Has this parquet flooring been installed properly?

Hello questioner. Regardless of the further, previous feedback, here is my expert opinion: ---------------- 1. What are unevennesses, how were they determined, then HOW were they measured and above all: how are they eliminated?? Unevennesses in the sense of limit values of surface unevenness according to DIN 19202 are checked with a long straightedge or a sufficiently long measuring rod (or spirit level). If they are bulge-like high points, which I suspect in this case, it is technically a "high point," which according to the flatness standard is not considered an unevenness. Nevertheless, this does not mean that every high point could not be a defect and would have to be accepted! Take for example the photo showing the parquet surface and the baseboard, with an "open joint" under the baseboard at the transition. Such unevennesses in glued parquet certainly lie in the flatness of the substrate, thus in the smoothed screed surface. Whether this is a defect or an aspect to be corrected depends on the point gauge and measuring point spacing, how it was measured. In most cases, the cause of such joint formations lies in the drying-related shrinkage of the screed and is unavoidable. Conclusion here: not necessarily a defect, according to photo 691092-1.jpg a defect would undoubtedly be denied. ------------------- 2. The stripe-like processing according to photo 20250628_192154.jpg is an optical aspect (I avoid the term DEFECT here, as it is a legal term reserved only for lawyers), which is by no means okay, but could only be accomplished with considerable effort, partly by re-laying. Let us use the term "optical defect" here for clarification. This is certainly a blot on the installer’s reputation, without a doubt, because he did not calculate beforehand where he would end up with the last row of boards based on the board widths. In this case, it was too tight; he should have started initially with half a board width. -------------------------------- IMG_20250701_150134_748.jpg 3. Even with glued parquet, a 5mm expansion gap to the wall should remain. This was not done here; furthermore, the white sealant is again not an aesthetic highlight. There are also color-matched sealants, matching the parquet appearance. ------------------------------ 4. The actual main problem, also for later times, I see in photo 691092-2.jpg. If the red-framed area has bulged, then this is certainly due to a rear detachment of the affected parquet boards. That means: either the parquet adhesive failed for reasons which I do not want to list here individually, or the upper edge zone of the subfloor. This can only be recognized if the spot is opened and the fracture zone evaluated. What does this mean: was it repaired? I can only repair something reliably if I have recognized the cause of the (in this case) detachment. And if the parquet boards have actually detached on the back, how is one supposed to repair without partly dismantling the boards? Although this is possible by injection with a reactive resin, for example with PMMA, it is completely uncertain whether the attempt will also have a lasting success. I do not want to cause anxiety here. My suggestion is that as soon as a larger area bulges again, send a registered letter to the parquet company and necessarily include the phrase "notice of defect with request for repair within 4 weeks of receipt" in the subject line. With the letter you first stop the limitation period of (usually) 5 years, and you can prove with the letter that you insist on fulfillment. If you only call, the whole thing gets lost in the fog of non-commitment and/or forgetfulness. ---------------------------- Good luck: KlaRa