# Does repiping include drain pipes? > Does a repipe include drain pipes? How supply, drain-waste-vent and sewer piping differ, what a Columbus repipe quote covers, and when stacks get replaced too. URL: https://slaterepipingcolumbus.com/guide/does-repiping-include-drain-pipes/ Learn A house has three separate piping systems. A repipe replaces one of them. Here is how to tell them apart, read where a quote stops, and decide whether an old cast iron stack should come out while the walls are open. Last Updated: October 29, 2026 Learn A house has three separate piping systems. A repipe replaces one of them. Here is how to tell them apart, read where a quote stops, and decide whether an old cast iron stack should come out while the walls are open. Last Updated: October 29, 2026 No. A repipe replaces the water supply piping: the hot and cold lines that carry pressurized drinking water from the main shutoff to every fixture. Drain, waste and vent piping, which carries used water out of the house, is a separate system, and the sewer line outside is a third. [Slate Repiping Columbus](https://slaterepipingcolumbus.com/) offers and manages [whole-house repiping](https://slaterepipingcolumbus.com/whole-house-repiping/) in Columbus and nearby Franklin County communities and, as a separate service, [cast iron stack replacement](https://slaterepipingcolumbus.com/cast-iron-stack-replacement/) for older drain stacks. This guide explains how the systems differ and when it makes sense to do both. Key takeaways - Repiping replaces the hot and cold water supply pipe, not the drains or the sewer line. - Drain, waste and vent piping works by gravity and is a separate system with separate pipe. - The sewer lateral outside the foundation is a third system and a separate job. - A cast iron stack can be replaced alongside a repipe when the same walls are open. - A quote should say plainly which systems it covers. ## Three systems in one house ### Water supply The supply system starts where the buried service line comes into the house, in most Columbus homes through the basement wall near the inside meter. From the main shutoff a main line runs to the water heater and splits into hot and cold, with branches to each sink, toilet, tub, shower, appliance and hose bibb. The pipe is small, half an inch to an inch on most branches, and it is under pressure all the time, so a leak sprays or drips whether or not anything is running. Older Columbus houses have galvanized steel or copper here; new work is PEX or copper. This is the system a repipe replaces. ### Drain, waste and vent The drain, waste and vent system, often shortened to DWV, carries used water away. It is not under pressure; it works by gravity, so every horizontal drain slopes downward. Each fixture drains through a trap that holds a little water to keep sewer gas out, into a branch, and from there into the stack: the wide vertical pipe that runs from the basement to the roof. The top of the stack is the vent, which lets air in so drains flow and lets gas out above the roof. At the bottom, the stack turns into the building drain, which leaves the house through the foundation. In houses from the early twentieth century, the stack and building drain are usually cast iron, sometimes with galvanized steel for smaller drain and vent branches. ### Sewer lateral Outside the foundation, the building drain becomes the sewer lateral, a buried pipe that runs to the public sewer in the street or alley. Its ownership, materials and repair methods belong to a different trade and a different set of rules, and it is not part of a repipe or a stack replacement. ## Why the two inside systems get confused Supply and drain pipes sit side by side in the same walls, especially in a bathroom wet wall, and both can be old metal in an older house. A leak from either shows up as a stain on the ceiling below. A homeowner who hears “the pipes are bad” may not know which system was meant, and a quote that just says “replace plumbing” does not say either. The quick way to tell them apart is size and direction. A supply pipe is narrow and can run up, down or sideways. A drain pipe is wider, always slopes down, and the stack is the largest pipe in the house, usually three or four inches across. The [guide to identifying pipe material](https://slaterepipingcolumbus.com/guide/how-to-identify-pipe-material/) covers what each metal looks like. ## What a repipe quote should cover A clear whole-house repipe quote describes the supply system only, and it should say so. It lists the new pipe from the main shutoff to each fixture, the material, the valves, the fixture reconnections, the pressure test, the permit and every wall or ceiling opening with who closes it. The [Columbus repipe cost guide](https://slaterepipingcolumbus.com/guide/repiping-cost/) shows what typically sits inside that price. What a repipe quote normally does not cover: - Drain lines, traps and the stack - Vent piping through the roof - The building drain and the sewer lateral - The buried water service line from the curb to the meter, which is [water line replacement](https://slaterepipingcolumbus.com/water-line-replacement/) If a quote is unclear, ask which of these it includes. A quote that is cheaper because it leaves something out is not the same scope as one that includes it. ## When the stack gets replaced too A cast iron stack does not have to be replaced just because the supply pipe beside it is. Plenty of old stacks are still sound. But a repipe is a good time to look, because the walls the stack runs through are often the same walls opened for the new supply lines. Signs that the stack is worth replacing while the walls are open: - Rust stains, weeping or a visible crack on the stack, especially at hubs and fittings - Slow drains on upper floors that keep coming back after the traps are cleaned - A sewer smell that persists after traps, toilet seals and vents have been checked - Old repairs with rubber couplings or patches in more than one place None of these proves the stack has failed; a slow drain can be a clogged trap, and a smell can be a dry floor drain. A look at the stack and, where it matters, a camera inspection settle it. If it is replaced, the [cast iron stack replacement](https://slaterepipingcolumbus.com/cast-iron-stack-replacement/) page covers the choice of PVC, ABS or new cast iron, the temporary support while it is cut, and the testing before walls close. Doing both together means one schedule, one round of openings and one round of patching. It also means two kinds of work under the plumbing permit, so the scope should list both. The [guide to how invasive repiping is](https://slaterepipingcolumbus.com/guide/how-invasive-is-repiping/) covers what the openings look like in practice. ## Older Columbus houses The houses most likely to have both old supply pipe and original cast iron stacks are the oldest ones. Census figures put 12.0% of Columbus homes as built in 1939 or earlier, but more than half in the 43206 ZIP around German Village and the 43205 ZIP around Olde Towne East. [Old house repiping](https://slaterepipingcolumbus.com/old-house-repiping/) covers the particular problems of those houses, and anyone [buying a house with old pipes](https://slaterepipingcolumbus.com/guide/buying-house-with-old-pipes/) can ask the inspector to note the supply pipe, the stack and the sewer lateral separately, since each is priced as its own job. ## The short answer for a quote When comparing quotes, line them up by system: water supply, drain and vent, sewer lateral, service line. A repipe quote covers the first. A stack replacement covers part of the second. The last two are separate jobs. Getting that clear before work starts avoids the most common surprise after a repipe: finding out the old drains were never part of it. The [repiping guide](https://slaterepipingcolumbus.com/guide/repiping-guide/) covers the full process from first symptom to final inspection. ## Questions about this guide ### How can I tell a supply pipe from a drain pipe in my basement? By size and direction. Supply pipes are small, usually half to one inch, run in any direction and are under pressure. Drain pipes are wider, slope steadily downward toward the floor or the building drain, and the vertical stack is the widest pipe in the house. ### Is the sewer line ever part of a repipe? No. The sewer lateral is the buried pipe that carries waste from the foundation to the public sewer. It is outside the house, it works by gravity, and it is repaired or replaced as its own job, separate from both the water supply and the drain stack inside. ### Why didn't my repipe quote mention the drains? Because a repipe is a water supply job. A clear quote says it replaces the hot and cold water piping from the main shutoff to the fixtures. If drain or vent work is wanted, it should be listed as a separate line with its own scope and permit details. ## Related service ### Whole-house repiping Every hot and cold supply line from the main shutoff to the fixtures, replaced in PEX or copper, pressure tested and inspected under a City or suburban plumbing permit. ## More guides - Learn [How does repiping a house work?](https://slaterepipingcolumbus.com/guide/repiping-guide/)The whole picture in one place: what the water supply system is, why galvanized and older copper give out, how a repipe is scoped, permitted, installed and tested in Columbus, and what to ask before agreeing to one. - Cost Guide [How much does it cost to repipe a house in Columbus?](https://slaterepipingcolumbus.com/guide/repiping-cost/)Typical Columbus-area ranges for a whole-house repipe in PEX or copper, what sits inside the price, the permit fees by office, and why two quotes for the same house can differ. - Learn [How invasive is repiping a house?](https://slaterepipingcolumbus.com/guide/how-invasive-is-repiping/)Where the openings go and why, how plaster and drywall differ, how dust is kept in one room, what to clear out beforehand, and the scope question that decides who closes every hole. - Learn [How do you identify lead pipes and other pipe materials?](https://slaterepipingcolumbus.com/guide/how-to-identify-pipe-material/)A refrigerator magnet, a coin and a flashlight answer most of the question. This guide shows what each pipe looks like, how to check safely, where Columbus's map helps, and what each material means for the house. - Decision Guide [Should you buy a house with galvanized pipes?](https://slaterepipingcolumbus.com/guide/buying-house-with-old-pipes/)Old pipe is a known cost once it is scoped, not a reason to panic. What the inspection note does and doesn't tell you, how to look up the service line on the City's map, polybutylene, and how to negotiate with a real number before closing.