Mold in new pole barn

[diamondeyes1002]

Not surprising. You have a sealed building with a dirt floor and cold metal on the ceiling. Warm moist air from the ground has no where to go and the moist air is condensing on the cold metal. Open the building and let it breathe till you have plastic on the floor.

110% not the contractors fault. What are you calling a perlin? House wrap on the perlins has nothing to do with this.

Sorry the headers . The boards the trusses sit on.

 

[Hank11]

Thank you we talked about that today . Maybe just putting plastic down and a layer of crusher run until we do the floor.

Think about this as prep for concrete — you don’t want to have to remove whatever you put down before you pour the floor. Talk to some comcrete guys about this so you don’t waste effort and money.

 

[billconner]

Do you plan or want the ability to insulate and condition (heat) space in future? The vapor barrier on the ground should be priority now and when you "finish" building. Not sure today's vapor barrier wont need replacing when you install slab.

 

[CraigStu]

This reminds me of a previous home of ours. Pretty standard footers and block foundation up about 2ft above grade. Over the years I had been on my back under there quite a few times doing wiring and propane lines etc. What I didn't realize was how important the plastic on top of the dirt was and how much I had messed it up. None of the joints had been taped so me sliding around on my back pulled a lot of them apart. 20yrs later we sold and had to fix all the mold that had grown on the floor joists. The official inspected and approved fix was spray all the wood w/ a mold encapsulating paint, new plastic well taped on the dirt, and 4 more blocks replaced w/ vents, one of which had a humidity controlled fan installed. So for the OP's barn, I'd lightly spray the current mold so the chemical can work on it but not drip off to the ground, seal the dirt 100%, install something like an attic fan (or 2) on one end and air inlets on the other end.

 

[05snopro440]

I have a 32x42 tarp quonset (half round with a heavy duty tarp roof and back wall, steel front wall with roll up garage door and steel man door). It has a gravel floor and is far from airtight, but with the doors on the front closed it limits airflow.

It would rain in the building due to condensation not just on warm days, but anytime the weather changes, the sun shon on it, etc. During the summer there would be days there was water dripping off of the vehicles in there, and the moisture would be so much it would literally rain in there.

I put a 10" whirlybird roof vent in the front wall and 95% of the condensation is gone.

Until the building is sealed from moisture and condensation (insulation, concrete floor), you need a way to get air flowing through the building so that you don't get condensation inside it. Some use powered fans, but you need something that will allow air in and something to allow air out.