Renovating three high-school pools in one summer

by jason_cramp | October 18, 2016 2:21 pm

By Steve Comstock

[1]

Renovating commercial aquatic facilities on a tight schedule is not uncommon for most construction crews in the pool industry; however, renovating three high school pools (managed by the same school district) over the course of one summer is a challenging feat. Adding to the difficulty of the project was the fact all of the pools were older, indoor facilities, where space is tight and access is limited.

This was the situation RenoSys Corporation faced when it was awarded the contract to renovate three Houston, Texas, pools at Clear Brook, Clear Creek and Clear Lake high schools. The $1.4-million pool construction contract was initiated due to non-compliance with safety regulations. Each pool was also showing its age and required much-needed rehabilitation. The pool at Clear Creek was approximately 38 years old, while the pool at Clear Lake was estimated to be about 32 years old. The pool at Clear Brook was roughly 20 years old.

That said, managing three crews simultaneously over the course of a hot summer in confined interior spaces was a major undertaking.

The problems

[2]

All three pools—in varying degrees—were suffering from the same problems. Each competitive aquatic facility was 15 m wide by 23 m long (49 ft wide by 75 ft long), and 1.06 m (3.5 ft) deep in the shallow end. At one point, one of the pools was re-configured to a 3.65 m (12 ft) depth in the deep end to comply with diving code requirements. All of the pools were showing wear-and-tear with chipping and flaking surfaces as a result of being patched and re-painted for many years, leaving them rough and unsightly.

The school district had a limited budget to complete the three pool renovations and, therefore, chose to use a polyvinyl chloride (PVC) liner (or membrane) to remedy the cracks, chipping, and peeling surfaces in all three pools.

Further, the recirculation systems, gutters, and plumbing on all three pools were also leaking in various degrees. Some of this insidious leaking had also caused structural damage to the pool walls and floors which made it necessary to rebuild some of the pool structures.

Pool structure rebuilding

The first step in the renovation process was rebuilding the pool structures. Renosys started this process by replacing the main drains and related plumbing, which needed to comply with the Virginia Graeme Baker Pool & Spa Safety Act (P&SS Act). As a result of this, sections of each pool floor were opened up to expose the current drain system. In addition, two pools had to be made deeper to comply with the current codes for diving board use.

One pool was leaking over the course of many years and, as a result, a good portion of the structure was damaged. This meant the entire back wall and floor needed to be reconstructed and reinforced with a new stainless-steel wall structure.

The reinforced, stainless-steel wall used 1.2-m (4-ft) centre buttresses along with horizontal supports that were 305 to 457.2 mm (12 to 18 in.) on centre. For structural reasons, the finished wall had to be completely self-supporting before the perimeter gutter system and the PVC membrane could be installed.

[3]

The lining system enabled the crew to rebuild each pool in sections (where necessary) and with various types of construction material so the structure could be repaired as they knew the liner would span all cracks and cover all patches and rough surfaces to not only provide a watertight seal, but also a clean, attractive, finished surface.

Repairing the pool structures were completed concurrently with the renovation of the plumbing and the replacement of the existing trenches so the new perimeter gutters could be installed to restore the water recirculation system.

Gutters and water recirculation system renovations

The water recirculation systems on all three pools were badly deteriorated. The trenches were collapsing and the plumbing lines were compromised due to ground shifting. The pools had inadequate filtration for water flow along with an old-style ‘trench-gutter’ that was difficult to maintain due to their deterioration.

[4]

The next step of the renovations was to start with the rebuilding of the perimeter recirculation system, gutters, grating, and decks on each pool. Due to the trenches being in such poor shape, water was seeping under the pool decks causing many areas of the pools to crack and sag in various degrees. Therefore, to replace the existing troughs on each pool was necessary. The old gutter and wall top had to be cut out to install new, custom-built stainless steel gutters. These gutters included a turn down flange to which the PVC liner would be attached.

The perimeter gutter is equipped with a return/supply system that continuously overflows the dirty water over the handhold. The gutter face and inner trough wall form the return line making the system virtually maintenance-free while also eliminating the fragile perimeter plumbing system. The stainless-steel gutter is welded in place and connected to all plumbing lines. It took approximately two to three weeks to complete this work on each pool.

All of the plumbing lines were tested and the walls were backfilled before the pool deck was repaired. Once all of this was completed, the pools were ready for the liner installation.

Prepping the pool surface

The 60-mil reinforced liner was selected for these concrete pools because it provides a cost-effective, watertight fix that is attractive and relatively fast to install. Installing a PVC membrane immediately cleans up the look of a pool, while the use of contrasting colours for racing lanes and transitions from shallow to deep areas can also make them safer.

The surface patches on these pools were not only an eyesore, but were also signs of underlying issues with the pool structure caused by leaking plumbing. Further, the thickness of the reinforced PVC membrane makes it nearly tear-resistant and capable of withstanding heavy use. The membrane is also flexible; therefore, it can expand and contract with any future ground shifting while still maintaining a watertight seal.

[5]

One of the initial complaints by the facility managers of these pools was regarding water maintenance. In addition to repainting and patching the pool surfaces, they were also having a difficult time with water chemistry. The plaster surface of the pools appeared to be suffering from calcium leaching out of the substrate, especially as the surface became rougher over the years. The rough surfaces also allowed more dirt to collect in the pools which meant more chemicals were required to keep the water clean and clear.

It is important to understand before a PVC membrane can be installed, several steps must take place first to prep the pool to ensure the long-term success of the liner. To start, a series of PVC strips need to be fastened along the perimeter under the stainless steel gutter, which is attached to the turndown flange. Next, the pool’s surface is prepared by smoothening rough spots, patching divots, and bridging gaps using an acrylonitrile butadiene styrene (ABS) thermoplastic polymer plate. Then, the walls and floors are washed with an algaecide to prevent any algae growth behind the PVC membrane.

Once the surface has been treated, a layer of adhesive is applied to the pool’s perimeter walls and floor to adhere a felt lining. The felt acts as a barrier to smoothen any remaining rough surfaces within the old pool. Even though the PVC membrane is a reflective material, the felt liner covers any surface imperfections and ensures the liner material has a smooth appearance—it also provides a cushioned feel for bathers. The felt lining is attached to the substrate using a solvent-based contact adhesive to ensure a strong, permanent bond.

Lining the pool surface

After applying the felt on each of these projects, the 2.05- x 25-m (6- ft 9- in. x 82-ft) PVC rolls were brought in. In many cases, these rolls had to be manoeuvred through standard-sized doorways and brought into the pool area one by one using hand trucks, rather than by the pallet.

[6]

The PVC membrane was then rolled out and positioned within the pools. The material is essentially tailored to the pool on-site. Once the pieces were measured, cut, and positioned, a tack weld or pre-weld was used to hold it in place. Using a heat gun, each seam is heat welded on-site by melting them together. In doing this, the PVC seams should overlap approximately 51 to 76.2 mm (2 to 3 in.). The membrane that comes up the pool wall is ultimately terminated by welding it directly to the PVC band, or attaching it mechanically, which was the case for these three projects.

To add another waterproofing measure, a sealer was applied along the seam edges to ensure water would not seep into the scrim of the material over time. This procedure also rounds out the seams and adds an extra layer of waterproofing to the liner at critical areas.

In the case of these three pools, in addition to the base blue material, the racing lanes, targets, safety line, and other pool markings also had to be welded on using a black PVC material. This material is placed on top of the first PVC membrane layer (blue) using precise skill to ensure proper location and sizes during installation.

The PVC membrane installation took approximately 10 to 14 days to complete for each pool. Once the liners were in place, the pools were near completion—just two weeks prior to the first day of school. In late August, with each pool renovation on schedule, the entire city was evacuated to designated shelters as a result of high winds and torrential rains from Hurricane Gustav.

Due to the space limitations at these indoor pools, a lot of the equipment and supplies were stored outside of each school when the hurricane hit the area. After the winds subsided, some of the equipment and supplies were found 0.4 km (.25 miles) away from the high schools, and some of the materials were actually lost. Luckily, no other delays were encountered during the renovations, and despite the hurricane, all three pools were completed on schedule.

The results

In addition to the night-and-day change of each pool’s visual esthetics, the aquatic facility managers also reported they were easier to clean and maintaining and controlling the water balance became less complicated.

[7]Steve Comstock is the executive vice-president at RenoSys Corporation, a company specializing in commercial pool renovations based in Indianapolis, Ind. He has worked in the commercial aquatics industry for more than 36 years and has helped renovate thousands of commercial pools across Canada and the U.S. Comstock can be reached via e-mail at stevec@renosys.com[8].

Source URL: https://www.poolspamarketing.com/trade/renovating-three-high-school-pools-in-one-summer/

---