When building your own home, the plumbing is topped out in accordance with the plumbing provisions of the International Residential Code after the homes frame is complete. The plumbing contractor furnishes all material for this work. As the owner builder, it is your responsibility to check the contractors work for any change orders that you may have executed with him for changes, extras, and additions to your home. At this time, the plumbing contractor constructs the drain, waste, and vent (DWV) system, venting all plumbing drains out the rear or sides of the roof. He will also install all hot and cold water lines. At this time during your homes construction, he will also install tubs and shower pans, with the exception of marble tubs or other custom tubs which you may be installing at a later date. This is only true for tubs and shower pans which are flanged in with the sheetrock. At this time in your homes construction he also stubs out for all plumbing fixtures and drains. Your plumbing contractor should be responsible for supplying the roofing contractor with flashing for the vents, and is also responsible for any that are not flashed (in the event he doesn’t have enough flashing to supply the roofer, or the roofer neglects to install them all. Also at this time, he should have the sewer line completed to the main, and the water supply hooked up, with all ditches backfilled and culverts installed. Be sure that he cleans the job site and sweeps off the slab at the time he is finished with the work. Payment for plumbing top-out is made only after the above items (including sewer tap) are complete.