depth of rain water run off drain pipe.

[JerseyMike]

hey guys, i have a large driveway that displaces a large amount of water when raining heavy. there are down dpouts from the house and the garage in the back and the driveway/patio is pitched to the grass. i want to put in an in ground drain and 4" pipe to make the flow go elsewhere. the drain in about 4"deep and w/ a 90 elbow off of the bottom, i'm guessing the overall the pipe will be about 12" below grade, then i'll make myrun of pipe to discharge the water.

my main question is, since i love in NJ and the winter can be cold do i have to worry about the line freezing up or will it be deep enough no to have a problem. i know as long as there is zero standing water in the discharge line there is nothing to actually freeze, but before i go digging in the spring and reseeding grass where i need to, is there something i'm over looking??

mike..........

[Norminn]

I'd be inclined to go to the city building department and run it by them. Need a permit ennyhoo, right?

[JerseyMike]

permit for what??? it's rain water i want to runoff into a drywell or out to the street.

mike..........

[PJx]

Some people like BIG GOVERNMENT that controls every aspect of their lives and some don't.

I don't.

[B]

I am guessing that if the pipe freezes below grade, there won't be any surface water to flow into it anyway, and if the surface ice thaws before the pipe, so you'll have a little flood for a day. Would that work out for you?

-B

[David Efflandt]

If you have multiple gutter drains plus driveway/patio runoff, you may need larger than a 4" pipe. If it is NOT below the frost line, it may freeze (which if not large enough or drained completely, may plug and/or split it), and frost heaving may eventually shove it out of the ground (although, that may take years).

Water expands with tremendous force when it freezes.