How often do you change out bedding in your coop?

[Hudson]

I use wood shavings on the floor of my coop and want to know how often do you change out the bedding. I thought that I might just add more on top of the existing bedding but want to know if there are problems with doing this. Is it better to just shovel out all the old bedding and replace. The existing shavings have been in for about a month now.
Thanks for any info!

 

[CoyoteMagic]

I use the deep litter method. I only shovel, ok the hubby shovels, out twice a year.

Just add a couple inches ever month or so. If it seems wet, toss in some DE and scratch and let your chickens turn it over and dry it out for you.