Vertical Sewers & Storm Risers.

Class A VA Contractor License #2705147099
DMBE VA SWAM # 684641

Vertical Sewers & Storm Risers

What is a vertical sewer or storm piping?

Vertical sewer or storm pipelines, often called risers or "drainage, waste, and vent pipe," (DWV) run vertically from the rooftop of a building all the way down to the ground surface level or sub surface basement level. The drainage risers are tied into fixtures such as sinks, showers, and bathtubs and carry clean water down to the horizontal underground lines. Storm risers drain pooling rain water from roofs, decks, and patios. Waste risers are connected to toilets and urinals and are responsible for carrying the emission from these fixtures. Ventilation is delivered throughout the system by the vent pipe risers, which carry air instead of liquid. A horizontal pipe cross connects with the vertical piping at each flooring level to drain the corresponding waste effluent from those fixtures into the vertical riser. While the vertical riser generally runs in an up and down fashion, it is also very common for one to make multiple bends and turns as it makes its way through a building. It can be typical for a vertical riser pipe to transition in diameter as it collects more drainage piping on its way down to grade level. Conventional DWV’S range from 2"- 8" in diameter. Vertical piping is usually made from Cast Iron, Ductile Iron, Copper, or PVC.

What happens over time to vertical piping?

Much like other building or facility assets, vertical piping ages and the material becomes thinner and rougher overtime. Metallic based vertical piping such as cast iron, which is the most common vertical pipe material, can be vulnerable to surface corrosion from years of chemical and detergent use. As chemical corrosion matures the pipe surface thins and begins to form linear and longitudinal cracks. During the corrosion process the pipe walls become increasingly rough. Surface roughness allows fat, oils and grease deposits to attach to the pipe walls which constricts the vertical piping’s flow capacity. Vertical pipe problems can cause: surface and wall damage, mold or mildew, water service disruptions, excessive internal flooding, personal property damage, and emergency restoration expenses.

What is Dynamic Drain Technologies process for lining vertical piping?

At Dynamic Drain Technologies, we use a design first philosophy. Due to the complex nature of vertical piping it is vital that we understand and observe all construction, operational, and structural details of a buildings vertical plumbing system. The design process starts with a site survey in which all plumbing and drain fixtures are accounted for. Our team of specialists then tag and title the access points. These access points provide entry to the vertical piping system. Access is vital and must be considered when moving forward into the video inspection and pipe cleaning phases.

Pipe inspection and location.

Pipe inspections allow us to do several very important things. First and foremost, they allow us to locate and map the piping system. We can see the plumbing and drain fixtures but we need to understand how and where they intersect to our vertical pipeline. We trace the piping system via a sonde transmitter located in our camera heads. We often place painters tape on the wall surface to mark the location and vertical path of the riser piping. Digital site plans are also generated during this process. Pipe inspections also allow us to gather and observe conditional data points of the slab piping system. This data consists of structural, operational, and maintenance related observations that determine the proper methods and levels of pipe cleaning and preparation needed to install a cured in place vertical pipe liner.


At this point we have all the information needed to present the data and layout the action or pipe lining design. Design will cover the following areas: scope of works, approximate pricing, working hours, project durations, pipe cleaning, diversion or bypass pumping options, water shutdown, CIPP liner design calculations, and finally project management requirements and responsibilities.

Pipe Cleaning

The pipe cleaning process requires a remarkable amount of labor and technical expertise. A typical vertical pipe cleaning scenario may call for heavy amounts of mechanical chain knocking or scouring of the internal pipe surface. This process removes years of rust deposits from the pipe walls and surfaces. The dislodged debris are then washed out with forced air or high pressure water jetting. The desired result of this process is to achieve a clean pipe surface, free of any deposits or roughness that could interfere or interrupt the bonding of the cured in place pipe liner.

Cured in Place Pipe Lining of Vertical Piping.

Once the pipe is completely cleaned, technicians then perform another video pipe inspection to record the pipeline before the pipe liner is installed. This is done to show that the pipe was properly prepped and cleaned prior to installing the liner. All lining materials are fabricated onsite using our turnkey job-ready mobile trailer units. Our mobile lining trailers are outfitted with state-of-the-art electric vacuum assisted wet out tables. The liner material is loaded onto the roller table and the epoxy resin is introduced to the liner and passed through the electric roller until the liner has reached 100 percent saturation.

Now the liner is ready to be loaded into one of our inversion devices and inverted into the pipeline using compressed air. This process is called inversion. For single access installations, a bladder or calibration tube is inserted after the liner and inflated to press the liner against the pipe walls. Once inversion is complete a curing method is implemented. Depending on the application the liner can be cured using 2 methods. The most time-consuming method is an ambient cure. During an ambient cure epoxy resins are combined with an accelerator that will encourage a natural air cure within 3-4 hours of installation. Faster cure times can be achieved by using external heat sources. The quickest external heat source is steam. Forced steam is passed through the liner until the epoxy reaches its desired exothermic flash point. Depending on the diameter and length, using steam can reduce cure times to 1-2 hours.

After a proper cure time is reached, air pressure can be released and the calibration tube can be removed. At this point the liner is now fully cured and bonded to existing pipe walls. A post liner video inspection is then conducted verifying the quality of the install. Then, especially in a vertical pipe environment, it will be necessary to reestablish or reinstate the cross connecting service pipes that our liner has covered. This is done by placing a robotic and pneumatic driven cutter into the pipe liner and grinding out the liner that has covered the connections while monitoring with a video inspection camera. After all connections, have been reestablished, the pipe liner is then flushed again with high pressure water to remove all debris from the reinstatement process. A final pipe inspection video is produced to show the newly installed and reinstated vertical piping.

At the finale of our process we have achieved an internal pipe repair without the need of and demolition. This pipe liner will have 50-year design life and will improve flow capacity by as much as 75%. Vertical pipe lining is one of the most cost effective pipe repair options a multi-story facility will encounter. Downtime can be limited by using this trenchless technology.