Plans Only? Moisture Barriers? and Two Story Houses?

This week the Pole Barn Guru answers questions about “plans only” purchases, proper use of moisture barriers when adding insulation to an existing building, as well as the possibility or building a two story post frame house.

DEAR POLE BARN GURU: Do you offer just the plans? I own a sawmill and would like to mill my own lumber for my project. With the exception of the trusses. I can also source the metal roofing locally. THERON in WALDEN

Engineer sealed pole barnDEAR THERON: Thank you for your inquiry.

We are unable to provide just plans as it becomes a liability issue for our engineers – it takes away insuring materials specified actually end up being delivered to your building site.


There are also issues with attempting to use home milled lumber:

As an example, in sourcing your own metal roofing locally, even if steel quality was equivalent, they will not be able to provide powder coated diaphragm screws to attach it.

DEAR POLE BARN GURU: Purchased property with existing fairly new pole barn. Question is regarding wall insulation. Some installers say use double backed 6 inch glass rolls insulation under my drywall. Then I spoke with another & he says mandatory to spray closed cell foam or condition will ruin insulation…..there is no vapor barrier wrap on outside. Any help would be appreciated. Thanks, DAN in GRANBURY

DEAR DAN: You should have some sort of barrier between wall framing and wall steel to prevent condensation within the wall cavity. Wall cavity moisture can lead to a plethora of challenges – premature rusting of steel siding, rot, mold and mildew on wood framing and lack of performance of fiberglass insulation.


You could remove wall steel and add a Weather Resistant Barrier (highly labor intensive and things never go back together as well as they were originally assembled), or do a two inch coating of closed cell spray foam, then use fiberglass inside of it.

Here is my Ultimate Guide to Post Frame Building Insulation:

DEAR POLE BARN GURU: Hi there! I was wondering if y’all do two story residential pole houses? Second question, if I sent you guys a rough sketch of a blue print would you guys be able to give me an estimate off of that? (with included trim choices and such)

Thank you! MAX

Gambrel roof pole barnDEAR MAX: I happen to live in a two story post frame shouse (shop/house) with a partial third story. Back in the great state of Washington, I also have a three story post frame building with roof top deck! We can provide any low rise building with up to 40 foot tall walls and three floors (or 50 feet and four floors with sprinklers).


Send us what you have and chances are very good we can get you an estimate from it (we might want to ask you a few questions about what you intend to build).


5 thoughts on “Plans Only? Moisture Barriers? and Two Story Houses?

  1. Hello,
    I have built several pole buildings over the years and have always installed standard 1.5″ metal building insulation under the metal with no decking (purlin only), vented the ridge and installed gable louvers. We are planning a new house and shop, this time I plan to finish the ceiling with either drywall or maybe 29 ga metal. Can I just do what I have always done and blow insulation in the attic area when I am done with the ceiling.

    1. The gable/ridge vent combination is a very poor design solution as it does not adequately ventilate the entire attic. You would be better of with vented eave overhangs for the air intake. The Metal Building Insulation under your roof steel is probably not the best choice as it is difficult if not impossible to 100% seal the seams. My choice would be steel roofing with Condenstop/Dripstop factory applied. Use raised heel trusses to get full insulation depth from outside of walls to outside of walls.

  2. I have an 18×20 steel building with metal walls and roof. My builder didn’t install a vapor or moisture barrier. I am framing inside with wood. Would it be okay to attach wood frame to inside edge of steel frame then insulate inside the 2×4 frame cavity and then place moisture barrier before drywall? If so what type of insulation would work best there? Also what’s the best way to handle the roof insulation. I know spray foam is the best way but can’t afford to go that route. Also can’t remove panels to add moisture barrier because I’m working alone. Thank you for your assistance.

    1. To add to my above comments and questions, this ispace will be conditioned with a loft the in east Texas area. So winters aren’t too bad but we do get some freeIng weather but summers are close to 100 degrees for months.

    2. You want to entirely fill your wall cavity – space between steel framing members as well as 2×4 studs. Use Rockwool batts, as they are not affected by moisture. You are going to have to bite the bullet and use at least 2″ of closed cell spray foam directly against your roof steel, else be prepared for condensation issues.


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