I am planning out an underground sprinkler system and need to bore a hole through a concrete foundation wall to bring 3/4" copper pipe through. The point where the pipe will come through is above grade, and in a northern/freezing climate. The concrete foundation is roughly 90 years old.
I've read elsewhere that you need to drill a large enough hole put in a PVC or ABS sleeve to isolate the copper from the concrete. Is this really necessary if the concrete has already been poured/cured? Is the purpose of the sleeve only meant to save you from having to drill after pouring new concrete? If the concrete's already set (and foundation is settled), then I don't really see a need for a sleeve. I would just drill a slightly larger hole (maybe 1" or 1-1/4") and pack the annular space with silicone or expanding foam. Does this sound reasonable?
I've read elsewhere that you need to drill a large enough hole put in a PVC or ABS sleeve to isolate the copper from the concrete. Is this really necessary if the concrete has already been poured/cured? Is the purpose of the sleeve only meant to save you from having to drill after pouring new concrete? If the concrete's already set (and foundation is settled), then I don't really see a need for a sleeve. I would just drill a slightly larger hole (maybe 1" or 1-1/4") and pack the annular space with silicone or expanding foam. Does this sound reasonable?
