Renovation Solutions for Indoor Pools
By Steve Comstock
Renovating commercial aquatic facilities on a tight schedule is nothing new to our construction crews. However, renovating three indoor high school aquatic facilities in a single summer was challenging.
This was exactly the situation when we were awarded the contract to renovate three Houston swimming pools at Clear Brook, Clear Creek and Clear Lake High Schools. The $1.4 million pool construction contract was initiated because of safety regulation compliance, but each pool was showing its age. The pool at the Clear Creek campus was about 38 years old while the pool at the Clear Lake campus was estimated to be about 32 years old. The youngest of the pools was the Clear Brook pool, which was only about 20 years old. The pools were suffering from leaking pipes and gutters to cracked and peeling pool surfaces as well as serious structural issues.
All three of these pools were suffering from the same issues in varying degrees. Each pool was a typical, competitive high school pool with racing lanes. Each pool was 49 feet wide by 75 feet long, and 3.5 feet deep in the shallow end. All pools had to be reconfigured to a 12-foot 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 repainted for many years.
The school district had a limited budget and, therefore, chose to use a PVC membrane (or pool shell) to remedy the cracks, chipping and peeling pool surfaces in all three pools. All three pools were also experiencing varying degrees or leaking in the recirculation systems, gutters and piping. Some of this leaking also caused structural damage to pool walls and floors that required rebuilding of some of the pool structures.
The first step in the renovation was rebuilding the pool structure. The process started with replacing the main drains and related plumbing, the drains needed to comply with the Virginia Graeme Baker Pool & Spa Safety Act. As a result, sections of the floor were also opened up to expose the current drain system. One pool had been leaking over the course of many years so a good portion of the structure was damaged. This meant that the entire back end wall and floor needed to be restructured and reinforced with a new stainless steel wall structure. For structural reasons, the finished wall had to be completely self-supporting before installing the PVC membrane. Pool structure repairs were concurrent with the renovation of the plumbing and the replacement of the exiting trenches so the new perimeter gutters could be installed to restore the water recirculation system.
The water recirculation systems of all three pools were badly deteriorated. The walls of the trenches were caving in, and the plumbing had been compromised because of ground-shifting. The pools had inadequate filtration for the water flow in addition to having an old-style "trench gutter" that was difficult to maintain because of the deterioration. The next step of the renovation was to rebuild the perimeter recirculation system, gutters, grating and the decks on each pool.
Because the trenches were in such poor shape, water had been seeping under the pool deck, causing many areas of the pool to crack and sag. As a result, replacing the existing troughs was necessary. The old gutter and wall top had to be cut out to install a new, custom-built stainless steel gutter with 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 the inner trough wall form the return piping making it virtually maintenance-free while eliminating an often fragile perimeter piping system. The stainless steel gutter is welded into place and connected to all the pipes. This gutter replacement took about two to three weeks for each pool. The plumbing was also repaired, all the plumbing lines were tested and the walls back-filled before the new pool deck was fixed. After all this was done, the three pools were ready for the PVC membrane installation.
The 60-mil, reinforced PVC liner was chosen as the solution for these three concrete pools because it provides a cost-effective, watertight fix that is attractive and relatively fast to install. Putting in a PVC membrane immediately "cleans up" the look of the pool and often makes it safer as well, with contrasting colors used on racing lanes and transitions from shallow to deep areas of the pool. In addition, the PVC membrane is 60mil thick and reinforced, making it nearly tear-resistant. The membrane is also flexible making it able to expand and contract with any future ground shifting while still retaining a watertight seal.
One of the initial complaints by operators of these older pools had to do with pool water maintenance. In addition to repainting and patching the pool surfaces, the facility managers were also having a difficult time with water chemistry. It appears that the plaster surface of the pools was suffering from calcium leaching out of the substrate, especially as the surface became rougher over the years. These rough pool surfaces allow more dirt to collect, which means that more chemicals are required to keep the water clean and clear. A PVC membrane liner actually makes the pool water chemistry easier to maintain and, in fact, will decrease the amount of chemicals needed to maintain water chemistry. This is another operational cost savings benefit to aquatic facilities that install PVC membranes.
In the case of these three pools, in addition to the base blue material of the membrane, we also had to weld on the racing lanes, targets, safety line and other pool markings in a black PVC material. This material is placed on top of the first blue layer of PVC membrane and takes precise skill to ensure proper location and sizes during installation.
The PVC membrane installation for each of these pools took an average of 10 to 14 days per pool. Once the membranes were in place, we were now in the final stretch of putting on the final touches on the pool, just two weeks before school opened.
It was now late August and the three pool renovations were moving along, on schedule, when the entire city was forced to evacuate to designated shelters as high winds and torrential rains from Hurricane Gustav came sweeping into town. Because of the tight, indoor space limitations of these pools, much of our equipment and supplies were stored outside of the building when the hurricane hit the area. Unfortunately, after the winds subsided, we went looking for our supplies—some of which we found a quarter mile away from the high schools, and some of the materials were actually lost. Luckily, we had not encountered any other delays in our renovation plan, so the hurricane did not affect our promised completion date.
All three pools were completed before school opened again for the fall. The visual results were remarkable. In addition, the aquatic facility managers reported to us that these pools with the PVC liner were now easier to clean and they noticed that the water chemistry balance was also easier to maintain and control.