Serious mold problem with Playhouse coop and sand

[Underwhere]

I built my playhouse coop out of a little tykes playhouse. I put a wood floor on it and did my best to seal all windows etc.
I've been using pine shavings about 4-5 inches thick and after a while the bottom gets very wet.

Last week I switched to sand to see what it would be like.
I'm not sure if rain is somehow getting in but in some areas the sand is completely soaked and I am getting what appears to be mold.
The mold seems to be growing literally overnight. The picture below literally appeared overnight. 9PM yesterday I closed up the coop. I checked on them at 7PM today.

Any suggestions?

Are people getting wet sand in their coops? The top layer may dry a bit but under 1/2 an inch it seems wet.
Would a fan blowing on the sand help?

 

[emys]

I think you closed it up too tightly. You need more ventilation towards the top to help things stay dry. In such an enclosed space, it could be moisture from the chickens themselves breathing out moist air.

The moisture condenses on the top and rolls right down the walls to the floor.

 

[True Grit]

I think rain must be getting in if first your shavings and now the sand gets wet INSIDE the coop. Is your coop is plastic ? And you say you sealed the windows. What do you have for ventilation? Condensation could be running down the walls.

 

[Underwhere]

It could be rain from the coop door. That is the only door that is not sealed.

There is no condensation on the walls at all.

I sealed the bottom of the coop (board to the plastic walls)
I sealed the windows (clear plastic)

Maybe I will put a fan in there tomorrow. I think it needs a big revamp.

 

[True Grit]

Like emys said, you need some ventilation, open windows or whatever - 1 square foot of ventilation per chicken, covered with hardware cloth so the predators can't get it. It is good to have an overhang over the windows to keep the rain out.

 

[Underwhere]

The roof has about 1/2 inch of space all around the coop which I assumed was enough ventilation

There are 3 lexan windows (all sealed) pictured here.
There is a 2x2 foot overhang over the front door now (not in pictures) but no sides to it.
I am considering adding sides.

 

[True Grit]

It is super cute! I don't know that you would get much condensation but you could need some more vents, depending on your temps. Maybe you'll have to go out and observe while it's raining to see if it is coming in. If not, then more ventilation.

 

[Underwhere]

The coop doesn't show it in the pics but I put hinged windows in there.
I'm going to remove some of the sand and see if it dries up. Maybe I layered it too thick (4 inches)

 

[gale65]

I'm almost positive I saw a post a while back about someone who revamped a playhouse and was getting soggy wet bedding for no apparent reason.

 

[GhostRider65]

If it's getting very warm during the day and cooling off at night, you would be surprised how much sweat forms on plastic, I would try some more vents, a fan add some DE to the sand to help it dry a bit more, I would toss all the wet sand you have, and start over after the vents are installed, Mold is bad thing for anyone even your chickens can get a bad lung infection from it.
Super cute house/coop though.......