With this modlist, you cannot build on top of underground pipes (with some exceptions like elevated rails):
{
PlanetsLib = "1.2.12",
base = "2.0.32",
["elevated-rails"] = "2.0.32",
janus = "1.1.1",
quality = "2.0.32",
["space-age"] = "2.0.32",
["the-one-mod-with-underground-bits"] = "0.1.4"
}