crawlspace french drain: hug the wall?

[james]

I want to have crawlspace drainage installed. My crawlspace is approximately a rectangle with some protrusion (e.g. a dining nook).

When making crawlspace french drain, is it better for the drain to follow the foundation wall including all the nooks and crannies, or is it better to keep the drain straight, i.e. make a large rectangle that fit inside the foundation?

Two contractors proposed different approaches, and I wonder which one is better. The water is believed to come from the ground during rainy season (i.e. rise in waterbed), although this is not proven. The other possibility is leaky downspount drain lines.

Also, the sump pump will soak in water in a drain bucket at all time. Even though sump pump are designed to sit in water, I think they still last longer out of water. Would it be better to put a tiny hole at the bottom of the drain bucket, so that large amount of water still get pumped out, but standing water (below the water level switch) will gradually drain out and leave the pump dry?

The reason I believe the pumps last longer when dry, is because I once left a sump pump in a hottub for several years. When I pulled it out, all the fasteners (screws) have become rusty.

[bob haller]

as long as the drain field follows the general outline of the home it probably doesnt matter.............

any chance the drain could drain to daylight like the home sitting well above grade........

no sump pump is perfect, its best if you dont need one at all..................

[mike]

1. Fix all downspouts and have them drain far away from the house in a safe location.
2. The french drain (and drainage in general) should prevent your foundation from being saturated with water, not drain water out after the fact. Any trench should be outside the foundation so it can intercept and redirect water before it gets there. I doubt that the origin of the water is under the house.

[bob haller]

it can come from under the home.

although exterior french drain with new downspout lines is a easy job with a backhoe, and since the downspout lines should be addressed first, i would do the exterior now, then under the home if needed.

its best if the lines can run downhill to daylight, so as part of the exterior job run a dedicated line to under the home.

even if its not as low as the bottom of a future sump pump it can be a useful sump overflow / overfill line.

[Ken L]

My basement has a drain/sump system that was installed after the house was built. It follows the perimeter of the basement walls, on the inside, and works fine. As for the pump, I would say the pump is designed to sit in water and you should not worry about it. I have never had a pump fail due to rusty screws; the failure mode generally seems to be the switch. Besides, it will rust just as fast, maybe faster, sitting in moist air. --H