Pole Building Questions?

[bkdawg61]

Hey guys I'm looking at getting a 30x40x12 pole barn built and looking for some input. Here is a little description of the building design....

30x40x12, 4/12 roof pitch with 2/12 scissor trusses, 20'x10' overhead door on 30' gable end and smaller entry door on right side by front corner. Double bubble insulation under the roof panels, eventually I would like to insulated the walls and put in a hot air furnace.

Question #1 Are vented overhangs on the eaves with continuous ridge vent beneficial and worth the added cost?

Question #2 Anyone have a garage door mullion splitting say 2-10x10 doors( I would like to have the 20' opening but don't want to open a 20' door everytime)

Trying to get a feel on things guys have cut from their builds to trim the cost and regret they didn't do.

Any input would be great thanks.

 

[matt_i]

Is a 2:12 roof even allowed? I don't think you can expect shingles to work at less than 3:12.

You will do better with higher pitched roof and an exterior that matches your house if that applies yet.

I would spend the money on perma columns. If you want to cut, take out windows.

Also you should look into planning the insulation right now. A friend had a pole barn built and then basically built a stick frame inside of that to insulate and hang drywall... a lot of double work.

 

[KDXSR5]

Is a 2:12 roof even allowed? I don't think you can expect shingles to work at less than 3:12.

You will do better with higher pitched roof and an exterior that matches your house if that applies yet.

I would spend the money on perma columns. If you want to cut, take out windows.

Also you should look into planning the insulation right now. A friend had a pole barn built and then basically built a stick frame inside of that to insulate and hang drywall... a lot of double work.

Read again. 4/12 roof, 2/12 scissor.

 

[bkdawg61]

The roof will be a 4/12 pitch the bottom of the scissor trusses would be 2/12. Unfortunately I am under a height restriction from the township so I am stuck with the pitch at 4/12 unless I change the sidewall height.

 

[matt_i]

Sorry I didn't read correctly earlier, glossed right over the first set of numbers

Relative to #1 I think it is valuable if you decide to insulate and have heat. The "cold roof/warm room" is best to prevent condensation and melting, icicles, and ice dams. In my opinion you want a low roof (obviously enough height to do what you accomplish) that keeps heat down where you feel it rather than concentrated up at the peak.

To that end, in planning, you will want to look at the truss spacing and make sure you have a plan in place to hang (drywall, metal, etc) on the bottom chord of the trusses, as the trusses need to bear that load and you may have to install more framing to give a place to attach the panel edges for support.

 

[dmcintosh]

I am in the process of building my pole building garage now. Had the contractor put up the building and pour the floor, and am working on everything else myself to save as much as I can. For insulation I decided to go with 2x6 'walls' in between the posts so it would be easy to insulate and hang drywall. Windows did add a bit to the overall cost, and can be added fairly easy after the fact if you are really right on budget. I'd say the only regret I have is not asking to have house wrap put on under the exterior metal. Thinking this would have helped with sealing things up for when I get around to insulating my walls. Otherwise, very happy with my choice of a pole building and choices I've made so far.

Good luck with it.

 

[DougWil]

Double bubble insulation under the roof panels, eventually I would like to insulated the walls and put in a hot air furnace.

Question #1 Are vented overhangs on the eaves with continuous ridge vent beneficial and worth the added cost?

A vented attic of eave and ridge vents requires a ceiling with the insulation above the ceiling not at the roof.

If I understand you, air would flow from the eave below the insulation and right out the ridge vent. And with it all that heat you are paying for.

 

[dmcintosh]

My understanding with pole buildings is that if you do not include the bubble 'insulation' you will very likely get condensation on the underside of the metal. Than, any actual insulation you put t the ceiling gets wet.

 

[astroracer]

Are you leaving the ceiling open? Insulating the lower cord? Insulating and drywalling the lower cord will work with the soffet/ridge ventilation scheme.
Definetly do the Tyvek/housewrap under the siding. Made a HUGE difference in my shop.
Stud in the walls, 24" OC. 2 x 4's work and they are cheaper. Look into spray foam when the time comes. If you build your 2 x 4 walls flush to the inside of the posts, you can spray foam the gap behind them and use batt inbetween. Lots of R there.
Mark

 

[bkdawg61]

Down the road I plan to insulate the ceiling and putting up the metal panels rather than sheetrock. I was told the same thing about the condensation problem and not insulating the roof. With using scissor trusses I'm thinking there won"t be much of an attic space to vent but i could be wrong.

 

[astroracer]

Down the road I plan to insulate the ceiling and putting up the metal panels rather than sheetrock. I was told the same thing about the condensation problem and not insulating the roof. With using scissor trusses I'm thinking there won"t be much of an attic space to vent but i could be wrong.

Any space between the top and bottom cords is "attic", whether it is usable as a space or not. You will want to have this vented as was mentioned in your first post. Yes, it is worth it.
Mark

 

[DougWil]

Down the road I plan to insulate the ceiling and putting up the metal panels rather than sheetrock. I was told the same thing about the condensation problem and not insulating the roof. With using scissor trusses I'm thinking there won"t be much of an attic space to vent but i could be wrong.

With scissor trusses and a low pitched roof there won't be much room for insulation either around the perimeter. Ice damming can also be a problem.

Basically you have decide which is better for your location, weather and humidity.
Vented attic or closed attic.

Suggest you do a bit of reading at http://www.greenbuildingadvisor.com/ and http://buildingscience.com/documents/digests/bsd-102-understanding-attic-ventilation

You also have to be concerned about a leaking roof trapping water between the roof and any type of spray foam up against the roof members/sheeting should you consider a closed attic.

 

[bkdawg61]

Thanks for the input guys. Anybody out there split there garage doors with a mullion?