4 inch drain pipe
If you have holes in the pipe it will not carry the water away, especially for low water flows. Just as it makes little sense to try to slope a perforated pipe. - A perforated pipe is just a collector.
It can actually work in reverse since water can enter through the holes, fill the pipe and back up unless you have a very, very steep grade.
Not a good move!
If it is from a downspout, it should be at least 10' away from the house. You can use a pop-up if you don't like the looks. The pop-ups are not foolproof when it comes to backflow. It is hard to beat draining to daylight, a large drain pit or a "french" drain downhill.
Last edited by concretemasonry; 05-15-2007 at 05:54 PM.