I had a new boiler installed in garage. I wanted the condensate pipe to go into a nearby gutter downpipe but it all froze up last winter so the boiler couldn't discharge. The downpipes are old cast-iron (and have split). The problem is the downpipe goes straight under the path i.e. is concreted in. If there was a drain cover at the base I assume I could just route some polypipe from the boiler condensate to the existing cover. Can the base be converted i.e. could you crack open the concrete and put in a drain cover which I could then add the boiler pipe?. I could then change the gutter downpipe to plastic at the same time. Is it put underground to try to prevent freezing up in winter?