation batts in each section.

You can see pics in my build thread.

http://www.garagejournal.com/forum/showthread.php?t=142674

 

[bkanneg]

Shawn84&92. Any way you can give a pic of your 20 ft. span 2x8s? I couldn't quite see them from your pics in the other thread. I'm interested to see how you did it (I may copy it). Any issues with the ceiling drywall sagging, or have you not progressed that far yet?

Thanks

 

[shawn84&92]

I am not that far yet, still bare 2x8's. What part do you need a close up of?
Shawn