by jason_cramp | June 24, 2021 1:42 pm
With the surge in demand for all things pool and backyard living, consumers are actively looking to create an at-home vacation experience with water features on pools providing beauty and fun for the entire family. To create custom water features with the appearance of natural rock, glass-fibreglass-reinforced concrete (GFRC) panels have quickly become popular for pool builders who want flexibility and ease of installation. Whether it is enclosing a slide, building a grotto cave and water feature, or simply adding a small waterfall or fire feature, GFRC panels and rocks provide a lightweight, yet extremely strong system allowing pool builders to create beautiful and fun custom water and fire features around the pool.
As pool builders embark on putting together a GFRC rock feature on a pool, one of the best places to start is with the slide. When it comes to making pools fun, slides are by far one of the most popular accessories—especially for pools being used by children. However, slides tend to stand out from the overall design of the pool, so GFRC panels can be a clever way to integrate these accessories into the deck and coping. They are also an excellent starting point from which to create a custom rock design on a pool.
Shaun Lambert of Lambert Custom Pools in Springfield, Ill. is a big fan of using GFRC panels to create custom enclosed slides and water features on the pools his company installs.
“We know filling in around and behind a slide with rock gives the pool a much more integrated look,” says Lambert. “We like using GFRC panels and boulders because they are very realistic-looking, and the product is easy to work with.”
Lambert says he has enclosed and integrated many slides on pools, most of which also have an adjacent grotto, cave, or other water feature.
“We always show customers photos of our GFRC work and those homeowners that can afford it, want their pool to look like the photos we show them,” he says.
Once a rough design is agreed upon, builders work with the manufacturer to determine what to order.
“We start with a rough design that allows us to determine how many and what size GFRC panels and rocks to order, but we also do a lot of ‘design on the fly’ once everything is laid out on the job site,” explains Lambert. “You definitely need to have a designer’s eye on site to put all the pieces together to make them look like one big rock.
“The factory offers design help as we tell them the size of the slide and elevation and they will help us determine what it will take to enclose the area below the slide. They will also design a rock staircase that will lead up to the top of the slide, using a combination of boulders and GFRC panels,” says Lambert. “We email back and forth with the designers so they can help ensure we get the correct tread heights and widths going up the slide so everything lines up.”
Just in case, Lambert generally orders a few extra panels and boulders in addition to everything he thinks he will need for the job.
“Because there is customization involved, you don’t want to be stuck waiting for an extra panel on the job you didn’t anticipate,” he says. “It’s best to order more and save any extra materials for use on a future job.”
Covering up slides tends to be a starting point around which many pool builders create more expansive custom water feature designs. By using the slide enclosure with a faux-rock staircase as a starting point, it becomes easy to add a water feature, grotto, or jump rock. Water features and boulders on either side of the slide can give a pool great visual appeal and more entertainment options. This also creates spaces where pool builders can add fire and lighting features to the custom rock structure.
Selecting the type of GFRC ‘stone’ is also an important part of the design process. It might be obvious at first but selecting the right stone for the landscape helps ensure the finished project is cohesive in its design. There are GFRC panels and rocks designed to look like granite, limestone, or fractured stone. Pool professionals should look to select stones like those found in their region of the country.
“You want the style of the stone to look like it comes from your area,” says Lambert. “Here, in Illinois, I’m not going to pick a fractured stone look you would find in a place like Wyoming because it will look out of place.”
[3]There are tricks to ensure success with GFRC panels. To begin, pool builders must use a lathe similarly to brick layers. The lathe is used to bridge the gap between the boulders and panels; drill a hole on each side of the panel, then run a zip tie through the hole onto the lathe. The lathe keeps the concrete and mortar from falling off by giving the concrete mortar mix something solid to adhere to.
There are a few ways in which builders provide support to the GFRC panels during the installation process. Some builders bolt them to a concrete support panel as they connect each GFRC panel, while others use what is called a post-and-beam installation, where cinder block walls are built in behind to hold the panels in place.
This is particularly important when working with slides because builders should try to avoid connecting the fibreglass slide and GFRC panels—especially in freeze/thaw regions.
“As a result of these severe temperature changes, the fibreglass slide can move through expansion and contraction so you don’t want the slide or the stone to expand and break,” says Lambert. “We design the rock and fibreglass so they don’t touch and, therefore, move independently to avoid cracking. Although they need to be free of each other, we work hard to make it appear as though the slide is fully integrated into the rock.”
There are also some best practices builders should follow when it comes to the mortar techniques used with GFRC panels. Concrete castings can be quite dense and do not absorb water so they must be set with a rich mortar mix. Most masonry supply businesses have a ‘better quality’ mortar mix or cement, which can be blended with masonry sand and tends to work best. Mortar should be easy to trowel into place—not too runny or stiff. It should also be left to set to avoid smearing fresh mortar.
After it has hardened, the mortar can be cut and brushed away; a slight undercut will provide a nicer finish. Some installers use antiquing to age the joint after the mortar is dry, while others use rainbow cement so the mortar dries the same colour as the castings. It is important to remember temperatures should be above 4.4 C (40 F) to ensure the mortaring process is successful.
There is a certain amount of artisan work involved in building with GFRC panels and boulders. Not only is there artistry in the cutting, sizing, and placement of the panels and rocks, but also in the staining and colouring of the materials.
When it comes to sizing GFRC panels, cutting them with a concrete saw is not ideal as there is more potential for error and these saws can not only produce a large amount of harmful dust, but also can quickly make a job site filthy. Once the panel is measured, it is best to use a chalk line to mark where the panel should be cut, then builders should use a hammer drill to make small holes along the chalk line. Next, a mall sledgehammer should be used to tap along the holes to break the panel gently along the chalk line.
In addition to cutting and placing the panels, creativity is needed in the staining process to achieve the desired look. To create a natural looking GFRC panel and boulder, many layers of staining and colour must be applied over multiple days. It is important builders take time to do the staining in stages. In doing so, one should stand back and look at the entire project at different times of the day. The goal is to stain the panels with shadows to mimic the look of real rock. In addition to the panels, all the boulders must be stained to match. After applying the base coat, builders can start adding highlights and shading. The colouring process can take three to four days to replicate the shadowing effect of real rock. This is where the artistry comes in.
“You don’t want to over-do it,” says Lambert. “It is a gradual process. We also like to invite the client to come stand with us and look at the water feature to get their feedback on the staining and colouring as we find the client likes to be involved in the design process and helps ensure the final success of the job.”
Adding fire and lighting to GFRC rock is easier than adding fire and light to real rocks. Fire features are popular and can be built into the GFRC using either natural gas or propane. Builders simply need to run a gas line on the inside of the GFRC panels, which is much easier than working with real rock.
“Most of the time, we place a stainless steel fire feature on the GFRC rock and fill it with either glass or lava rocks, and it creates a nice ambiance,” says Lambert. “That said, fire features should not be placed too close to the slide, slide staircase, or near areas where users might walk.
“You need to be sure it’s not too close to the flume so when kids come down the slide with their arms stretched out, they can’t get hurt.”
Some builders, including Lambert, have created stand-alone pillars using GFRC panels and rocks, upon which fire features can be placed to create stunning backyard ambiance.
In some cases, it is much easier to install landscape lighting on GFRC rock and, like landscaping lighting, it makes the rock features pop.
“Most of the time, we use light-emitting diode (LED) lighting and set it up so the homeowner can use a wireless remote to control the colours and timing,” says Lambert. “We also put lighting on the slide staircase so users can see where they are going in the dark.”
Pools builders looking for ways to create unique designs for both new and existing pools should consider using GFRC panels and rocks. Some builders prefer to use water feature kits which are easy to install and provide a predicable finished look, while others are attracted to the customization options of using GFRC panels and rocks. In either case, the use of GFRC allows builders to create unique one-of-a-kind water features that can lead to referrals and keep installation crews busy year after year.
[6]Bruce Riley is the managing director of RicoRock Inc., makers of cast-concrete rock, including component systems for building caves/grottos, waterfalls, and waterslide products for use in pool applications. Riley focuses on developing new products and managing commercial installations. He has built rock-type pools in southern California for more than 25 years and now uses this experience to design standard waterfall kits for the company. He can be reached via email at bruce@ricorock.com[7].
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