Insulate/Upgrade Existing Pole Barn/Shop

[yooperdave]

Be careful about adding load to the bottom chords of trusses.

Truss manufacturers go to great length to make the trusses as cheap as humanly possible.

There is not typically available structural margin - the bottom chords are normally only designed for axial loads (usually tension). Adding load to the bottom chord introduces a new bending component which usually requires larger structural members.

If you have the shop drawings which the trusses were manufactured from, the stress interaction ratios can be reviewed to see what structural margins you have available.

Good Luck.

Yooper Dave

 

[srs]

Thanks for asking this as it might have been misleading. Here, code is R30 for a ceiling in a residential home. R30 is reached at ten inches. R3 per inch is about how it's figured. Going two extra inches exceeds code and allows for some settling over time.

Adding more then 12 inches has a few drawbacks with minimal reward. Every inch costs money. There is a point where you don't get anything back with more. Kind of like how heavy of a jacket you need to stay warm. There is a point were you don't need to put on any more layers. You can gain a higher R factor with thicker insulation, but you start getting into that area of it not making a difference, or it's not something that you can tell in energy savings.



Eddie

Eddie, thanks for your explanation.

 

[Mike Costello]

Here's some pics of bubble wrap installed on my 30X60 shop/garage. Shiny side is out with white side in. Obviously, easy to install when building new, but can be done on existing pole barns....just more time needed to install.
I had it installed on the walls and roof. The walls are 12' high and a vented ridge cap runs the entire lengh of the building. The guys used a nailer firing button staples to attach the wrap to the purlins.
Some benefits:
1) Cost was reasonable for that size of building.
2) The reflective white side made for good lighting.
3) No invasive drafts.
4) And the best part....Temperature control works great.
Inside temps are about 10-15 degrees warmer than outside
at any given time before heat. I use a portable kerosene
heater rated at 125,000 btu to get to comfortable in the
shop, usually about 55-60 degrees. Takes about 20 min.


Last week the temps in Missouri dropped to about 1 degree. The thermometer showed 19 degrees in the building. Fired up the heater and was comfortable in about 20 minutes. So far, I've been impressed! We'll see what happens in warm weather.

 

[survriggs]

YooperDave:
Thanks for the comment; I really hadn't thought about the bottom chord of the truss being mainly for tension and not to support a vertical load. Unfortunately I don't have any engineering drawings for the trusses.

Fortunately I will not be nailing a ceiling to the trusses. I purchased enough 1-1/2" x 4' x 21' Dow blue-board foam insulation to do the entire shop. It was used but at $0.25/sq. ft. it was quite a bit cheaper than new. I plan to follow Eddies advice and nail it to the roof purlins.

To help brighten up the shop a bit I plan to cover up the dull blue color in the roof insulation with some kind of white paint that will stick to the insulation.

When decent weather and the weekend coincide I'll get started and post some pics.

Mike Costello:
That's a nice looking building you have there. (so clean!) If I build another one it will be insulated something like that. And yes, it was cold in MO last week, 4 in West Plains. One thing abut Missouri weather; if you don't like the weather, just wait a few days and it'll be totally different.

Ralph

 

[Mike Costello]

Don't let the cleanliness fool you...that pic was taken just after I sealed the concrete and the building was still empty! Now, its starting to look like a garage/workshop.
And...Missouri weather, you're right, it can change fast. I've seen the temps drop as much as 30 degrees in an afternoon! Mike.

 

[john_bud]

Ralph,

I did the exact thing you are doing, but about 18 years ago. The biggest problem was that the spacing between the posts was only "aproximately" 8'. The widest was close to 9' and not a one were square. For an amateur carpenter, that tossed in a large monkey wrench. I did NOT do a very great job of it either!

jb

 

[survriggs]

Well, 8 months after the last post in this thread I finally got the insulation installed. On the walls I put the insulation against the purlins and placed OSB over that. Nailed the insulation against the purlins in the attic. Would like to paint over the blue insulation if I can find a paint that will stick. Re-wired and placed an outlet 4.5 feet high every 8 feet on the perimeter. (can't have enough outlets). Even had enough to insert in the metal overhead door. Installed a window in the front also. Now comes lighting, cabinets, workbench, etc.

 

[EddieWalker]

Thanks for the update, you are way ahead of me. I'm still in the wanting to do it stage!!!

How would you rate the difference in there compared to before you insulated it?

What thickness of foam did you use?

Eddie

 

[survriggs]

Eddie:
there is a noticeable difference in the summer temperature inside.
Even with everything closed up it is much cooler. I also resealed and painted the tin roof with the silver paint. That probably helps too. The insulation is 1.5" thick.

 

[BungeeII]

Great job. I think about that deal you fell into every now and again. (Usually when I go in the pole barn and the walls are too hot to touch.)