How do I install a door in such a tight, slanted space?

Slanted doors under a staircase are a nightmare to frame if you try to use a standard pre-hung approach. Since you've already got the drywall off, the easiest way to handle that bar-side entrance is a **flush-mount pivot door** integrated into your paneling. Instead of a traditional side hinge that will bind against the angled ceiling, a pivot hinge set into the floor and the header allows the door to rotate inward. If you match the bar paneling exactly, the vertical seams just look like decorative trim.

If you go the closet route, knocking out that back wall is the most practical for storage, but it kills the 'secret room' vibe. If you want to keep it as a feature, I'd suggest a **Murphy door** (the bookshelf style) at the back of the closet. It’s easier to install than a custom angled door because you’re working with a standard rectangular opening, and it adds a second layer of 'hidden' to the space. You lose about 8-10 inches of depth for the shelf unit, but it makes the entrance look intentional rather than a DIY hack.

Since you found wiring in there, definatly check the gauge before you hook up a fixture. If it was just a rough-in for a pull-string light, you might want to upgrade it to a low-profile LED disc light so you don't lose any of that precious headroom under the stairs. And since this whole project started because of a flood, make sure you seal the concrete floor with a high-quality vapor barrier or epoxy before you put any new finishes down. I've seen these spaces turned into wine cellars or humidor rooms which would fit perfectly right next to your bar. If you go that route, use moisture-rated green board or even cement board for the walls instead of standard drywall. Even with the pumps fixed, sub-stair spaces are notorious for trapping humidity, so adding a small vent to the door or a passive wall grate into the closet side will keep the air from getting stagnant.

If you're going the bar paneling route, don't mess around with cheap hardware. Grab a set of Sugatsune HES3D-120 concealed hinges. They’re 3-way adjustable which is a lifesaver when you're trying to line up seams on a custom angle. For the 'secret' vibe, skip the handle and install a heavy-duty magnetic push-trigger so the panel stays flush.

Since you mentioned the flood, check your floor clearance. I’d leave a 1/4" gap and install a Pemko 411ARK automatic drop seal. It stays retracted so it won't scuff your finish, but seals tight when closed to keep basement dampness out of the hidden space. It’s the professional way to manage a custom setup like this.

Listen to the guys about the hinges, but back in the day, we’d just skip the fancy pivots and build a 'Dutch-cut' jib door. If you frame it right into the bar's wainscoting, you don't even need a header. Just use a simple Soss hinge—the invisible kind we used before everyone got obsessed with those overpriced kits. Just make sure you leave a hair more gap at the top of the slant than you think you need. Houses settle, and those under-stair spaces are the first to pinch a door shut when the seasons change. Are you planning on running a sub-floor or just keeping it concrete?

Don't forget about the floor transition if you're doing a secret door near a bar. I've seen guys nail the paneling but then a thick rug or a wierd tile gap ruins the illusion. If you're sealing that floor post-flood anyway, keep the finish seamless trough the threshold. Also, if it's gonna be a wine nook, you'll want a magnetic gasket on the door edge. Keeps the temp steady and stops the door from rattling every time someone walks by the bar.