Insulate/Upgrade Existing Pole Barn/Shop

[survriggs]

Hello all! I'm considering a project on an existing pole barn and thought I would ask some advice from TBN'ers. It's a typical pole barn, metal siding and roof, 24x36x8 tall with trusses on 8 ft. centers & concrete floor. I'm wanting to insulate walls and ceilings. The trusses have held up for 22 years but with the added weight of ceiling and insulation I plan to build extra rafters in place so they will be on 4 ft. centers. I will then add 2x4 purlins (if that's the correct term) between the ceiling joists to nail 4x8 osb to. I would like to blow wood cellulose in ceiling but am not sure if the weight of the ceiling and wood cellulose will be too much. I then plan to add studding on 24" centers and use fiberglass insul. and vapor barrier on inside and then use osb for walls.
Question #1: Am I addressing the structural ceiling issue correctly?
Quesiton #2: Any better ideas for insulating walls?
I'm sure I will get some different ideas and I welcome any and all. I've included some pics. I really enjoy the progress pictures that I see on TBN and when I finally decide which way to go I will keep progress pics uploaded if anyone would be interested. This is a great site and I've really learned a lot.
Ralph

 

[Conservation]

I think you would be very happy with that method. I am doing exactly what you describe to my new 40X40X15. I just ran 2' centers across the span between trusses that are 8' apart.
One thing I think you should plan for is venting the attic though. At very least, a ridge vent and some spot vents to get moist air out and vent hot air in summer.

 

[survriggs]

Conservation: If I can be assured that the 8 ft. span will support ceiling + insulation I will do exactly what you suggested....be a lot less work. What kind of ceiling material and insulation are you using? Also, since I am replacing the light panels in the roof anyways, I can ventilate it somehow at that time.

 

[MarkV]

Ralph it looks to me like the bottom cord of your roof trusses are 2x8, is that the case? If so I think you will be fine with the added weight. I would run 2x4 purlins vertically like was done for the roof panels.

MarkV

 

[EddieWalker]

... 24x36x8 tall with trusses on 8 ft. centers & concrete floor. I'm wanting to insulate walls and ceilings. The trusses have held up for 22 years but with the added weight of ceiling and insulation I plan to build extra rafters in place so they will be on 4 ft. centers. I will then add 2x4 purlins (if that's the correct term) between the ceiling joists to nail 4x8 osb to. I would like to blow wood cellulose in ceiling but am not sure if the weight of the ceiling and wood cellulose will be too much. I then plan to add studding on 24" centers and use fiberglass insul. and vapor barrier on inside and then use osb for walls. ...

Ralph,

Can you post some pictures of the actual truss?

By building another truss in between the existing one, and then adding purlins to the trusses, you are probably going to be fine. It sounds like allot of wood and money to go this route.

The 8ft spacing of your trusses makes it hard to span the distance between them to add OSB, so I'm wondering if you've considered using metal R Panels?

Your building is 24 feet long, so you could buy the panels in 12ft 6in lengths and screw them into your bottom chords. Overlap the panels and screw them together will make them plenty strong. If the trusses are engineered, they will be able to handle the weight. If they are not, it's anybodies guess.

You could add the insulation from the top when you replace the skylight panels, or you can do it as you go. I prefer blown in insulation since it's cheaper and you get total coverage. Home Depot and Lowes both let you use the machine for free if you by ten bags of insulation.

Depending on your ridge cap, you might find it easier to vent the attic space by cutting and installing gable vents on both sides of your peaks. This will give you good cross flow of air through your attic. Wind turbines are OK, but not my favorite. A good peak vent for metal roofs are usually pricey.

This is exactly what I plan to do in my shop. The only difference is my trusses are on 4 ft centers, but they are not as big as yours. The cold is killing me, not to mention the short days. Being able to work out in the shop when it's freezing outside would sure be nice.

Eddie

 

[survriggs]

Eddie:
I have attached a pic of the truss. They are engineered 2 x 6 trusses. I like your idea of putting purlins between and adding metal for a ceiling. It would make it a lot brighter. I'm still a little hesitant to rely on the 8 ft. span between trusses; I would rather be safe than sorry...it may just take me a little longer to build up the piggy bank. (it's been uninsulated for 20 yrs. - another few months won't hurt) I think I'm going to also look into pricing it for the walls also. How had you planned to cover and insulate your walls?
thanks for the advice,
Ralph

 

[Conservation]

I haven't decided on thickness, but OSB for the ceiling.
The metal is a great way to go also. The problem is the cost. It was three times as much when I checked, and even when I added the extra cost of the wood 2 by's, it was still twice as much. Metal makes for a much nicer interior, and they have interior grades that aren't quite as expensive as exterior.

 

[EddieWalker]

Looks like you have some very strong, well built trusses. No worries there.

I'm just guessing here, so it might not work, but I don't think you need any purlins with a metal roof. It only has to be strong enough to span 8 feet and the insulation. The ridges on the panels should be able to span the distance, and with screws, you shouldn't have any problem supporting the weight of the insulation.

The walls in my shop are covered with OSB. I don't have any insulation in the walls. I'll never cool the space, I just want to be able to heat it a dozen times or so in the winter when I want to do something out there, but it's too cold. Doing the ceiling should be a simple, fairly inexpensive way to accomplish this. My biggest delay is trying to decide what to use for the heater.

I also noticed light at your peak. Do you already have a ridge vent? If so, then your set for venting!!!!

Eddie

 

[BungeeII]

I haven't priced it out for myself lately, but...
For the walls, you might price out foam panels to nail to the existing purlins, followed with osb.

Sounds like you guys have the ceiling covered.

 

[survriggs]

I also noticed light at your peak. Do you already have a ridge vent? If so, then your set for venting!!!!

Eddie

The only venting is the spaces created where the topcap and the metal meet. I've attached a drawing of two options that I'm looking at for the walls. Any opinions welcome.

 

[2manyrocks]

Although you lose a minor bit on interior space by attaching interior purlins /rails to the posts, this is probably the fastest method. OSB or metal would be good for the interior walls. If the only purpose of OSB on the ceiling is to hold the insulation in place, I start thinking about running furring strips and 1/4 plywood instead of adding trusses.

Anyone care to venture a guess about material costs? Are they going to come down (like most 401k plan balances) or stay up?

 

[EddieWalker]

I haven't priced it out for myself lately, but...
For the walls, you might price out foam panels to nail to the existing purlins, followed with osb.

I think this is the most cost effective way to go. You already have the purlins in place, so there is no need to buy any more lumber for your walls. 3/4 inch foam is $12 a 4x8 sheet at Lowes or Home Depot. 2inch is quite a bit more, but with allot better R factor. Nail the foam up and then covering with OSB will give you everything you want in one quick and easy step.

As for your vent in the peak, this might cause some problems as it is. From what I understand, you have just a cap over your peak and the ridges of the roof are creating the vent space. This is fine for an open roof as it allows air movement out of the building, and if any water comes through during a storm, there's no damage because it goes straight to the floor.

Installing a ceiling will change this. Water that comes in from a storm will destroy the insulation and eventually rot out your trusses. You can either seal off those gaps with rubber foam designed for this, install a ridge cap that does not have the air gaps, or come up with something on your own.

Then either install a new peak vent that is water tight, or gable vents at both ends. Venting is very important and needs to be done before you get too far into putting in the ceiling.

As for the ceiling, I wonder if you could just put the foam panels up onto the purlins already in place? I hadn't thought of it in my own shop, but after reading Bungee's suggestion and agreeing with him on using it for your walls, why couldn't you do the same with the ceiling? I'd probably use screws with fender washers, but otherwise, you wouldn't need any OSB or anything else. You would still have your ceiling height and the ease of running anything across your rafters in the future if you needed to. If you put in a ceiling and insulated it with blown insulation, or even rolled fiberglass, it would be very awkward and difficult to add wiring across the shop if you decided you needed it in the future. With foam panels, you could do this easily any time you wanted.

The more I think about it, the more I like that idea. I'm gonna do some checking on this, as it has allot of merit.

Thanks,
Eddie

 

[survriggs]

Whoa! that's an idea for the ceiling. I just call my local lumberyard and 2" x 4' x 8' styrofoam is $32/sheet that equates to $864 for the walls and $864 for the ceiling. Kinda pricy!

1" is $14.79/sheet that would take it to $800 for both walls and ceiling. That would certainly take care of my weight concerns for the ceiling! Only problem I see leaving the styrofoam exposed is accidently poking a hole in it....and also the cost of 2"...

I'm going to have to do some figuring on my other options but this may be the most cost effective and quickest.

I'm on my way to the lumberyard and will post comparisons later.

 

[BungeeII]

I think you should stick with metal for the ceiling and cellulose for the insulation there. It's the walls you may want to simplify with foam & osb.
(Or, that's at least what I have pseudo-planned for my own older pole barn. Plus, I've had 2" exposed foam insulation on a new pole barn. That barn had an osb ceiling and cellulose.)

 

[MarkV]

I believe Eddie is saying to run styrofoam below the roof metal and attached to the purlins supporting it leaving a vaulted ceiling. If not, I would not run 8' spans of styrofoam between the bottom cords of the trusses unsupported.

MarkV

 

[survriggs]

OK, here's the scoop:
Insulation - 6" openface for ceiling 864 sq. ft......................................$370
Insulation - 3-1/2" w/vaporbarrier for walls, 864 sq. ft...........................$263
OSB 7/16 for ceilings and walls $6.60/sheet.........................................$356
Studs for purlins and walls 24" centers & plates....................................$140
Labor............................................................................................Free
Total .......................$1129
I have a contractor friend that does several hundreds of thousands of dollars a year with this lumberyard that will purchase for me and should save me some off of this price.

I have the end vents and enough metal to replace the skylights, so adding the "Oh No! I forgot to figure that" allowance, if I can get by less than $1500 I'll be happy.

I plan to heat it with a Schrader airtight wood stove that I have.

 

[survriggs]

As for the ceiling, I wonder if you could just put the foam panels up onto the purlins already in place? I hadn't thought of it in my own shop, but after reading Bungee's suggestion and agreeing with him on using it for your walls, why couldn't you do the same with the ceiling? I'd probably use screws with fender washers, but otherwise, you wouldn't need any OSB or anything else. You would still have your ceiling height and the ease of running anything across your rafters in the future if you needed to. If you put in a ceiling and insulated it with blown insulation, or even rolled fiberglass, it would be very awkward and difficult to add wiring across the shop if you decided you needed it in the future. With foam panels, you could do this easily any time you wanted.

Eddie: Sorry, I didn't read this post very well, MarkV brought it out - it's a great idea - now I'm back to the drawing board.
Ralph

 

[MarkV]

Ralph if you decide to go with the flat ceiling you should price the option of blowing cellulose insulation into the ceiling cavity. You can often gain a greater R value at a better price. It will be readily available at most lumber yards and they normally have the blowing machine available to rent at a reasonable rate.

MarkV

 

[dodge man]

I have seen metal buildings insulated with a material desinged for them. Kind of has a heavy vinly coating on the side that shows. I don't know how much this stuff costs or how easy it is to work with. It wouldn't be as finished looking as the OSB or similar material. By the way, I'm a land surveyor in Illinois.

 

[Conservation]

The foam would work great if you don't need a high R value.
I missed the part about the ridge vent. Is it a purpose meant ridge cap? They use those on homes also. It is very important to vent the attic to get mosture out. If you let the air up there get hot and moist, it will ruin insulation and eventually the wood. If you need high r value, osb and blow in has been the highest bang for the buck from what I have found. Steel is nicer, but more expensive.