Pole barn - ventilation with no soffits

[twosocks90]

I am planning to insulate my pole barn. I want to install metal liner panels on the ceiling with insulation (blown or batt) on top, and then use rigid foam on the walls. Spray foam is out of budget - it costs too much.

The building has no soffits but it does have a continuous ridge vent. How do I ventilate the attic space considering there is no place to get air into it from the bottom? I don't want condensation up there to drip down into the ceiling insulation and ruin it.

 

[75gmck25]

Soffits are the best place for air input into an unconditioned attic with a ridge vent (its the lowest point for natural ventilation) , but the other common choice is a couple of square gable vents.

You could also add a temperature-controlled exhaust fan to one of the gable vents. There may be an option to use a controller that turns it on based on humidity, but I've never looked for one.

Bruce

 

[gphil12873]

I was searching for this exact thing this morning. Im fixing to start mine and this thought went thru my head.

 

[twosocks90]

I looked at another pole barn similar to mine. The builder installed faced fiberglass between the posts, covered the whole wall with plastic, girts on the inside then put the metal walls over that. Nothing else for ventilation into the attic.

I wondered if there could be enough air leaking in at the bottom of the walls where the metal ribs stand away from the wood. It would be like little tubes carrying air from the bottom of the exterior wall up into the attic space.

 

[3rdgendslmech]

I dont think that's gonna be enough twosocks. Are you planning on putting a ceiling up? If you are you could put a gable end vent on each end.
What about reversible flow ceiling fans?

 

[Ryan Wilke]

Twosocks90,
Do you plan to heat the building or are you simply trying to keep the temperature 'swings' to a mininum?

Ryan

 

[twosocks90]

3rdgen - I plan to install a metal ceiling with blown or batt insulation on top of it.

Ryan - The building will not be heated 24/7, but it would be nice to be able to go out there on a cold day and use a torpedo heater to take the edge off. As it is now, any heat I put in is instantly lost.

 

[brianpgriset]

Bumping this thread. Looking for answer to the same question. Looking at a building with no soffits, the eaves and flush with the walls. Just the plain eave ends of the metal roof. There will be a continuous ridge vent. How do you get air in the bottom?

 

[Marctrees]

The foam strips that match the panel profile are called "Closures"

In addition to the best known foam ones, Closures are also available made of like very coarse and open scotchbrite pad type material... made to pass air.

Those are used under ridge cap, and at bottom end of roof panels to pass venting air.

Marc

 

[Marctrees]

Examples - https://www.bestmaterials.com/detail.aspx?ID=23115


https://www.plyco.com/Content/PDFs/QuickFoamVent.pdf


https://marcoindustries.com/products/ventilation

 

[brianpgriset]

Marc - the thanks for the links. I saw the ones for all the ridge vent profiles but none for the open ends of the eaves despite all my searches. You have links to any of those?

Really curious if those will be enough for a lower vent in terms of surface area.

It's making me think I'll be stuck with a gable vent. Although I've noticed NONE of the metal buildings Seoul here have soffit vents but do have ridge vents. Perhaps it's not as big a deal on my area since we really only cool and rarely heat our buildings?

I also thought the rule of thumb for this type of venting was to have slightly more bottom vent than top?

 

[Marctrees]

Beaumont, TX is definately hot humid climate.

Many folks, including me if planning to AC, seem to be going w NO passive venting and spray foam of walls and under roof.

"Sealed" building envelope concept.

We were going to go w the vented closures but then learned the sealed method seems to be best.

Marc