There might be some times that the shower tray you are using is flexing in the middle because of the weight or other problems.
shower tray problems
You cannot argue that an acrylic shower tray is not widely used (irrespective of whether you love them or hate them). When constructing a new single-family home in the suburbs or refurbishing hundreds of hotel tub/shower units, acrylic shower trays are frequently employed. Acrylic shower trays have many advantages, but just like you and I, they also have drawbacks. If you don't know what you're doing and aren't cautious, these product defects might cause significant issues. The worst thing that may happen to a shower tray is cracking. This can occur if the material is too thin and buckles, if the framework beneath the acrylic shower tray was inadequately constructed, or if the installation was performed incorrectly. Not all acrylic cookware is identical. The material thickness of these shower trays is variable. Some are constructed with "sub-structures" that provide support, while others require a mortar base. Regardless of the system you select, you will need a solid acrylic shower tray that WILL NOT CRACK! Let's confront facts. To create acrylic shower trays, a mold is utilized. These molds are designed and manufactured at a high cost. They want to get the most use out of these molds to maximize their investment. So, in your opinion, what is wrong with this plan? Thus, it is evident that these old molds may have been overused. Everybody evolves. Our needs alter with time (just think about how flexible you "used to be" when you cheered or played football in high school – oops, sorry to make you sad). When you were younger, a 5-inch-tall, prefabricated step-over curb wasn't a huge concern. However, you (or a family member) now require a lower threshold for more secure admission. You don't need to end up in the hospital because you slid entering or exiting the building. 
cracked shower tray
A shower tray is built to resist the weight of a person in addition to the pressure of a steady stream of water that is directed toward it. These two forces apply a significant amount of force that acts in a downward direction. No matter how neatly the shower tray was placed, it will ultimately twist or warp. This cannot be avoided. As a consequence of this tremor, minuscule fractures or lines of fracture have developed in the rock. If you take care of your acrylic shower tray and maintain it properly, you can add up to ten years to its usable life. If a shower tray is built on an uneven base or isn't correctly fastened to the floor and walls on all sides, this twisting can happen considerably more quickly, and the cracks that emerge can be much more severe. A minor fissure in the shower tray has the potential to rapidly worsen, which can result in water leaking into your shower tray. It is essential that you do so because each time you stand in the shower, you exert pressure on the same side of the crack, which could lead it to expand and become deeper over time. If you don't do this, the crack will get worse over time. An additional problem with a cracked shower tray is that, at first appearance, the crack might not seem to be particularly deep or extensive. When you put weight on the space or crack, such as when you are in the shower, it is possible that it will appear to be much larger than it actually is. Not only the area where water tends to pool is at risk of developing a leak in the shower tray; cracks can appear anywhere in the tray. Even if only a little amount of water is allowed to seep through, over time this could lead to rot and mold. If you do this, you put the structural integrity of your subfloor in considerable jeopardy. Both wooden and concrete floors are prone to damage from water in the same proportions. 
shower tray repair kit
The finish on an acrylic unit is harder than the finish on a gel-coated fiberglass unit. The color of an acrylic shower tray is consistent throughout the entirety of the material, whereas the color of a fiberglass unit is only present in the gel coat that is applied on top. Acrylic is more durable than glass but is slightly more brittle. Acrylic may be easier to repair than fiberglass due to the fact that it is a solid color; however, there are fewer color options available for acrylic repair kits. Because you use the shower tray on a daily basis despite the fact that it is broken, you do not have the luxury of waiting for expensive repair companies to arrive. But don't worry about it, because that won't be a problem at all. If you purchase a shower tray repair kit, you will be able to make repairs to any damage in under an hour. This speed is unrivaled by any other kit currently available; it represents a significant technological advancement. The repair kit provides not only the necessary tools but also a piece of epoxy putty, which can be used to seal a hole that is allowing water to leak out or simply to reinforce an area that has been damaged. The kit comes with a sample bottle of new Bathroom Brightener, which, when combined with the Acrylic Polish, will give the surface a clean, high-gloss finish while also protecting it from the dirt that accumulates over time. This is a brand-new addition to the kit, which also includes a free sample bottle. The kits come with photo instructions that are simple to understand and follow, as well as a Hints & Tips leaflet that will assist you in making a successful repair to your device. You can get a repair kit to fix and make your shower tray all new. 