OOC:
Describe me how do you check for traps.
Now as you know what to look for you will be able to discover unstable floors without skill checks. If if there is something different, like a swinging log - you will certainly miss it without light source. Maybe even with the light as you don't have anyone with high PP in the party.
However should you let's say roll a log into corridor there is a chance to trigger that log trap and since you are away from impact point it will not hurt you. But as you could guess there are no log traps - I would use them as example. You have no idea what traps are there and if there are any more than one.