It depends on which pipe stopped up. A blockage in a stack or drain that serves several units is a common element the association maintains. A blockage in a branch serving only your unit is usually yours. Sewer backup damage is often excluded from standard policies, so check for a backup endorsement.
Which pipe decides who clears the blockage?
The default split is simple. A.R.S. 33-1247(A) says that, except as the declaration provides, "the association is responsible for maintenance, repair and replacement of the common elements and each unit owner is responsible for maintenance, repair and replacement of the unit." A pipe that serves several units is a common element, and a pipe serving one unit is a question of where it sits. A.R.S. 33-1212(2) says that when a conduit or similar fixture "lies partially within and partially outside the designated boundaries of a unit, any portion serving only that unit is a limited common element allocated solely to that unit and any portion serving more than one unit or any portion of the common elements is a part of the common elements."
The plumbing code gives the pieces names that make this easier to read. The International Plumbing Code, as adopted in Phoenix, defines them this way:
- Stack: "A general term for any vertical line of soil, waste, vent or inside conductor piping that extends through not fewer than one story with or without offsets."
- Branch: "A drain serving two or more fixtures that discharges to another drain or to a stack."
- Building drain: "That part of the lowest piping of a drainage system that receives the discharge from soil, waste and other drainage pipes inside and that extends 30 inches (762 mm) in developed length of pipe beyond the exterior walls of the building and conveys the drainage to the building sewer."
- Building sewer: "That part of the drainage system that extends from the end of the building drain and conveys the discharge to a public sewer, private sewer, individual sewage disposal system or other point of disposal."
Mapped onto a condo building, the usual pattern looks like this:
| Where the blockage is | Who usually clears it | Why |
|---|---|---|
| Trap, fixture drain, or branch serving only your unit | You | Serves only your unit |
| Stack carrying several units' waste | Association | Serves more than one unit |
| Building drain or building sewer under the building or parking area | Association | Serves the whole building |
| City main under the street | The city | Public sewer |
Treat the table as where an argument usually ends. A declaration can draw the line elsewhere, and where your unit's boundary sits changes the middle of the picture. Phoenix's plumbing amendments (Ordinance G-7397) change the grease interceptor definitions in Chapter 2 but not these four, so they read the same in Phoenix as in the model code.
How can you tell whether it is your branch or the building line?
Two clues do most of the work. If only your fixtures are backing up, the blockage is probably in your branch. If neighbors are reporting the same thing, or the lowest unit in the building is taking the worst of it, the problem is in a shared stack or the building drain. Waste surfaces at the lowest opening it can find, which is why ground-floor units, tubs, and floor drains show it first. Our page on how to tell a main line clog from a single drain clog walks through the fixture tests.
A plumber confirms it by finding the nearest cleanout and running a camera. That video, with the footage position of the blockage, is the document that settles most arguments. Ask for the finding in writing, and ask the plumber to note which line the blockage sat in and whether it serves one unit or several.
Who pays for cleaning up the damage?
The line that was blocked matters again, but now insurance enters. Under A.R.S. 33-1253(A) the association has to carry "Property insurance on the common elements and, if required by the condominium documents, the units, insuring against all risks of direct physical loss commonly insured against." Whether sewage backup is part of that coverage depends on the policy. Many insurers treat it as a separate endorsement.
Triple-I says: "Sewer backups are not covered under a typical homeowners insurance policy, nor are they covered by flood insurance." It adds that this coverage "must be purchased either as a separate product or as an endorsement to a homeowners policy." A condo owner's HO-6 policy follows the same pattern, so a loss like this may be uninsured until you check for the endorsement.
If the association's policy responds, the owner must go through the association. Section 33-1253(E) says an owner "shall report the loss to the association and give the association ten business days to provide the unit owner with a written decision whether the association will be reporting a claim to the master policy." The statute also lets the association charge costs that benefit only some units to those units: A.R.S. 33-1255(C)(2) says "Any common expense or portion of a common expense benefitting fewer than all of the units shall be assessed exclusively against the units benefitted," unless the declaration provides otherwise. For a sewer line that serves a handful of units, that can matter.
What should you do first?
- 1Stop using water in the affected unit, and tell neighbors on the same stack to do the same until the cause is found. Running a washer upstairs can push more waste to the lowest unit.
- 2Call the association or manager right away, in writing, and give the date, time, and affected fixtures.
- 3Call a licensed plumber to find the blockage and write down which line it was in. Our sewer backup response checklist for multi-tenant buildings covers the property manager side.
- 4Photograph before cleanup, and keep the receipts. Sewage cleanup, drying, and any damaged materials belong in the claim. See how to file a water damage insurance claim.
- 5Read your own policy for a water or sewer backup endorsement. Does homeowners insurance cover sewer backup explains the usual wording.
Keep people and pets away from sewage while that happens. It is a health hazard, and cleanup of porous materials is not a do-it-yourself job.
What if the association and the owner disagree?
Look at the declaration's definition of a unit, its maintenance section, and its insurance section, and ask the association for its position in writing. The statutes above lead with "Except to the extent provided by the declaration," so the document you signed at closing often has the answer. Disputes over the amount go through insurers, negotiation, or an attorney. This page explains general Arizona rules and is not legal advice.
HQ clears and camera-inspects building drains and sewer lines, and we can tell you which line the blockage is in, so you know where to start the conversation. We are licensed and insured, with free estimates and upfront pricing.