Our boiler lines and hot water lines are running from building to building through four 6" diameter sleeves (about 12ft long). They appear to be clay pipe but not sure. Anyway, rainwater now gets into all of them and, consequently, into our basements. We plan to replace with PVC but want to make sure we do it right.
We may increase the diameter to 8" Sched40 to accomodate thicker insulation around the boiler pipes. What's the best way to keep this new PVC 'conduit' watertight through our cement basement walls? What's the recommended method of support under the span (in Michigan)? And what considerations are necessary when burying them again? Thanks.