In-building pipe rehabilitation: Convenient and cost-effective repair method

by arslan_ahmed | June 8, 2023 3:06 pm

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By Ryan Graham

The average commercial building in the U.S. is approximately 53 years old,¹ and considering the average performance lifespan of a building plumbing system is approximately 30 years, there are thousands of commercial buildings with pipes suffering from age-related build-up and blockage, rust, cracks, and leaks. Without question, the risk of failure in plumbing systems is high.

For these reasons, pipes in older commercial buildings—ranging from apartments, assisted living centers and hospitals to office buildings, resorts, and casinos—need repairs, replacement, or rehabilitation. Traditionally, total pipe replacement involves removing all old pipes and replacing them with new ones. This requires contractors to cut and remove the drywall, flooring, fixtures, and finishes to reach the plumbing systems. This type of demo can also potentially expose lead and asbestos, which are harmful human carcinogens. Even dust created from this type of work can contaminate living spaces and cause health issues for tenants. The abatement cost of these materials, if found or uncovered, is extremely high. Depending on the building, tenants, guests, staff, and patients are unable to occupy those spaces and must be relocated for several days, weeks, or even months while the demolition, pipe replacement, and renovation takes place.

A better plumbing repair alternative

In-building pipe rehabilitation can be an attractive alternative to traditional plumbing repair methods, given the exorbitant cost, mess, time, investment, and disruption of a total pipe replacement. Modern in-building pipe rehabilitation offers complete restoration of vertical and horizontal plumbing systems located within walls and under floors, without the need for pipe replacement and the costly, invasive demo and repairs associated with it. This non-invasive form of pipe repair is ideal for vent, stack, and branch lines, and horizontal sewer pipes up to 304 mm (12 in.) in diameter, allowing buildings to remain open and occupied during the repair process.

In-building pipe rehabilitation is not new. In fact, for the last 20 years, it has proven to be more efficient, cost-effective, and less invasive than traditional commercial building plumbing repairs and replacement methods.

 

The process for an in-building pipe rehabilitation project

Preparation for this process starts with shutting off the water to the area being worked on and then gaining access to each stack line from the top floor. A temporary bypass system, involving the horizontal main sewer pipe located in the building’s basement, is installed to allow the crew to flush, clean, and repair the pipes. The bypass is then removed at the end of each day to restore full service to the entire building. This process is repeated each day as the crew moves through the building, restoring the pipes. Debris and blockage caused from years of build-up inside the pipes is then removed and cleaned using precision, high-speed drain cleaning tools to prepare the pipes for relining.

There are several non-invasive in-building pipe repair options which are significantly less expensive than total replacement costs. The most common methods of in-building pipe rehabilitation are brushed-in-place-pipe (BIPP) and cured-in-place-pipe (CIPP) processes. Ultimately, the diameter and condition of the pipes determine which method is used.

The BIPP process

The BIPP process requires specialty equipment to apply a 100 percent solids epoxy onto the interior walls of the pipe. Since epoxies are both highly corrosion- and abrasion-resistant, the relined pipe will function as new for many years. This method is particularly effective in leaking smaller diameter 31.75 to 203.2 mm (1.25 to 8 in.) drain and branch lines found in traditional plumbing. It can also be used to reline potable water mains, using NSF-61 certified, 100 percent solids epoxy.

The CIPP process

The CIPP lining process consists of a felt or fiberglass liner, pre-impregnated with epoxy resin that is inverted into the pipe. For a commercial building’s stack and vent lines, this is typically performed from the roof, all the way down into the basement. The CIPP liner is then cured; and depending on the system, it is cured either using water and steam or ultraviolet (UV) light. Once the liner is cured, the branch line connections from each floor are reinstated using a lateral reinstatement robot that cuts through the liner and seals
the connection.

Whether they be for sanitary sewer or drinking water applications. The products must show proof of meeting minimum ASTM standards, as well as NSF-61 drinking water safety standards.

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No health inspectors are required, and any warranties for the product outside of a typical one-year performance warranty some manufacturers offer on their products is usually negotiated by the contractor as part of the bidding process. Most of these lines that are being rehabilitated for in-building rehabilitation are sanitary lines, which is the focus of this article. All warranties are negotiated as part of the deal. It could be two years, three years, or whatever is dictated by the bid documents and the requirements of the job in the specifications.

Once the vertical stacks are restored, the individual branch and drain lines are addressed by employing the same methods. Although service may be temporarily interrupted during the repair, access to the pipes is typically through drains or exposed pipe joints, minimizing any damage or removal of sheet rock or flooring. After the main and branch pipes are rehabilitated, the connections between them can then be sealed using similar CIPP or BIPP methods.

Examples using in-building pipe rehabilitation

A total pipe replacement compared to a non-invasive in-building pipe rehabilitation project immediately demonstrates the advantages of the latter process. A Washington State retirement community with three multi-story buildings underwent a total pipe replacement. The cost to relocate the community’s residents during the pipe replacement exceeded one million dollars. In contrast, when the retirement community owner needed to perform similar services at one of their other properties, they sought a more affordable solution and chose the in-building pipe rehab process. The non-invasive procedure allowed residents to remain in their units, saving the owner the expense of temporary relocation, demolition, and reconstruction. In addition, the project was completed in roughly half the time of the total pipe replacement.

It is common for a variety of materials to be required for in-building rehabilitation projects. Sourcing materials from multiple vendors can take time and extend a project’s duration and cost as well.

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For an Oregon retirement community with 10 floors, 18 stacks, and more than 762 linear m (2,500 linear ft) of deteriorating cast iron pipes, in-building pipe rehabilitation was the ideal choice—as it avoided disrupting and relocating the community’s 150 elderly residents. This project required multiple materials, however, they worked with a company that provided trenchless and non-invasive in-building pipe relining solutions; and this eliminated sourcing delays and allowed the expansive undertaking to be completed in just five months, while residents remained in their units. It is important to note this project only
had one crew, consisting of four to five workers. By adding more crews, completion time can be significantly reduced.

Conclusion

Traditional total pipe replacement requires more labor, time, and materials than in-building pipe rehabilitation. It also incurs more costs, as excavation damage to drywall, flooring, and more must be repaired, forcing inconveniences such as relocation or business disruption due to the inability to access water. This is where in-building pipe rehabilitation demonstrates a clear advantage.

Innovative materials and equipment to promote the advancement of non-invasive commercial plumbing supports the commercial plumbing community. Whether the plumbing repair involves main lines, laterals, branch lines, verticals, sectional repairs, cold weather, or environmentally sensitive areas, these systems are designed to stop leaks, improve flow, prevent corrosion, and restore structural integrity. The final result can extend the life of the existing pipe and plumbing system by up to 25 years. In-building pipe rehabilitation enables commercial facilities to remain open while providing durable, reliable pipe repair. As in-building pipe systems in high-rise and multi-story buildings age, this modern trenchless pipe repair approach represents an optimal, cost-effective option that benefits facility stakeholders, occupants, and building managers alike.

Notes

¹ Refer to the report, Research Commentary by Stuart A. Feldstein, president, SMR Research Corportation. To read the report, visit www.commbuildings.com/ResearchComm.html#:~:text=Age%20of%20U.S.%20Commercial%20Buildings,slight%20increase%20over%20prior%20years[4].

Author

Ryan Graham is senior vice-president, services for Vortex Companies; a provider of trenchless and non-invasive pipe relining solutions. He has more than a decade of trenchless infrastructure rehabilitation and water/wastewater industry experience. Graham has progressed in increasing roles of responsibility since joining Vortex at its inception in 2015.

Source URL: https://www.constructionspecifier.com/in-building-pipe-rehabilitation-convenient-and-cost-effective-repair-method/

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