Tag Archives: moisture

A Garage Apartment, A Moisture Problem, and Insulating a Ceiling

Today’s Pole Barn Guru answers questions about building a garage apartment aka a “Shouse,” how to address a moisture problem, and the best way to add insulation to a ceiling.

DEAR POLE BARN GURU: Can I design a garage apartment pole barn? JAY in HINTSVILLE

DEAR JAY: You may not have this ability however we have experts who can assist you. To develop a workable custom floor plan, designed specifically to meet your wants, needs and budget please use this link: http://www.hansenpolebuildings.com/post-frame-floor-plans/?fbclid=IwAR2ta5IFSxrltv5eAyBVmg-JUsoPfy9hbWtP86svOTPfG1q5pGmfhA7yd5Q


DEAR POLE BARN GURU: Live in the Midwest, have a 54 x 36 pole barn well insulated, walls, and ceilings. When it rains a lot I have a moisture problem, My building is approx. 1950 Sq. Ft. I found a dehumidifier that covers 3,000 sq. ft. I was thinking about putting one in the pole barn, it can run continuous if I put a hole in the side, for a drain, and let it drain out, just leave it running on its own as it needs to. Is this Ok to do to solve my issue? RON

DEAR RON: A dehumidifier may resolve your building’s symptoms, however not its problem. As this is a function of rain, I am led to believe you need to eliminate or reduce your moisture source. If your building does not have a vapor barrier under your concrete floor, seal top of floor. If you do not have rain gutters install them and ensure runoff is directed well away from building. Make sure ground outside of building is sloped away at least 5% for 10 or more feet.


DEAR POLE BARN GURU: I have a 32X46X15 pole barn with purlins attached to the outside of the 6×6 beams. The barn has soffits and a vented ridge cap and is set up for a ceiling. I have since decided to keep the rafters exposed and have questions about sealing up the soffits and ridge cap but leaving several small openings in the ridge cap to allow for humidity to escape.

How much should I leave open on the ridge cap and should I totally seal off the soffits? Will it be ok to leave the beans and rafters exposed, putting a vapor barrier in between the beams and the rafters?

What are your thoughts on 2in foam with no vapor barrier glued directly to the metal in between the purlins every 2feet? Then another 2in foam board with a vapor barrier placed on top of that screwed to purlins and can spray foam the edges and gaps? Thanks for all your help! MARK in VALPARAISO

DEAR MARK: My response is with a thought you are trying to climate control your building to some extent. Your proposal to use two inch-thick foam insulation board sounds to be highly labor intensive as well as being fraught with challenges in trying to achieve a complete air seal. Any air gaps would allow for warm moist air from within your building to not only condense against your building’s steel cladding, but also to remain trapped there, potentially being a cause of premature degradation of steel panels.

I would recommend you look towards closed cell spray foam as a solution for both insulation as well as condensation control. You will want to completely seal both eave and ridge then have at least a two inch thick layer of closed cell foam sprayed on interior face of roofing and siding. A mechanical dehumidifier should be used to control relative humidity with your building.





Electrical Planning, Moisture Issues, and Ceiling Barriers

Today the Pole Barn Guru fields questions on electrical planning, moisture issues, and ceiling barriers.

DEAR POLE BARN GURU: Good Morning/Evening:     I currently have a 36′ wide x 48′ long with 12′ tall ceiling pole barn that I would like wire for lights and outlets.   I intend to run main power from the street pole to a meter base and into a internal breaker box.  I know you have/sell electrical planning layouts for the internal pole barn light/outlets and I would like to purchase a set for use as a general guide.  Can you tell me how I might purchase your pole barn electrical layouts, etc.??    Thanks for your help in advance.   Very Respectfully. BILL in AMHERST

DEAR BILL: Thank you very much for your inquiry. We do not involve ourselves in any sort of electrical. No electrical materials, no layouts, no plans. Try visiting the ProDesk of your local The Home Depot for assistance.


DEAR POLE BARN GURU: Hi I’m emailing because I’m having issues with moisture in my building it happens when it freezes and then thaws and it only drips from the pillars and I have moisture barrier inside can you please explain why that’s happening. ROBERT in CHEHALIS

DEAR ROBERT: We receive a handful emails with challenges such as yours every winter, from clients who recently had their buildings completed. It all goes back to where is moisture source?

If no concrete slab in your building, it is because ground outside of your building freezes before ground inside. When this occurs it is like pulling a cork from a bottle – all ground moisture from area surrounding building tries to escape through your building.

Have a fairly new slab on grade in your building? Moisture will be coming from it. As long as you have a well-sealed vapor barrier under your slab, you should only experience this issue for one winter. You can speed this process along by keeping large door(s) open on days when dew point stays lower than outside air temperatures (lower humidity, faster water will exit your slab).

If a well-sealed vapor barrier was not installed under your building’s slab, then slab surface should be sealed (once it dries out).


DEAR POLE BARN GURU: Hello. I plan to use foil backed foam sheets for my ceiling in my 28 x 34 Pole Building / garage. Reading your article, you would NOT put up a plastic barrier to control heat loss before hanging the Foam board? 4 / 12 pitch. Recommendation for hardware to secure sheets to trusses?
Thank you DAN in BUTLER

DEAR DAN: A plastic barrier would not make any difference in controlling heat loss, as it has no insulating value. Your foam board, if installed properly with joints sealed, will act as a vapor barrier. I’d glue it to truss bottoms to eliminate transfer of heat through nails or screws. Make sure to adequately ventilate dead attic space you are creating and a provision for preventing warm moist air from contacting roof steel underside exists.