Consulting MEP Engineers
The windows of certain key units were replaced to allow a
pathway for horizontal plumbing piping, through a new one foot
section of the wall.
Openings were scanned and core drilled to provide pathways
for new drainage piping.
The ProVent combined waste and vent systems were designed
and installed.  These fittings combined with PVC pipe are
assembled to create a single stack combined waste and vent
system.  The PVC ProVent risers have flexible joints to allow for
thermal expansion and building movement.
On the intermediate floors the storm drainage and single waste
and vent stacks continue down the building.
At the top floor, roof drain lines offset into the unit to connect
to the existing roof drains.  Also the waste and vent stacks
continue up through the roof.
Wall enclosures are framed out to enclose piping, protecting
them from sun  and weather and containing noise.

A UNIQUE PLUMBING REPLACEMENT PROJECT in Honolulu is being currently installed, and will be
completed over a span of several years.  It is not a typical "One for One" replacement project which
other buildings in Honolulu have done.  This project features new combined waste and vent
drainage stacks in a different location, at the exterior balcony, which allows this system to coexist
with the existing waste and vent stacks.  There are advantages in budgeting, scheduling, and
convenience with this design alternative.  The entire drainage system will also be constructed of
PVC in lieu of cast iron, which will not corrode over time.

The new waste and vent system will be entirely built out of PVC pipe and fittings.  The key to this
design is PVC fitting, manufactured by ProVent, located in Lawrenceville Georgia.   The durable
combined waste and fitting will not rust, but will allow use of a single stack, similar to its cast iron
cousin, Sovent.  These special waste and vent fittings will become an integral component of the
plumbing drainage design.

Kapiolani  Bel-Aire is a mixed use condominium project in the Kapiolani area and is over 50 years
old.  It has 18 floors, with 12 floors of residential apartment units above commercial units and
parking levels.  The plumbing drainage piping is in need of replacement.  Numerous leaks in the
cast iron waste and vent piping have occurred in the past, and the replacement of plumbing
drainage systems is a priority.  

A local mechanical engineering firm, NOTKIN  HAWAII INC. has designed the replacement plumbing
system at Kapiolani Bel-Aire .  Phase 1, which consists of the installation of the combined waste and
vent stacks, of the project is scheduled to complete in the first quarter of 2022.  Phase 2 will begin
as soon as Phase 1 is completed, and is planned to progress over several years.  
                                                                 Advantages include:

:  The combined waste and vent single pipe stack is less cost than a conventional waste and
vent stack, as each drainage stack requires one penetration instead of two.

Budgeting:  The phased nature of the stack allows flexibility to fund this project over the course of
several years, compared to a conventional project which would complete in about six months and
require either a construction loan or special assessment.

Scheduling:  The new project has virtually no waste stack downtime. The work is spread over
several years.  A conventional replacement project will typically require daily shutdown of the
plumbing system while the work is in progress.  

Convenience:  In a conventional one for one plumbing drainage replacement project, where work is
attempted on an occupied building, the active sewer system is temporarily opened up during each
work day, then closed back up at night.  The occupants can come back to their unit at night,
although often when might not have all plumbing fixtures usable.  Thus, during construction, there
is always a risk of sewage flowing and causing damage when the old stacks are removed and
replacement piping  is in the process of being installed.  

Typically during one for one replacement, water to the stacks or even to the building (if the water
stack shutoff valves don't function) must be shut down daily, during work hours, to lessen the risk
of accidental use of plumbing fixtures when the system is disassembled.  Then water is turned back
on in the evening.  This is a tremendous inconvenience for residents.

However, the proposed project has none of those inconveniences.  With the proposed combined
exterior stack, since each apartment unit will have access to a new stack to replace their existing
plumbing drainage lines.  Other units in the building are generally not affected.  Downtime is
reduced.   Each apartment can theoretically schedule their work separately from other units.

Longevity:  The new PVC system should last the remaining life of the building.  However, a new cast iron
drainage system will typically require replacement after 30 years.  Thus, as soon as other buildings
have completed their plumbing drainage project they will need to reserve funds for a replacement.  
However, a PVC system which will not corrode should last at least 2-3 times longer than cast iron.
Walls are constructed to match the building.