Sorry for the delay.
Spot and Listen, just in case.
Spot:
(1d20+6)[19]
Listen:
(1d20+8)[24]
Now checking the floor for traps. It'll take 12 checks to do the entire floor. Wellby will do the outer 10'x10' sections first, moving clockwise, then do the two remaining inner sections. Then he'll do the walls, then the coffin.
Search the floor for traps:
(1d20+18)[30],
(1d20+18)[20],
(1d20+18)[28],
(1d20+18)[27],
(1d20+18)[35],
(1d20+18)[28],
(1d20+18)[32],
(1d20+18)[30],
(1d20+18)[30],
(1d20+18)[28],
(1d20+18)[34],
(1d20+18)[33]
Search the walls for traps:
(1d20+18)[23],
(1d20+18)[25],
(1d20+18)[26],
(1d20+18)[31],
(1d20+18)[23],
(1d20+18)[21],
(1d20+18)[32],
(1d20+18)[28],
(1d20+18)[33],
(1d20+18)[25],
(1d20+18)[23],
(1d20+18)[30],
(1d20+18)[37],
(1d20+18)[24]
Search the coffin for traps:
(1d20+18)[25]
And now for secret doors!
Search the walls for secret doors:
(1d20+20)[22],
(1d20+20)[22],
(1d20+20)[40],
(1d20+20)[37],
(1d20+20)[34],
(1d20+20)[22],
(1d20+20)[27],
(1d20+20)[22],
(1d20+20)[38],
(1d20+20)[37],
(1d20+20)[36],
(1d20+20)[30],
(1d20+20)[28],
(1d20+20)[26]