Play structure/ jungle gym on concrete patio - what to put under it (cost, best)

[mkarch]

We've set up a play area in the back yard and half of it is concrete due to the yard layout. We're going to need some sort of soft landing pad under the play structure. We have cats, as do the neighbors so whatever we put in needs to be unattractive as a litter box. We're in Seattle so it rains a lot, so whatever we put in has to be somewhat unaffected by moisture.

Removing the concrete patio isn't an option as it's a structural part of the overall retaining walls, etc. The part that isn't concrete is lawn and we don't want to give that bit up since it's the only lawn on the property.

Rubber pads or shredded rubber seem like the best option - any tips on what to look for or specific products? Cost is a factor but I'd be willing to spend a grand or so to prevent injuries.

[bus man]

I think a spongy rubber matting is going to be your best bet. Google "playground matting" for a wide variety of choices. Since they are made for outdoor use, in theory they should be rain-resistant.