Ostrichsak
Well-known member
I took the OP's post to say that, if anything, the patio is uneven to the side that would create more drainage, not less. I don't think this is the issue unless I misread and it's uneven the other direction which could cause decreased drainage. Taking the OP's word at face value, I think we can rule rapid grease ignition out as the cause.I wonder how uneven the patio is? I would put a level on the grates and then on the drip pan to see if there is enough pitch to drain.
I would also put something under the wheels on the low side to get the grates level or leaning slightly to the grease bucket.