Wet Or Dry - How To Install Vinyl Pool Step Flanges
One of the very first discrepancies that I remember encountering in the pool industry relates to how you install vinyl liners over in-wall steps. Installing a pool liner is not such a difficult task, and we all (more or less) do it the same way...except when it comes to installing the steps. The process used for installing the liner into the step flange changes virtually from company to company. It seems that this is one of the areas of the pool industry which lacks congruency of technical process...every company that installs liners is left to develop an in-house method that gets the job done, and not all of these methods are created equal.
Installing a liner over in-wall steps is not rocket science...but some ways are better than others. The problem is that most pool companies do not install liners to be 100% leak free, and for maximum longevity, but instead the main goal is (of course) to make money. If the goal was to make the liner installation as close to leak free as possible, and last as long as possible, then I guarantee many pool companies would change their process to one that takes a little longer to do. If you only install a handful of liners per year then it doesn't make a huge difference to take some extra time on each installation...but if you install hundreds or even thousands of liners per year then you need to shave the process down to the most lean, most efficient installation possible.
How Long Does It Take To Install A Pool Liner? - When I first started installing liners in the pool industry we would take about two days to install a liner. I was working with my Uncle who had retired from pool building and ran a small service company that helped to fill his days and keep us busy. I can't recall exactly what we would do for two days as this was many years ago, but it seems crazy to me that it would take us that long to get the job done. Later in my career I worked as a lead installer for a very busy company which required that I installed between two to three liners per day, every day, for the entire summer. If you have not worked in this mass-market liner installation industry then you may struggle to understand how it is even possible to install liners so fast.
How Long Does It take To Install A Vinyl Liner
If you want to install a liner as fast and efficiently as possible then the process needs to be streamlined. Having access to every type of coping, hardware, liner lock etc. produced since the 1970's on hand at all times certainly helps to make this possible. Assuming that no surprise deficiencies are found during the installation then the timeline should look something like this:
Hour 1 - Drain the entire pool with a 4" trash pump. With a large gas powered pump like this you can move an incredible amount of water. Within an hour the pool is empty and the old liner has been cut out. A busy company will have a crew that only does this one job. Just driving from pool to pool and draining / removing the old liner. This is usually not a skilled liner installer on this crew, and so they do not remove any flanges...simply cut out around every flange.
Hour 2 - Coming behind the liner stripping crew would be the liner installer plus one helper. Assuming that the pool does not have any deficiencies which require repairs before the liner can be installed, within an hour the pool can be taped along the coping and wall seams, swept, scraped and washed. As the helper is vacuuming the bottom of the pool, the skilled installer is removing flanges and installing new gaskets in preparation for dropping the liner.
Hour 3 - The pool has now been taped, washed, swept and cleaned and all new gaskets installed on the skimmers, returns, lights and main drains. If everything has gone smoothly then by hour three you are able to open the liner and start hanging it in the pool. From the time the liner box is opened, until the liner vacuums are running, is only about 20 or 30 minutes for a skilled liner installation crew of two people. Start the water running into the pool and off to the next installation.
If this sounds very fast for a liner installation to you...I agree. I am not saying that this is the best way to install a liner, just that this is the timeline that many busy pool companies follow in order to be profitable on liner installations. Again, when I was young, my Uncle and I would winterize three pools per day. It felt like a lot of work at the time. Now, myself and one decent helper can fully close, winterize and cover 12 to 14 pools every day. Every single day. Unless you have worked for a company where you had to shave your process down to the absolute most efficient work possible you might not feel this is possible...but it is. Assuming the pool has been drained below the return height, I can walk up to a pool system with my channel locks, a 7/16" wrench, a 1/2" wrench, a 9/16" wrench and a blower vac and have the pump, filter, heater and all plumbing lines blown and winterized easily in under five minutes. A dream pool like a 12x24' rectangle with a simple system and a safety cover can be drained, winterized and covered in about 15 to 20 minutes total, by two people, from arrival on site to driving away to the next address. This includes ZERO cut corners...just highly efficient work with some serious hustle. Unfortunately when it comes to installing liners there is a lot more potential for problems as compared to a simple winterizing.
Of course not all vinyl installations will take from three to six hours to complete, but this is a fairly good range for the different spectrums of vinyl pools you will encounter. Many will require extensive repairs to the walls and floors, as well as any flanges which are found to be deficient during this process, which will all take more time. Some will be harder to clean and prepare for the new liner than others. Three hours represents the "ideal pool" minimum time to install a liner, while even the most difficult residential pools can be prepped and hung in under six hours or so. If you are interesting in seeing more about vinyl liner installations then read this article about how to install a pool liner.
Installing Vinyl Pool Steps - Wet VS. Dry
As described with the analogy of winterizing pools, when you become proficient with installing liners you can shave a lot of time from the process. This is the main focus of this article. When it comes to shaving time off of a liner installation one of the biggest time-wasters is the steps. Since the vast majority of vinyl pools have in-wall steps this means that if you are going to install multiple liners every day then you need to find a faster way to cut in the stairs. This is how most liner installers end up cutting in the steps dry versus wet.
Wet Steps Installation - When you install vinyl pool steps "wet" this means that you run the liner vacuums and raise the water level in the pool until it is covering the floor of the shallow end with at least a few inches of water. This allows the weight of the water to naturally stretch the liner into place, most especially at the cove where the floor meets the wall, underneath the bottom flange of the steps. With thousands of pounds of water pushing the vinyl into place you can be sure the liner is set well before installing the step flange.
Dry Steps Installation - When you install vinyl steps "dry" this means that as soon as you hang the liner and turn on the vacuums, you install the step flange right away. Yes it is possible to do this, and many installers choose this method as it saves a TON of time waiting for a water truck to fill the pool, or for the customers hose to fill the pool to the shallow end. Without the added benefit of the water weight holding the liner in place, the step flange is held in place partially by the liner vacuums, as well as being manually manipulated, pushed and stepped into position as the flange is installed.
As someone who has installed thousands of pool liners, and having used both methods (wet VS dry) hundreds of times, there is no doubt to me that installing vinyl pool liners dry increases the potential for leaks in the pool. It is my opinion that a vinyl liner installed dry over steps will fail and leak sooner than a liner which was installed wet. Sure it is possible to hold a liner in place and install the step flange...again I have done this literally hundreds of times myself. Especially on a hot and sunny day, with a liner that fits perfectly in the pool, the step flanges will install like butter. So where is the problem?
The Problem With Dry Fit Liners
The problem with installing liner flanges totally dry is that the liner will continue to shift and move as the pool fills with water. This is the reason why you should not install the gaskets and faceplates on a new liner until the water level in the pool rises close to the flange you are installing. Sure there are many pool liner installers out there that install every last gasket and fitting immediately after hanging the liner. Does this make this process a good idea? Surely not. The weight of the water will pull and stretch the liner into every last nook and cranny of the pool shape. On a hot and sunny day the liner is so supple and easy to work with that you might think it is OK to install all of the flanges dry. But what happens at night as when the pool is colder and there is no sunlight? Well, it contracts, and the vinyl becomes stiff and much less inclined to stretch evenly.
The vast majority of liner installers reading this would never install a skimmer faceplate on an empty pool because they know that it is very likely the vinyl will pull and stretch, possibly causing a leak on the underside of the skimmer flange. So if the vast majority of liner installers would not install a skimmer flange on a dry pool, then why would it be OK to install the step flange - A MUCH larger flange and one FAR more likely to introduce a leak into the pool if the liner pulls or stretches around the flange? The answer, simply, is that it is faster. You can tell me that you have been installing liners dry for a million years and never have had a problem...but you will not convince me. A wet installed vinyl step will outlast a dry installed vinyl step every time. Getting the liner to fit as well as possible around the steps may be the single most important aspect to getting the longest life possible out of your new pool liner.
The Incredible Shrinking Liner - The reason why dry-fit liner installers "never have a problem" with their pools leaking around the steps is simply because it takes time for these leaks to develop. Sure it is possible, in an extreme situation, to introduce tearing and leaking around the step flange upon installation, but there is so much elasticity in the liner when it is new that the leaks do not tend to show up right away. As the plasticizers in the vinyl are released over time the vinyl will significantly lose elasticity and shrink. Any place where the liner is under stress becomes a potential leak location. When you install a liner dry over the steps, it is very likely that one day a leak will develop from the liner pulling away from the screws in the step flange.
The single most vulnerable area of your pool to experience a leak from a less-than-ideal liner installation is the steps. There are more screws in step flanges than in every other flange in the pool put together. Add to this the fact that there is (at most) a few inches of vertical wall height under the bottom flange before the vinyl transitions to the floor, and you have a recipe for disaster. If there is too much coving where the shallow end floor meets the bottom step flange then once the weight of the water pulls the liner into place, the liner will be stretched tight like a drum in this area.
Pool Liner Installation - Time VS. Quality
In my mind when you install a vinyl liner step flange "wet", this results in a higher quality installation than a step flange which has been installed "dry". The problem is that it takes longer to install the liner if you have to wait for the water level to come up. Liner installations are not a very profitable business and so many companies simply install the steps dry to save time. They probably won't leak right away, or maybe even for a few years, and so the warranty period for the installation will have long since expired.
Any time that you choose to follow a technical process for the expressed purpose of saving money, while sacrificing quality and longevity, you should re-evaluate your position. Allowing the liner to stretch naturally into place under the weight of the water in the pool is the best way to orient the fit before you start installing flanges and cutting the liner. If you are of the opinion that cutting in the steps dry is "fine" then why do you not install all of the flanges dry as soon as you drop the liner? And if you are a vinyl installer that installs the liner and all flanges immediately upon hanging the liner...do you trowel the concrete while it is still in the wheelbarrow to save time?
The need to be profitable is obviously critical to any company however if you need to sacrifice quality in order to make profit then you should find another line of work to be active in. Sure there will be exceptions to the rule in that sometimes you can get away with installing the step flanges dry without negative consequences down the road. Some pools have a lot of extra liner, depending on how it was measured, which can aid in reducing the strain put on the step flanges when they are cut in dry. Some pools have such good suction that the liner is basically tattooed to the floor, cove and walls, which makes it much easier to install the step flange dry. The secret to being a good vinyl liner installer is to be able to read the unique situation you are dealing with and make a choice on the fly that is the best for the pool...not for your pocket book.
Whenever I talk about this subject with other installers there is always some blow back from installers who insist that it is completely fine to install vinyl steps while the pool is still empty and dry. To these installers, I ask you, if you arrived to inspect a vinyl pool where the owner decided to drain the pool themselves only to discover that you "can't do that" to a vinyl pool...where would you look first to see if the liner has ripped? The step flange of course. It is the biggest flanged opening in the liner, and is usually oriented such that it can withstand the least adverse stretching and movement without failure. The height of the bottom horizontal flange above the shallow end floor is very important in particular, as it will be nearly impossible to manually press out the cove below the horizontal flange to the same extent that the weight of the water in the shallow end will. Even if the cove is non-existent, a vinyl liner needs to stretch naturally, as a whole, and installing such a large, integral component before the liner has finished stretching into place is, well, a short cut. This is why you do not simply install the liner and vacuums, and then cut in every flange right then and there...and you if you do install liners like this, then we will simply have to agree to disagree.
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