Much better. I'd still expect the quartz to crack when someone does something dumb. With 30 lbs/ft distributed and 300lb point load in the centre (a 200 lb person climbing up will be more than 200 lbs force), deflection of your design will probably be >0.2 inches. With something that long it is conceivable that more than one person is on it at a time (staff hanging decorations, drunks, people that sit on the counter and look out etc). A steel skin over the bottom of the frame would really stiffen it up.Damn dudes, you guys brought up some excellent valid points
Guess I’ll have to shell out the extra cash for a welded custom steel base.
How is:
a rectangular box constructed of
Three 9ft 2x2 steel square tubes, 1/4” walls. 1/2” plywood laid and screwed on top (stone directly on steel would crack)
The legs will be 1.5x1.5 steel square rubes with 3/16” walls on each end.
I haven't checked this calculator to see if it is accurate but the results pass the smell test.
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