Condominium and apartment pipe lining in Denver, Colorado

What is being lined in a multi-unit building

Condominium and apartment pipe lining in Denver, Colorado is a different project from a single-family lateral, even though the liner is the same. A mid-rise building has vertical waste stacks, one per column of kitchens or bathrooms, each collecting short horizontal branch lines from every unit it passes. The stacks drop to a horizontal building drain under the lowest slab or hung in the garage ceiling, which runs to the sewer lateral and the street. In older buildings all of it is cast iron; stacks and building drain corrode from inside while the branches fail at the fittings. A lining scope has to say which of these three systems it covers, because each is accessed and priced differently and disrupts a different set of residents.

What the board or property manager needs before a proposal

A complete camera survey coded to NASSCO PACP is the starting document, not a proposal. It should cover every stack from the roof vent or top cleanout to the building drain, the building drain to the lateral, and a representative sample of branches, with each unit's connection logged by floor. That survey shows which risers are failing and which are sound, which is what lets a project be phased rather than done all at once. A survey covering only the building drain, because it is easy to reach, leaves the stacks that actually cause the leaks unassessed.

Phasing by riser

The unit of work in an apartment building is the riser: one stack and the branches feeding it. Lining a riser means those units lose drain service for the cleaning, lining and cure, so scheduling is organized around one riser at a time, and the sequence starts with the worst-coded stack. Within a riser the day runs as follows.

• Isolate. Residents on that riser are told not to run water for the posted window.
• Descale and clean. Cast iron stacks are chain-flailed from the top and jetted; the debris comes out at the base cleanout. A second camera run confirms the wall.
• Line the stack. A liner is inverted or pulled from the roof or top cleanout down through the stack and into the base fitting, then cured with hot water or steam.
• Reinstate the branches. Every unit connection is now covered by the liner. A robotic cutter travels the stack with a camera and opens each one to full size at the logged depth.
• Line the branches. Where the survey showed the branches failing, short liners are installed from the fixture side or from the stack, and the fixtures are reconnected.
• Verify and release. The post-lining video is recorded, each opening is flow tested, and the riser is returned to service.

An account of condominium and apartment pipe lining in Denver shows what the cutter does at each connection, the step residents ask about most because it decides whether their sink drains the next morning.

Resident notifications and water-off windows

The water-off window is the whole resident experience. Notice should go out in writing well ahead, name the riser and the affected unit numbers, give the hours and state clearly what cannot be used: every drain on that riser, not just the ones that look damaged. A reminder the day before and a knock on the morning of the work catch those who did not read the first one. The window should be realistic. A cast iron stack that needs heavy descaling and a hot-water cure can occupy a riser for a full working day, and a building in Denver with occupied units on every floor needs that stated honestly rather than as a hopeful half day. Portable facilities on the ground floor, a posted contact for the day and a plan for a resident with a medical need at home are the details that keep a board from fielding complaints.

Who owns which pipe

In a condominium the governing documents usually make the stacks and building drain common elements and the branches either limited common elements or unit-owner property, and the split determines who approves and who pays. The board can authorize lining the stacks; it may need owner consent to line the branch inside a unit, and needs owner cooperation for access. In a rental building the owner controls everything and the constraint is tenant notice under the lease and Colorado landlord-tenant law, which the property manager should confirm rather than assume. A lining contractor that works regularly in multi-unit buildings around Denver should be able to describe how it sequenced access and consent on a comparable job.

Documentation the board should keep

The project file becomes part of the building's permanent record, asked for by future boards, buyers, lenders and insurers. It should contain the PACP-coded pre-lining survey, the post-lining video for every riser with each reinstated connection shown open, the liner and resin data sheets with the ASTM F1216 or F1743 basis, the cure logs, a riser diagram marking what was lined and what was deferred, the permit and inspection sign-off where Denver requires one, the manufacturer material warranty and the installation warranty with the installer's license number. Boards comparing proposals for how branch connections are reinstated after lining should score the documentation offered as carefully as the price; a riser lined without a record will be surveyed again in a few years to find out what was done. When the shortlist is set, verified CIPP installers serving Denver is where a board can confirm the crew's certification and its recent multi-unit work before the first notice goes under a door.

Common questions in Denver