This is how I put in my patio supports. First a quick explanation on the difference between a patio and a loft. They are pretty much the same thing, only a patio is placed above the ground level 1/2 a grid high up. It doesn't require extra grids or a second higher level like a loft does.
My cage has a patio. It starts with support bars to hold up the patio. For my support I use wonder bars from the guinea pig cage store (you can find them here: http://www.guineapigcagesstore.com/candc-wonder-bars#.Ut7wyXn0BhA ). You can also use a 1.5"x1.5" piece of wood, wood dowel, or a broom handle. Just make sure you cut it down to size and then add a stopper to the end to stop the wood from slipping out and falling down. You can do just one support bar and two grid supports instead. There are lots of ways to set up a loft but this is how I did mine. Its very sturdy, cheap and easy to do.
On top of the support bars I have a support grid cable tied to just the right side of the cage (not the back). I use another grid bent into a U shape for my ramp. The ramp is cable tied to the grid. Doing it this way means that all my supports are removable and swing up out of the cage for cleaning.
Here's my supports propped on my wonder bars:
Here is my grid support and ramp up and out of the cage for easy access.
My wonder bars have also been removed in this photo:
Pretty cool huh?