Vinyl deforming under strong sunlight exposure?

A vinyl floor must be replaced and disposed of after 15-20 years, a parquet floor can be sanded.

For example: if you drop cutlery, etc., you get a dent, which happened to us after just one month. However, a scratch can simply be re-oiled. Vinyl is therefore more prone to scratches. Vinyl floors nowadays are very well made, but you only get the rustic variety with wood. Therefore, either natural stone or wood, but that is my opinion.

Vinyl is also commonly installed in cars. There you have the same temperatures. But since it is a soft and elastic plastic, not much really happens except that the plasticizers evaporate and the material eventually becomes brittle.

It is possible that the other manufacturer laminated the vinyl onto something and this could cause delaminations, etc. If it is only the planks, they withstand the sun and yes, it does get quite warm. The sun is quite intense.

I would like to correct that. Vinyl—short for polyvinyl chloride—is not elastic at all by itself. Only the added plasticizer turns the inherently brittle, hard material from impact-resistant to very soft and flexible. The more plasticizer it contains, the faster the material ages. The cheaper the plasticizer, the faster the material ages. Rigid PVC is known from dashboards or handles in cars, old roller shutter slats, wastewater and downpipes. That lasts a very long time and is also highly light- and weather-resistant. Soft PVC has a very high plasticizer content and is known as artificial leather or inflatable pool toys. The flooring lies somewhere in between depending on the manufacturer and area of application. For design floors, PVC is further mixed with dyes, pigments, fillers, etc. These thin sheets are—in the same way as wood in parquet—glued onto a carrier material made of wood. The layers of this sandwich made of plastic, adhesive, and wood carrier naturally react differently to heat and sunlight. The darker the material, the stronger the stresses between the plastic and the carrier. All plastics nowadays are more durable than in the 1970s, but if a manufacturer advises against installing the material in areas with strong sunlight exposure, then they know what their material can do, how long its service life is, and when the warranty expires. Plastics are considered nearly indestructible as far as waste is concerned, but their desired properties usually degrade after 10–20 years.

If you are already afraid of floors that cannot withstand 70 °C, how warm is it supposed to get in the room itself? If the floor is supposed to withstand 70 °C, the rest of the room would have to be unbearably hot. Some kind of sun-controlled shading should already be planned given these conditions, which would also somewhat relativize the floor problem.

I have already learned in the range hood thread that simple quotation marks are not necessarily perceived as a quote. That is why I even added a textual emphasis indicating that I AM QUOTING. It was of no use. I do not know how I can express myself so that everyone really understands me.

I do not compulsively look for arguments. I am a scientist and therefore interested in facts. I am interested in the experiences of others. I do not reject them but collect them. In the end, I decide which of them are transferable to me. For example, I am interested in how/where the evidence was provided whether emissions from vinyl are harmful or how to recognize the necessity of replacing vinyl.

Scientists in which field?

The problem is the VOCs - volatile organic compounds, which evaporate from all organic materials (i.e., everything except metal, stone, ceramic, glass). Either immediately or over time through the aging and decomposition processes of the individual components. Adhesives are particularly susceptible to decomposition processes, as are plasticizers. Formaldehyde, for example, was once a major issue in particle boards. The higher the concentration in the indoor air, the less healthy it is. The smaller and closer to the ground the occupants are, the more these substances are absorbed and accumulate in the body. And in new buildings, you don't just have a new element that emits, but hundreds. From cable sheaths to paints, upholstered furniture, seals, plaster and insulation materials, to new furniture and doors. No manufacturer tests the harmlessness of the aging processes of their materials. When the material is brittle, breaks, swells quickly, or changes its color, then it has reached the end of its lifespan and can no longer fulfill its function; however, these processes take several years.

Ask yourself the questions
Do you want to have a PVC floor in the house?
Do you and your children want to play and sit on the plasticizers?
Do you want the emissions in the room air?

Parquet can also discolor easily
Vinyl expands with heat. At friends’ houses, the floor installers made the expansion joints too small, which then becomes a bit wavy.

If the manufacturer advises against it, I would follow that.
We don’t have vinyl. On the one hand, we don’t want it, and on the other hand, our home builder didn’t offer it back then. In 2017, there was no one who met the criteria of being healthy to live with, ecological, and up to their quality standards.