Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays. With many questions to answer, please be patient to watch for yours to come up on a future Monday segment. If you want a quick answer, please be sure to answer with a “reply-able” email address.
Email all questions to: PoleBarnGuru@HansenPoleBuildings.com
DEAR POLE BARN GURU: Five years ago I bought a house and property that included one of your 48’ x 36’ buildings. For some reason, the brain-dead owner didn’t have it insulated. The fool even measured the building dimension to the inside of the corner posts rather than the outside.
Anyway, not knowing any better, I hired a contractor that removed all of the metal siding and roof and sandwiched 2” vinyl faced insulation between the sheet metal and the framing. Unfortunately, I now think this was an expensive mistake.
Since then I’ve experienced some leakage due to loose screws but the biggest problem after quite cold weather has been leakage that is dripping from the purlins at intervals that seem to be spaced where the screws would be. Needless to say, this makes the shop uncomfortable and nearly useless.
After reading articles on your web-site, it would seem that the problem is condensation between the insulation and the sheet metal and that I should have had your bubble wrap foil insulation installed between the sheet metal and the insulation I had installed.
I’m wondering if adding the foil insulation between the roof and the insulation I had sandwiched between the sheet metal and purlins will cure the problem or am I just totally screwed and have to start over?
Thank you so much for your help. EXASPERATED IN ELMA
DEAR EXASPERATED: It sounds like whoever put the building up was challenged….mostly by not reading the detailed plans and instructions which came with the building.
The “fix” will involve a lot of labor, but not a huge amount of materials.
Remove the roof and the vinyl faced insulation. Throw away the vinyl faced insulation.
Order enough A1V insulation to do the roof (www.buyreflectiveinsulation.com), 1-1/2” powder coated diaphragm screws to replace all the ones on the roof now, new ridge caps and vented ridge closure strips.
When you go to reroof – cut the first panel in ½ with the cut edge towards the endwall. The other ½ of the first panel will finish the roof at the other end. This will shift all of the screw holes by 4-1/2” so holes which have been elongated by being taken out and put back in will not be reused.
Make sure to use the adhesive tab to fully seal each strip of insulation to the next, as it is installed.
The vented ridge caps will allow warm moist air from inside your building to have a place to escape. If you have a concrete floor in the building, use a good sealant on top of it as well.
DEAR POLE BARN GURU: How can I get the most room and best use of the loft of a monitor barn…Need standing room and a 16 wide aisle down the center of the building. CAROL IN MANDAN
DEAR CAROL: You must have been thinking about this very hard, as I just this morning wrote an article on lofts and headroom.
For a monitor barn, plan the eave height in the raised center around this – add the height of the tallest door in the lowest level. Add one foot if the door is sliding, two feet for an overhead (this will give room for the door tracks, as well as the floor thickness). Add eight feet for loft headroom (code requires a minimum of 7’6”) and a foot for the roof system and any concrete slab on the lower level.
Example – 12 foot tall sliding door + one foot + eight feet + one foot equals 22 foot for eave height.
Be mindful to allow space for stairs. A hole the width of the stairs and at least 10 feet long is going to needed.
How do i cut down on condensation in a pole barn home? I am using spray foam insulation 6 inches in the ceiling and 3 inches in the walls. We also plan on having a wood pellet stove installed.
To cut down on condensation – go to the source – where is the moisture coming from?
Usually the culprit is a concrete slab on grade which has either no vapor barrier under it, or one which is inadequate. If this happens to be your case, the slab needs to have a high quality sealant over the surface (check with the Pro Desk at your local The Home Depot for recommendations on product). This will not be as good as the vapor barrier under the slab, but it is something.
It may be necessary to install a dehumidifier, if this does not resolve your challenges.