Fiberglass Pools - Uncovering the Truth About Factory Installed Tile

Uncovering The Truth about Factory Installed Tile

There is nothing like a beautiful, dramatic tile line to really set your pool apart from its surroundings. Tile has been a mainstay in swimming pools around the world for over a century, but few ever reflect on why it is there in the first place. The simple reason: reduced maintenance, particularly as seen in concrete pool (shotcrete) applications.

This little known fact concerning the maintenance role of tile can be cause for some confusion, even within the swimming pool industry. So how does tile reduce maintenance? On a concrete pool, the tile is used to create a water line surface that is both nonporous and easy to clean. Body oils and lotions collect at the water’s surface and are responsible for the "scum line." When that scum line falls onto a porous surface, like plaster, it can be difficult or impossible to clean. Therefore, the tile is used to protect the pool surface from an undesirable stain and allows the surface to be cleaned easily.

What about fiberglass or even vinyl liner pools? Do they need tile? The answer is yes, but for different reasons. Many pool builders sell a fiberglass shell by using the example that tile is not required, because the pool surface is already nonporous (like a glazed tile). The argument is since the fiberglass surface is nonporous, one doesn’t need the tile. Well, the response to this assertion is both yes and no. If one considers that a vinyl liner surface is nonporous when compared to concrete, and yet, vinyl liner manufacturers think tile is so important that they put a picture of it on the liner! These liner manufacturers know that it certainly looks good to have a tile line, but there is a second maintenance function that many are unaware. Perimeter tile creates a busy pattern at the waterline, which breaks up any scum line present so it is not noticed. In other words, just because it is easy to clean, does not automatically mean you want to clean it every day! With tile, the swimming pool appears cleaner, because you really can’t notice any scum line at the surface. The pool tile pattern hides this until you are ready to clean it.

Digging in to the fiberglass pool tile myth…

One of the great myths about tiling a fiberglass pool is that it cannot be installed level. In this case level means, of course, the tile level with the water line. Water seeks its own level, so if a tile line is not straight, relative to the waterline, it can be detected by even the untrained eye. What exacerbates the problem is that a tile line will often have a horizontal grout line, or even a horizontal pattern, that will draw ones attention to any unleveled installation.

So, is there some mystical force that causes tile not to be level on a fiberglass pool? Have we discovered some new warp in the time-space continuum? Well, as exciting as this may sound, the answer is no. This perception has its truth in a much more basic explanation: the way the tile was installed. Let’s take a quick trip back to the introduction of fiberglass pool shells nearly 40 years ago. The fiberglass pool manufacturer’s marketing these products to homeowners and pool builders were excited by the ease of installation. After all, compared to a concrete pool, there is no steel to bend and cut, no concrete to trowel, no surface sealing. A fiberglass pool shell is a real time saver, cutting weeks off the construction process at the job site. Arguably, this simplicity was a real hit with many pool builders. The problem is that the message can be taken too far.

The concrete guys have it figured out...

In a concrete pool, the shell is created over a steel cage and its rough shape is formed using shotcrete. The tile is installed using a water or laser level at the top perimeter of the concrete shell. Because the concrete shell is sitting in its final destination, level installation of the pool tile is easy to achieve. When the pool is filled with water, the tile is a work of art. Putting tile on a concrete pool is a time consuming process. As with any tile job, it requires skill to get the thin set just right, to hang the tiles with the right spacing, and then to come back after the tile is set to finish the grout lines. This is not to say there aren’t sloppy builders out there who don’t take the time to put on the tile level, rather, it can be easily done with care. There is nothing about the process that interferes with installing the tile level on a concrete shell.

Now let’s talk about the early fiberglass pool manufacturers and their marketing efforts. The conversation probably went something like this:

Pool Guy: So I don’t have to do steel, or shoot the shell, or plaster?
Fiberglass Mfg: That’s right, our pools come to the jobsite ready to install.
Pool Guy: wow…so I dig the hole, do some plumbing and then I start filling it with water the same day?
Fiberglass Mfg: Yes, you are in and out of the backyard in just a few days.
Pool Guy: What about tile?
Fiberglass Mfg: You don’t need tile; our non-porous gel coat finish is easy to clean!
Pool Guy: No tile line? Who cares about cleaning…that would look terrible.
Fiberglass Mfg: (light bulb-ding!) We’ll put it on at the factory FOR YOU!
Pool Guy: Where do I sign up?

Ok, maybe it wasn’t exactly that way, but you get the picture. Factory installed tile is a convenience to the pool builder – nothing more. Within this convenience, there is a problem. Let’s examine a 16 ft x 40 ft fiberglass shell as an example, install tile at the factory, and see what difficulties might arise. Because the pool bottom is usually sloped and the coping is level, it is simply easier to work on the shell when it is sitting upside down on the level pool coping. The natural waterline can’t be used as a guide to level the tile because there isn’t any water in the pool. The pool shell itself is probably not sitting on the ground perfectly level, so a water level can’t be used either. The best (and only) reference point left is the top coping of the fiberglass shell and the tile is installed level to this coping.

Assuming the original pool coping is PERFECTLY level to begin with (it's probably not) one can expect that the pool tile could be +/- ¼ inches off during the installation process. This is the tolerance, +/- ¼, given in the NSPI Workmanship standards for the levelness of pool tile relative to the waterline. Right off the mark, the manufacturer uses up the acceptable workmanship standard at the factory, installing tile level. Now, this 16 ft x 40 ft fiberglass shell is transported to your backyard and set in the hole. A skilled swimming pool installer can, with care, set this fiberglass pool shell to between ¼ and ½ inches of level from the highest to lowest end. It won’t be perfect, but close enough. Most fiberglass pool manufacturers, along with the NSPI workmanship standards, require that the shell be no more than 1 inch out of level from the highest to lowest point. Any person installing the pool should be able to hold a 1 inch tolerance.

Now let’s add all of the errors together and see what the outcome is. In the worst case we will see:

Pool Coping Error	0	inch
Tile Install Error	½	inch
Pool Install Error	1	inch
Total Tile Error	1 ½	inches!

We just may have our first insight into why someone might have the impression that tile can’t be level on a fiberglass pool shell. Using the best case above will result in +/- ¼ inch and that is the MAXIMUM allowed according to NSPI workmanship standards. So at best, this method produces marginally acceptable results.

Pssst. . . Want to know the real reason why fiberglass tile is perceived as being non level? It’s in the installation, silly!!

A little effort goes a long way...

Here’s a great idea!!! What if we simply put the pool tile on at the jobsite? Unfortunately, this seems to be a really novel approach for many fiberglass pool installers. We still get all the ease of installation originally promised, but now we have a fiberglass shell sitting in the ground with water filled to the top. Let’s assume the pool is at the MAXIMUM out of level position of +/- 1 inch. This means that the difference in the distance from the top of the pool coping to the waterline is no more than 1 inch from the highest to lowest spot. Now, it’s time to tile the pool at the jobsite. The first step is to pick a level line half way between the highest and lowest point on the pool. Next, the water is dropped to just below this level line. The waterline is then used to set the tile. Now we are actually using the tile to level the swimming pool: the exact approach shotcrete pool installers have been doing for years!

The number one reason to put on tile at the jobsite: You will get a much better looking tile job. Once the tile is placed level with the water line, the pool has the illusion of being level, even if the pool shell installation is off level. This is a trick concrete renovation specialists have been using for years when refurbishing an older pool or one that has been hydrostatically heaved on one side due to ground water. The point is that if the tile is level, the pool looks level. But if the pool is level and the tile is not level, the pool looks unleveled.

Let’s go back to our conversation about time savings at the jobsite. Remember we said that installing tile in the traditional fashion with thinset and grout requires a lot of special skill? In comparison, installing tile on a fiberglass shell is a breeze!!! Because the waterline is used as the level, it is much easier to get the tile even when compared to tiling and empty pool. Silicone adhesive is used to attach the pool tile, so there is no mixing or toweling skills needed. These adhesives are exceptional for bonding to the fiberglass pool surface and require minimum surface preparation. Grouting is done with a similar colored silicone material, and is easy to apply as well. Both the tile adhesive and the grout form an impenetrable water barrier, so pool tile coming off during a winter freeze is unheard of with this type of installation.

In the end, level tile for any swimming pool depends only on how the tile is installed. At Trilogy Pools, we recommend that your tile be installed at the jobsite, regardless of what anyone may tell you. There is no advantage to installation at the factory and a huge DISADVANTAGE when consideration is given to the tile being level on the pool. Silicone adhesive has an excellent cure rate in the field and proper surface preparation is easy to achieve at the jobsite.

After all is said and done, you want the tile to add beauty and accent your new pool, not be a constant example of how NOT to do something. Why become another statistic on unleveled pool tile? Insist that your pool builder take the time to install it exactly how it is installed on every concrete pool across the country: at the jobsite.