Tough matt forming plants for damp shade

What I've done so far is laid loads of bricks in it, sort of to make a brick floor. I've not cemented them in or anything, as my plan is to be able to just lift them back out if I need to. I've left two large squares without bricks, where currently the two fatsias are planted.

I did it this way partly because I needed to fill it with something, because it was just bare earth, and partly because I had three sacks of old bricks taking up space.

Trouble is, I've run out of bricks before its finished. Straight over the road from me, a neighbour has had loads of old bricks piled up against a fence in her garden, where they've been for at least a couple of years, and as she doesn't seem to be interested in her garden apart from it being a place to park her car, I suspect she doesn't want them, so I might try to pluck up the courage to go and knock on her door to see if she will let me have some.