Oh yeah, and some will consider this as a humorous aside to the topic of sealed chambers...................

Don't build a thermal glider with solid ribs. Make sure the ribs have holes in them. Breathing holes if you wish.

Years ago, a number of glider buddies and I hit The Perfect Day. Everyone specked out and some went really, really high. Blue sky with about 60-70% bright white puffies WAY up. Keep the speck between the white and you and you could still see it. Get it out in the blue and you could lose that speck.

One guy had built a really tight wing. He'd even painted the ribs to give them extra strength. He also had good eyes and had violated one of our guidelines on "how high is safe". With a glider, when it specks out, you don't see the shape anymore, just two specks. A "long" one with a tiny one beside it. The long one is the wing, the tiny one the horizontal tail. As long as you can see both, you're not too high. When you can only see one, it's time to spin or spoiler or flap the sucker back down some. So he'd showed up when everyone was up at two dots high. Threw the glider on the winch and made a climb to altitude record attempt to get up with us as fast as he could. And in the process went to one dot almost right away. So he tries to come back down and discovers his spoilers aren't connected. So he spins the sucker all the way back down.

Turns out one wing has some split covering. Like it'd blown out from inside pressure. When we heard about the sealed ribs and saw no holes, we decided he had blown that covering out. By flying all those potential balloons up into lighter and lighter pressure.

You know old stories are fun sometimes.
Just remember, the older you get, the better you were.