The Earl Mah Aquatic Centre: Renovating a 36-year old whirlpool

June 12, 2019

By Michael Rusz

The Earl Mah Aquatic Centre commissioned Berndorf Bäderbau, a European stainless steel pool installer, to renovate the facility’s 36-year old whirlpool with a stainless steel design. [1]
The Earl Mah Aquatic Centre commissioned Berndorf Bäderbau, a European stainless steel pool installer, to renovate the facility’s 36-year old whirlpool with a stainless steel design.

As an aquatic facility owner or operator whose pool has seen better days, one may reflect on how many people enjoyed the pool, whether relaxing after a busy day at work or simply trying to get into shape with a regular aquatic workout. At the time, when the installation was new, one’s primary concern was to ensure bathers enjoyed their experience and returned on a regular basis.

Over the years, however, new concerns may have started to arise: regular, expensive maintenance requirements, cleaning hazardous mould, repairing loose tiles with sharp edges, re-grouting, resurfacing, repairing cracks, fixing leaks, etc. Suddenly, the pool that once brought immense joy presents itself as a money-draining pit. As a facility owner, one finds themselves with three options:

  1. Renovate the existing pool;
  2. Demolish the pool and build a new one from the foundation; or
  3. Build a new pool on top of the existing one.

For the Earl Mah Aquatic Centre in Prince Rupert, B.C., the third option was the most feasible. After more than
36 years of regular use, the whirlpool at the facility required renovation as the leaks were beyond repair. The centre commissioned Berndorf Bäderbau, a European stainless steel pool installer that has completed more than 8000 pool projects (with each consisting up to five pools), across the globe, for the job.

Originally opened on March 6, 1982, the facility is dedicated to Earl Mah, a lifetime member of the community of Prince Rupert. The first Chinese-Canadian born in Prince Rupert, he was a well-respected volunteer, businessman, and city alderman.

Why stainless steel?

Stainless steel can be used to build a pool of any shape and size, from small projects like cooling plunge pools, residential and hotel pools, and whirlpools to large aquatic centres and public pool complexes.

Note: Pools with skimmers or overflow gutters can be used for fresh or saltwater, ocean water, and even for water from the Dead Sea. However, for these types of pools, titanium is used instead of stainless steel.

Project planning and design

The Earl Mah aquatic facility includes an indoor pool complete with a diving area, a tot pool, a fitness centre, swimming lanes, saunas, and a whirlpool.

The 18-m2 (194-sf) wide skimmer whirlpool, with a volume of 10,834 L (2862 gal), was located in the middle of the building. It was built of concrete and finished with tiles. The current pool technology room is located behind the back wall of the pool.

The original idea was to demolish the existing pool and build a new one in its place. However, since the entire facility is built on piles with a crawlspace under the pools, the idea was quickly abandoned for two reasons:

  1. After the demolition of the original pool, it would be necessary to re-pour the base plate and supporting walls, which would significantly increase the cost of building preparation; and
  2. A void would be created in the middle of the lower floor, which could endanger the structure of the building itself.
earl mah aquatic centre. The 18-m2 (194-sf) wide skimmer whirlpool, with a volume of 10,834 L (2862 gal), was located in the middle of the building. It was built of concrete and finished with tiles. The current pool technology room is located behind the back wall of the pool.[2]
The 18-m2 (194-sf) wide skimmer whirlpool, with a volume of 10,834 L (2862 gal), was located in the middle of the building. It was built of concrete and finished with tiles. The current pool technology room is located behind the back wall of the pool.

It was, therefore, necessary to keep the pool in its original condition and build a new pool inside the existing one. The architect suggested building a stainless pool. The main priority for investors was maintaining the original structure with minimal intervention in its construction. The designers planned the appearance to match the original shape of the installation, including its staircase and shape of the benches.

A visually attractive overflow gutter was planned in the initial proposal, which would improve hygiene and eliminate the need to periodically rinse exposed parts of the pool.

However, it was difficult to find space for a surge tank in the existing building and, therefore, the option with a skimmer was chosen.

In order to design a new stainless steel pool and maintain the original concrete structure, it was necessary to narrow the design by nearly 170 mm (6.7 in.) from each side, with the pool area now sitting about 400 mm (15.7 in.) above the floor.

The number of hydro-massage jets was increased from 10 to 26. Two 70-m3/h (2472-cf/h) air bubblers were added to the floor as part of the multi-purpose floor jet (combination of inlet, drain, and bubbler). An air massage feature was designed in the bench for every seat. Among other features was a 1.25-m (4.10-ft) long suction channel for attractions, a second drain in the stairs, a flood valve, two multi-purpose floor jets, two skimmers, and four red, green, blue (RGB) lights.

The contractors ensured all the equipment met the province’s pool code requirements for safety against blocking and hair entrapment and simple cleaning and maintenance.

Challenging times ahead

earl mah aquatic centre. The designers planned the appearance to match the original shape of the installation, including its staircase and shape of the benches.[3]
The designers planned the appearance to match the original shape of the installation, including its staircase and shape of the benches.

The biggest challenge for the team was meeting the deadline for completing the installation. The client wanted the project to be completed by the start of fall 2018. Keeping these dates in mind, the design of the whirlpool, its approval, and manufacturing process was completed in two months, the transportation took four weeks, and another four weeks were reserved for the installation itself.

None of this would have been possible without a Canadian-European Union free trade agreement, which allows the European manufacturer to carry out the installation of stainless steel pools in Canada and to recognize and accept European public health and safety certificates. However, the pool equipment must comply with Canadian pool standards.

The stainless steel parts of the whirlpool were manufactured in Czech Republic and Austria and transported in a 12.2-m (40-ft) container from Hamburg, Germany, to Montreal, Que. The parts were then loaded in a train to be transported to Vancouver, B.C., and were finally delivered by a truck to Prince Rupert.

Once the truck arrived at the aquatic facility, the container was dropped by a crane and the pallets with pool parts were unloaded by a forklift. After unwrapping the protective, corrosion-resistant foil, the parts were safely transported on trolleys to the assigned area inside the building.

Even though the whirlpool was installed on top of the existing structure, the general contractor had to complete two building modifications before the installation. First, he cut out paving, measuring 102 mm (4 in.), around the perimeter of the pool so its walls could be anchored. Second, he demolished the space between the back of the pool and the technology room to create space for piping from the pool hydraulics.

During these construction adjustments, he found sewer pipes and a concrete wall under the original floor that was not in the architectural drawing. These obstacles were tackled during the welding process and were bypassed using 90-degree elbow pipe fittings.

Stage one: Perimeter walls and hydraulics installation

In order to design a new stainless steel pool and maintain the original concrete structure, it was necessary to narrow the design by nearly 170 mm (6.7 in.) from each side, with the pool area now sitting about 400 mm (15.7 in.) above the floor.[4]
In order to design a new stainless steel pool and maintain the original concrete structure, it was necessary to narrow the design by nearly 170 mm (6.7 in.) from each side, with the pool area now sitting about 400 mm (15.7 in.) above the floor.

Prefabricated pool parts have pre-included slots for RGB lights and skimmers, insulating sheets in walls, hydro massage jets, air massages in benches, and piping from the attractions. Similar to the whirlpool, all the equipment, including pipes, was made of 316-L (83.5-gal) stainless steel.

After installing and levelling each part, they were tack-welded with a neighbouring piece until the entire perimeter (with a wall tolerance of plus/minus 2 mm [0.07 in.]) was completed. The pool was then placed in its final position with the help of a lifting device. The supporting legs were anchored to the original base plate and the entire pool was properly welded.

After the perimeter, the installation of the hydraulic system located in the floor came into play. In addition to the skimmers, the hydraulic system consisted of two multi-purpose floor jets and two drains (one in the floor and another in the stairs, including a flood valve).

After completing the hydraulic installation, the pipeline was insulated with lightened polyethylene foam. The piping for attractions was terminated at the front of the mechanical room wall and the one from the hydraulics ended in the mechanical room.

Note: During welding, it is important to undergo a dye test wherein the weld is sprayed with a capillary and chalk is applied. This helps repair any potential cracks in the welds immediately.

It was important to ground the pool before it was handed over to the concreters. Since the stainless steel pool is tightly sealed after welding, it can be grounded, theoretically, to any part of the pool, most often to the supporting leg. In this case, grounding was carried out on the flange in the technology room so the route to the central switchboard was as short as possible.

Stage two: Concreting the Earl Mah Aquatic Centre

The pool was then covered with a protective foil, the hydraulics were concealed with plywood, and the space under the pool floor, including the anchored legs, and the pipeline were concreted (in case of larger pools, only the hydraulics and the support legs are set in concrete, the remaining space under the floor and behind the pool walls is backfilled with a coarse and fine gravel, excluding metallic parts).

Stage three: Floor installation, cleaning, and filling Earl Mah Aquatic Centre

Once the concrete had dried out, the floor plate with embossed 3D knobs (which created a slip-resistant surface also embossed on the entrance stairs) was placed on the surface. It was then welded to the perimeter and hydraulics.

Afterwards, it was brought to the forefront of the handrail, which was then hand-polished to a high mirror gloss. This enhanced the resistance of the material to chlorides.

Note: The surface of the pool is ground while the handrails are polished. Handrails are also made of higher grade stainless steel (duplex) because of its higher corrosion resistance against evaporating chlorides from the water.

At this point, the mechanical contractor connected the pipes from the existing mechanical equipment and the new air blower to the stainless steel pipeline.

The pipelines from the skimmer, inlet, and drain were connected in the pool technology room, whereas the water and airway piping were connected before the wall of the mechanical room. The control valves were also fitted and closed in a stainless steel cabinet. This would allow the operator direct access to control the attractions in the pool area.

The head restraints were installed and perimeter walls were anchored to the floor using a stainless steel L-profile, which was then coated with epoxy glue and tiled.

Once the pool parts were welded, the welds were pickled with a paste to protect the joints from corrosion, and then ironed so they could be cleaned and the shade of stainless steel was obtained. This was followed by a pool and pipe test.

Finally, the most important task was to clean the whirlpool and train staff in its maintenance. There is a significant difference in maintaining stainless steel compared to concrete. This is because stainless steel pools are not required to be painted regularly with any protective coating. Also, it is not necessary to repair cracks, tiles, or other parts, which pool operators are accustomed to.

Stainless steel pools should be drained once a year, washed with cleaning detergent, and flushed with tap water. In this case, the cleaning process took an hour.

Maintenance requirements are generally different when comparing skimmers to overflow pools. While the former should be monitored regularly to check for evaporated chlorine on exposed parts of the pool (so-called chlorine ‘maps’ simply need to be wiped with a wet towel), this is not necessary in the case of pools with overflow gutters because all its parts are constantly immersed in water. Due to this system, the maintenance costs and times are significantly reduced.

A new spin

The whirlpool was installed in three weeks—a week ahead of schedule—and with minimal challenges. All the team members were able to work together successfully and complete the project in a month’s time.

In the author’s opinion, the process of renovating a concrete pool is an exciting solution for any type of project, whether it is a small residential pool, a whirlpool, or a large waterpark designed for the public sector. An interesting example is the reconstruction of the Riviera outdoor swimming facility in Brno, Czech Republic, where the original concrete waterpark was completely rebuilt into stainless steel in just 10 months. With a total water area of 6840 m² (73,625 sf),
the Riviera Aquatic Centre is the world’s largest outdoor stainless steel aquatic facility.

At present, many pool operators believe stainless steel is a material of the future, which has led to a large number of public pool developments incorporating this technology.

In addition to a clean, luxurious design and a wide choice of water attractions, stainless steel offers advantages other materials cannot provide. Specifically, the material’s lifespan (the oldest stainless steel pool by Berndorf Bäderbau was built in 1966, which is still in operation), maintenance and construction costs, and hygiene make it a suitable choice for many pool professionals.

And as far as the technology is concerned, due to its varied advantages, one can be sure they will meet it time and again.

[5]Michael Rusz is the owner of Stainless Steel Pool & Spa, which is the exclusive partner of Berndorf Bäderbau in Canada. He has been in the stainless steel pool industry since 2016, and his field of activity is in public, commercial, and residential constructions and renovations. He can be reached via e-mail at info@stainless-pools.com.

Endnotes:
  1. [Image]: https://www.poolspamarketing.com/wp-content/uploads/2019/06/AF_IMG_4407.jpg
  2. [Image]: https://www.poolspamarketing.com/wp-content/uploads/2019/06/IMG_4089.jpg
  3. [Image]: https://www.poolspamarketing.com/wp-content/uploads/2019/06/IMG_4111.jpg
  4. [Image]: https://www.poolspamarketing.com/wp-content/uploads/2019/06/IMG_4219.jpg
  5. [Image]: https://www.poolspamarketing.com/wp-content/uploads/2019/06/Michael-RUSZ-1_1.jpg

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