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When Should Plumbing Risers be Replaced?

Written by Michael Tobias | 9/7/17 1:00 PM

Plumbing risers are embedded in building walls, and as a result they can be one of the most challenging building components to upgrade. However, they deteriorate with time and reach a point where they can no longer deliver water effectively, making an upgrade necessary. This is especially true when dealing with the galvanized steel risers found in older buildings.

Although it may be difficult to justify a plumbing riser upgrade from the financial standpoint, there are cases where assuming the consequences of doing nothing is more expensive! In addition, a large-scale plumbing upgrade provides a great chance to improve other building elements such as water heaters and plumbing fixtures.

When Should Plumbing Risers be Replaced?

If a building is experiencing widespread water supply issues, it may be time to replace the plumbing installation. If the following issues are present in your building, a plumbing riser upgrade may be the solution:

  • Insufficient water pressure: Galvanized steel risers accumulate scale and rust on their interiors surfaces over time, and this gradually reduces their ability to carry water. In upper floors, the water delivered by faucets and showers may be reduced to a trickle.
  • Colored water: If plumbing fixtures are delivering brownish water, it is a warning sign that piping has accumulated large amounts of rust and scale. These compounds can be harmful for health if they contaminate kitchenware and are consumed accidentally.
  • Excessively hot showerhead water: Modern boilers can generally adjust their heat output according to water flow, which means they can deliver hot water at constant temperature. However, older boilers typically have a fixed heat output, which means water is delivered at a higher temperature when flow rate is reduced. This can be an issue when clogged plumbing risers reduce flow, since water may be delivered to showerheads at a very high temperature, exposing tenants to burns.
  • Water leaks: Rust reduces pipe diameter over time, eventually causing leaks. Consider that the piping has become thin and brittle by the time when this happens, which means there is a higher risk of sudden failure, potentially leaving many tenants without water.

In short, a piping upgrade is necessary if the existing installation is no longer able to deliver enough water, or if quality has become unacceptable due to rust contamination. Partial upgrades are not recommended because they result in contact between new and old piping, which accelerates corrosion due to the materials difference; old piping normally uses galvanized steel, while new installations use copper, brass or stainless steel.

Key Responsibilities and Considerations for a Plumbing Upgrade

If a major plumbing upgrade is required in a residential co-op building, the responsibility is generally split between the property management company and the tenants. In general, the property management company will be responsible for the service entrance and risers, while individual branch line upgrades are paid by tenants. In commercial buildings owned by a single company, cost allocation is not an issue, but a similar approach to that of co-op buildings may be followed if there are many tenants leasing commercial spaces.

Regardless of occupancy type, it is important to contact a NYC Licensed Master Plumber (LMP) before proceeding with a plumbing riser upgrade. Minor projects such as faucet and showerhead replacements can be carried out without major hurdles, but NYC laws only allow an LMP to carry out major projects. Hiring an LMP for the job also saves plenty of time on paperwork, which can be very confusing and time-consuming for someone unfamiliar with NYC procedures. A major plumbing project should never be attempted without an LMP, since the building owner risks causing property damage and may also be subject to hefty fines by the NYC government.

Even if performed superbly and without errors, a plumbing riser upgrade is always a disruptive project, where it is necessary to open walls for rough in. In older buildings there is also a risk of disturbing asbestos, and removal can only be performed by qualified asbestos remediators. There is also a chance of disturbing lead-based paint that has peeled off over time, which also represents a health hazard.

Recommended Procedure During a Plumbing Upgrade

Old plumbing risers and branch lines may have become unsuitable for handling after decades of corrosion, especially because rust makes steel piping brittle. Therefore, the recommended procedure is to install the new piping parallel to the existing one, and then switch over the water supply and fixture connections. Projects where a direct upgrade is attempted are hindered by the following issues:

  • Old plumbing systems may lack valves to isolate sections of piping, which means it may be necessary to leave the entire building without water while performing plumbing work.
  • Scale and rust inside piping is disturbed, with means the water supplied to tenants will be even more contaminated for the duration of the project.
  • Brittle piping may break when handled by the plumbing contractor, which has the potential to leave many tenants without water for several days. There is also a risk of spilling large amounts of water, which may cause moisture damage or mold growth in the affected area.

In other words, trying to replace the existing piping brings no advantages, and installing new plumbing risers and branch lines from zero is much easier. It is true that some sections of the existing piping may still be in working condition, but reusing them involves contact among different metals and also speeds up corrosion. Stainless steel and galvanized steel pipes can normally be in contact without major corrosion issues, but this only applies if both pipes are new, which is not the case in plumbing upgrade projects.

Recommended Complementary Upgrades

Upgrading the plumbing risers in a building involves opening walls and floors, and it represents a great chance to improve other systems.

  • Since new piping will be laid out for the entire building, it is a great chance to connect modern water heating systems, such as heat pumps or tankless heaters.
  • Plumbing fixtures can also be upgraded to fixtures with the WaterSense label from the US Environmental Protection Agency, which deliver water savings of 20% or more compared with standard products. The savings go even higher when WaterSense fixtures are compared with the leaky faucets, toilets and showerheads found in old buildings. Consider that water savings also result in heating savings, for the simple reason that less water is flowing through the boilers.

If a large-scale plumbing upgrade is complemented with water heating and fixture upgrades, there can be a significant reduction in operating costs, which means building owners can gradually recover the cost of the upgrade.