pump up the jam
they finished installing the interior drain system today. couldn't really get any useful pictures, so instead here's a cross-section diagram of the system:
it's a really neat system...the drain holes they put in the wall yesterday stay there; whenever water comes through any of them, it gets routed under the concrete by the plastic spacer sheet (not quite sure what to call--it's a sheet of plastic with a bunch of square nipples on it to help keep the concrete slab from touching the footer or wall, but to allow water to pass through). then it passes through the gravel and into the drain. and when the water level rises from a storm or whatever, any water that tries to come up through the earth below will also find its way into the drain.
one unanticipated bonus of this system: since the concrete slab never touches the wall, that helps with the soundproofing by eliminating the flanking path that would otherwise exist between the two.
the only tricky issue is that the new concrete they laid down isn't as thick as the slab, plus the drain pipe doesn't sit terribly deep. this means that when i'm framing walls that pass over the drain, i can't use nails or screws. fortunately, nothing in the main room ever runs parallel to the drain, so i only have to worry about those places where it crosses over. the exterior wall shared by the vox booth and the storage room will have parallel-to-drain issues, but i'm entirely sure i'm going to frame along that wall anyway. i may just do furring strips instead.