Bark Chippings

[Charlotte01]

I have a large outdoor aviary which my guinea pigs can access. The floor was originally concrete so i sectioned off an area and made a raised herb garden but the rest of the floor is just concrete and I want to cover it with some sort of bark chipping. If necessary, I can remove the concrete slabs so there is drainage. I have looked at using hemp bedding however it is quite small and fine and I would like something slightly larger so i can keep it cleaner. It also needs to be safe for guinea pigs. Any suggestions....

 

[Swissgreys]

What about a nice, soft astroturf (fake grass)?
I have a friend who uses this for her elderly rabbits and it can easily be hosed down and kept clean, plus it comes in large pieces so can be cut to size.