is this mold or fungus? or what?

[Jenbirdee]

my ancient original coop and run combo still standing, so I leave the door open for the chickens to go in to get out of the rain during the day, but nobody sleeps in it. what is this? is it time to tear down the old run?

 

[Jenbirdee]

my ancient original coop and run combo still standing, so I leave the door open for the chickens to go in to get out of the rain during the day, but nobody sleeps in it. what is this? is it time to tear down the old run? View attachment 3839901

by the way it’s not the only rain shelter in the yard . My chickens usually go under my pool ramp on rainy days or they hang out in the big duck house lol

 

[aart]

Probably some kind of fungus.

 

[SandyRiverChick]

Looks like the wood and tree fungus we get here in the PNW. There are treatment chemicals but my Go To is just Kilz paint. I'd just scrape off, sand, then put a thick layer of Kilz on it. I know Kilz is not the end all, be all but it definitely keeps my old wood alive for much longer than with out it.