Originally Posted by Paulie Boy
Drainage pitch for the slab should be 1/4" per foot.
1/4" per foot might be okay for sewer drains. I used it for my concrete patio and is the worst thing I could have done (2.5" over 10ft is way too much). A minimal slope is all that is necessary since even the flatness finishes have dips that you want the slope to drain these pools. Nobody wants puddles!
For a 40 ft MH will have about 30' between front and rear tires. Using 1/4" per foot will mean 7.5" difference between front and rear. I have seen not so nice campgrounds with flatter camp sites that that. I would not want to spend all that money for a concrete pad and end up with a ski slope.
Might be a good idea to pitch downward from the center both ways; either lengthwise or side to side (like some roadways, with a crown in the center)