going foam in trench route for boiler run to house from barn. already have water line to barn but it will freeze if not blown out with air for winter. thinking of zip-tying or strapping a 3/4" domestic PEX line to the 1-1/4" return line that will be going back to storage. other than being a small heat sync until domestic line is heated up and potential supplying scalding water to barn, does anybody see a problem with this? i do not want to have to dig below the frost line and i am just looking to get freeze protection by piggybacking next to the return line.