What’s up with the mildew inside new coop?

[Duck Hill]

I definitely think you need much more ventilation. The ceiling can hold in moisture even if the door is open. I live in a humid area and my closet has done the same thing even with an open door, because there is a space above the door that holds moisture. Hens generate a tremendous amound of moisure with their breath and droppings, so your coop would get mold faster than my closet.

My coop has four open sides for the bottom 18 inches or so (hardware cloth). Then it has two openings on top (again, hardware cloth). This has worked down to about 10 degrees F. The fact that light winds travel through the coop keep it dry, yet the sides slow down the wind enough that the animals keep their warmth in winter.

 

[Birdsong 82]

All I did was wipe it once with a dry cotton rag. And here’s the color. I wonder how I figure out if it’s mildew or not

 

[Birdsong 82]

I definitely think you need much more ventilation. The ceiling can hold in moisture even if the door is open. I live in a humid area and my closet has done the same thing even with an open door, because there is a space above the door that holds moisture. Hens generate a tremendous amound of moisure with their breath and droppings, so your coop would get mold faster than my closet.

My coop has four open sides for the bottom 18 inches or so (hardware cloth). Then it has two openings on top (again, hardware cloth). This has worked down to about 10 degrees F. The fact that light winds travel through the coop keep it dry, yet the sides slow down the wind enough that the animals keep their warmth in winter.

The weird part is is the fact that they are very rarely in there. They’ve only been sleeping in there for a couple nights now and my chickens just always have preferred to been outside. Even when it’s raining. They’re so weird. We had already been thinking about adding an extra window beside the one that is there just because of how hot it gets in the summertime here. It has an A-frame roof and the top of that is open with HC It’s about 2 foot and then tapers down to about 6 inches and then there is 6 inch openings along the top on the 2 8 foot sides. The window is about 2x 2.5. The doorway is open till a few weekends from now. I’m going to make the door so the top and bottom can be opened separately. So to keep ventilation

 

[Birdsong 82]

And the fact that it’s on the outside of it as well. I could understand if it was mainly on the back on the outside where it is near the woods but it’s just as bad on the front where the sun is hitting it almost all day

 

[Soon2BChixMom]

Well, mildew and mold are both fungi. It looks like a type of fungus on your cotton cloth.
It's obviously not a ventilation problem. Since it is on both the inside and outside.
Here are some tricks for mold on the outside of a house.
https://www.todayshomeowner.com/video/how-to-remove-mold-on-the-outside-of-a-house/
How many coats of paint did you use?

 

[Birdsong 82]

I used 2-3 coats. The barn paint is pretty thick. Most of it has three but I got sick before adding the last coat on one of the sides. So I haven’t gotten back to that. But I probably didn’t need to add three anyway. I was thinking a coat of sealant of some sort or a different paint. I’ve used the barn paint on many things and never had a problem

Well, mildew and mold are both fungi. It looks like a type of fungus on your cotton cloth.
It's obviously not a ventilation problem. Since it is on both the inside and outside.
Here are some tricks for mold on the outside of a house.
https://www.todayshomeowner.com/video/how-to-remove-mold-on-the-outside-of-a-house/
How many coats of paint did you use?

 

[Soon2BChixMom]

Yeah. I used barn paint on the inside of mine and don't have any issues. I wonder if the location is the problem? Just very odd.
Do you have any buildings near this coop?

 

[aart]

I was thinking a coat of sealant of some sort or a different paint.

Adding more paint is not going to change anything,
the organism is in the air, as is the moisture, it lands on surfaces and 'grows'.

Did you other structures have this problem?
Wonder if you take a dry, unpainted piece of wood and lean it up again where this stuff is, and see if it 'infests' a fresh bare piece of wood. Just a thought.
As annoying as this may seem, wonder if it's really harmful?

 

[Birdsong 82]

Just The smaller coops which is doing fine. They are all much smaller. The only other ones are quite a bit away.

 

[Birdsong 82]

It doesn’t seem to smell in there. I’ve been keeping up on wiping it cause thought it could be harmful for the chickens who are thankfully in there very seldom. Hopefully not harmful to them. And if it’s not still don’t want it to damage thier new pad. Took us a long hard time to build that and they seem to like it when they are in there. I’m gonna give the plain dry wood a test. The coops on the other side of the run aren’t right up near the woods like this one.