[jyl]

Oh, we didn't buy it. Seller had a higher offer, which was a relief to me.

Quick estimate: slate weighs 500 lb, 170 lb per piece. Add 150 lb for the wood. 650 lb plus say six teenagers at 150 lb each. That's say 1600 lb in an area of floor 10 feet by 5 feet.

On the third floor, more or less directly over my bed. Bedroom is appx 16 feet across in the direction of the joists. I have no idea what joist structure was installed when the attic was converted, it was permitted though.

Span calculator says need to be 2 x 12 joists up there assuming 40 lb / sq ft dead load and 10 lb / sq ft live load (which is actually more than said table and kids). How confident am I that was done?