Transforming a vinyl pool into a custom concrete design

by Sally Bouorm | April 1, 2010 2:33 pm

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By Brian Worley

Every year, builders are presented with many options when summoned to a homeowner’s backyard. In some cases, the homeowner knows exactly what they want; in others, builders are looked upon to create the backyard of the customer’s dreams simply by using their own imagination and expertise.

Sometimes a slight twist presents itself in the form of old pool renovations. Some builders will not take on these projects, largely because they do not know exactly what they are getting into. Others look at these types of projects as the ultimate ‘before and after’ opportunity. A builder/designer can use these projects as a way to showcase his diversity. It is one thing to have a fresh palette and build something out of nothing, but to change an ‘eyesore’ into a beautiful project—like the one described in this article—is an art form in itself.

More than just a liner replacement

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For years consumers have asked us to change out their liner and try to give the pool a facelift of some kind. We had always done this with much success, but without much of a ‘splash.’ As a builder, I like to think when we leave a job we leave our ‘pool DNA’ behind in the form of original ideas and concepts. This way of thinking left me looking at liner replacement/renovation projects in a different light.

Recently, a client called us to look at the possibilities of renovating his 30-year-old, freeform vinyl-liner pool. The backyard had a natural setting, however, the pool stood out like a sore thumb.

The first problem: the cantilever concrete coping was deteriorating and needed to be replaced. We explained to the homeowners the pool liner would also need to be replaced, as the existing liner track was damaged and the extent of the renovation would require us to be in the pool to achieve what was needed with the coping. (The liner was about 10 years old and was due for replacement.)

As we went through all the options, the homeowner asked if it was possible to change the pool to concrete, so we put together a plan based on the several vinyl-to-shotcrete renovation projects we had already done.

Au naturel

Working with the backyard’s natural surroundings, we decided to go ‘all natural’ with the renovation. Instead of a tiled border and symmetrical coping, which takes away from the natural feel of a pool, shotcrete was used on the coping and pool shell. Then, the concrete was carved to create the look of fractured rock.

This is not a consistent shoot, as it is intended to look as though the rock goes up and down the side of the pool, sometimes even protruding all the way to the pool floor. This creates the effect of a rock that had to be left pushing into the pool from outside the shell during the original build.

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To create this look, we first had to remove the old liner and pool coping along with the steel steps at the end of the pool. As the pool had no bottom drain, and circulation was not being optimized; this had to be addressed.

The homeowners wanted the original pool’s pressure-side cleaner removed, which provided us with a plumbing line to install a Virginia Graeme Baker Act (VGBA)-compliant channel drain in the pool floor. We then added a light to the shallow end of the pool in what would become a bench and tanning shelf.

Steel was then installed to provide strength for the shotcrete application. The original pool walls were also left in place, as they were still very strong and provided a form for the shotcrete, which also allowed for a consistent shell depth. In this case, the deck and coping were left in place to become part of the new pool.

Gravel was placed in the void created by the removal of the pool steps and a steel cage was built to create the tanning shelf and benches. A new light niche was also added to the pool’s deep end to replace the original niche, due to deterioration and the need to accommodate the new shell.

The shoot begins

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As usual, concrete was placed starting with the walls. However, because this was an existing pool with close proximity to the house and a finished stone wall, we did not add air to the shotcrete process. Mixing air with shotcrete is a messy process; in this case, a cleaner application was required. The existing floor of the original pool allowed us to use a 51-mm (2-in.) line pump to ‘stack’ the shotcrete without the need for air.

With the proper mix, this works well. Given the relatively shallow depth of the pool, there were no problems. Lathe, a strong wire-mesh material, was also attached to the existing steel walls, which allowed the new material to adhere properly to the original surface during shotcrete application.

As shotcrete placement begins to cover all the walls, we started to add more material to the coping area. A ‘carver’ then began to shape the shotcrete as it was built outward, beyond the walls. This is how the natural rock look was achieved. Texture pads and a release agent were also used on top of the coping to give it a natural effect. The benches were then finished and the floor poured.

Personnel is very important during this process. The coping has to be worked quickly enough to achieve the required look; otherwise, a secondary material like mortar has to be used to finish out the coping. When used in moderation, this is not necessarily a bad thing; however, too much can make the coping too heavy, which will have an effect on the long-term life of the pool’s finish. When the shoot was finished, a concrete pool-shell protector was applied to the entire shell and coping. This protects the concrete from deterioration and provides maximum efflorescence control.

Touch ups

Once the shell is complete, the coping and skimmer boxes were touched up and coloured to give them a natural look, and gunite skimmers were installed in place of the old vinyl liner skimmers. An aggregate surface was then applied to the pool shell, which comes right up to the bottom of the ‘rock’ coping inside the pool, just as it would tie into a tile-finish in a regular pool surface application. When completed, the water line lies on the coping, giving the pool a very natural look.

Additional features

In this particular project, the homeowner also wanted a natural rock waterfall flowing in to the pool. This feature was built using real boulders in addition to carved shotcrete, while a return line from the original pool supplied the water. The waterfall is built to tie into the coping, as if it were an original part of the setting.

Originally, the deck was finished in an outdated pea-gravel cement. Due to the deck’s size, as well as the difficult location of the pool, we decided to resurface the deck instead of removing it and starting anew. The concrete was surprisingly sturdy after 30 years, which allowed us to keep it intact.

We removed all of the original wood expansion joints and repaired several cracks with polymer filler. The joints were expanded to 229 mm (9 in.) and pavers were installed to add a more rustic look.

A polymer spray deck was then applied. In this application the material was sprayed on the deck with a hopper gun and then ‘knocked down’ to achieve the desired look. A colour sealer was then applied to the finished surface.

The end result gave the homeowner what appears to be a completely new pool, while minimizing the construction process. Old pool structures are not always as stable as this one, so it is imperative to investigate the existing pool before moving forward. In some cases, we will extract the original wall system and begin with a new shell entirely. This is a much more extensive project, but may be necessary at times.

A custom fire pit was also added, in what was originally a planter bed in the pool deck. We simply stacked and carved concrete around a block structure in the same fashion as the pool coping. Gas logs and a burner tray were then fitted for installation. A hot tub could easily be built the same way to add to the ambiance.

Our goal for this project was to create an atmosphere that appears as if there was a large rock in this area and we simply carved a ‘pond’ out of it. Decking options can certainly naturalize the setting greatly. In this project, however, we were limited somewhat by budget and proximity to reasonable logistics.

Thinking outside the box

The absence of heavy machinery makes for a much neater construction process overall, something not associated with most swimming pool projects. This is just one possibility for a pool renovation, which shows how ‘thinking outside the box’ can open many doors.

 

Brian Worley is the owner and president of Everclear Pool and Spa Company Inc., in Chattanooga, Tenn., a builder of custom concrete pools and spas. He can be reached at brianworley@comcast.net[5].

Source URL: https://www.poolspamarketing.com/trade/transforming-a-vinyl-pool-into-a-custom-concrete-design/

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