Anyone retro-fitted a perimeter drain from sump to daylight?

[mele63]

I recently had a problem with an inadequate sump pump causing my basement to flood. I'm seriously considering excavating down to the footing and tapping into the perimeter drain and running it to daylight - I have the grade for the daylight drain (why the builder didn't drain to daylight is a mystery to me).

Any pitfalls/advice from those who've been there, done/tried that?

[LazyPup]

Creating a natural gravity flow drain would always be preferrable to using a sump pump because you have no energy consumption, maintenance or risk of system failure from a power outage, however making the conversion is not quite as simple as just digging a trench and connecting a line.

You must keep in mind that the existing footer drain surrounds the entire structure and by necesssity it is pitched to insure any water entering the system would flow to the point where it presently connects to your sump pit.

As a consequence your gravity flow line will need to connect to the existing footer drain at the low point, then flow away with a continued downhill pitch.

The code minimum pitch for a 4" line is 1/8" per foot however we must keep in mind that the velocity of flow is directly proportional to the pitch. In a nutshell the greater the pitch the faster the flow.

In addition to pitch our choice of pipe material can dramatically effect the velocity of flow. While corrugated flex pipe is without a doubt the least expensive material we must keep in mind that the corrugated wall will greatly increase line friction. Whenever we have terrain conditions that might make creating a higher pitch difficult a much better choice of material might be 4" PVC SDR-35 or PVC sched. 20, sched 30 or sched 40.