I have a super-insulated house (18" thick walls, whole-house air infiltration barrier, insulated floor system, insulated foundation, conditioned crawlspace). I have a sump pit, but no pump (wasn't sure at build time whether it would be needed; it is).
I need to install a sump pump and an outlet to deal with high groundwater in spring thaw.
Most sump pumps have a 1.5" threaded outlet. Running 1.5" rigid PVC through the insulated floor system and walls will be painful; it will mean a lot of cutting, loose insulation dropping out of the floor, trying to glue a right angle inside an insulated floor system, and a large new puncture in the air infiltration barrier that helps keep the house warm.
I've been thinking of drilling a single diagonal hole (probably 24" or so) through the floor system in the crawlspace out to the exterior wall, and fishing some Pex through it. But I think this would require reducing the 1.5" sump outlet to a 1" or 3/4" Pex pipe.
A couple questions:
- I'm fairly confident that this diameter will adequately drain the water -- right now a garden hose through a window is doing the job. But I don't know if there are other reasons not to reduce a sump pump. Will it wear out the motor faster? Increase the chance of outlet pipe bursting?
- Is there any reason not to extend the Pex 10-15' from the outlet outside the house, to route it far away from foundation? It's a cold climate, so freezing is possible in e.g. May; but if things are freezing, then there probably isn't as much water to pump.
- Any other advice welcome. I've never sumped before.