Hi, we have a new built home and at the side is a termite reticulation (circled red) and pit (circled blue).
I am required to place enough material to cover the termite reticulation system (as part of the certification inspection process). I don't know what I can do to achieve that, yet prevent weeds from sprouting again in the future. Do I need to place edging all the way along side of the house wall? How do I prevent material from dropping into the pit (and thus clogging the pit) - do I use edging to box around the pit?
I heard something about sandy loam mixture and maybe decomposed granite but I have never used them before. Will using these all along this side of the house achieve the above? Which material comes first or is just one of them sufficient? The reticulation pipe looks quite high above the ground so it does look like I have to purchase quite a lot of the material?
This side of the house slopes downwards from the back of the house to the front therefore, I don't think I am able to make it pretty by putting pavers and the like....
Any suggestions greatly appreciated. Thank you.

It slopes downwards from back to front