Spanky: They are sheets. For some reason, they won't show over the floor when flush with it. It's probably me just being a noob, but I did intend to eventually fix it. I thought about making the gate move, but it's there to show that you can't go back there. And thanks, I just built it real quick.
Ha ha. Okay bear with me because this could cause the editor to spit and flail its arms around. If you've used photoshop, you know how layers work. The top layer will show over the bottom layer. Almost the same story here in unrealed. You want the sheet brush to be "on top" of the brush its intersecting with. I don't have the editor up (and I'm too lazy to bring it up), but I think this is the process. Select the sheet and the subtracted brush it is flush with. Right click on either of the selected brushes so you can bring up the right-click menu. I think in CSG there should be a menu option called Swap grouping, layer, position, order, something. You basically click that option, do a build all and hope it works.
Let me recap that complicated wall of text. Your basically changing the order of precedence for two brushes occupying the same 3d space.