ᐅ Rebuilding the subfloor – original construction from 1955, finished with parquet flooring

Hello everyone,

I have been renovating an attic apartment in a multi-family building constructed in 1955 for the past few weeks.

At handover, there was floating parquet flooring installed... beneath it, carpet, linoleum, cardboard, and leveling compound were found. All these layers were professionally removed down to the original screed/concrete floor.

In one spot, you can see under this lowest floor layer, and soil is visible – photos attached.

Is this a problem? The next step will involve epoxy resin, sand, and a new screed/leveling compound, depending on the height. The final floor covering will be parquet.

Thanks for your assessment and tips!

Best regards,
SuperTech

Hello questioner.
What you are describing are the uncertainties and surprises that arise with almost any existing building. The new construction does not seem too complex to me based on the photos. But you need to know what you are doing—especially when giving advice. And for that, you should be familiar with the property.
Although a construction recommendation could be considered from a distance, it would not be reliable. Just ask an experienced flooring or parquet installation company, as they also know about floor constructions.
Ultimately, in this case, you also need to question what lies beneath the screed or floor slab, whether rising damp could become a problem for the new parquet floor, and so on.
I do not want to complicate matters, but from my own experience, a quick decision is not always the damage-free solution.
If one were to (just to give one example) prime the entire area after thorough sanding and vacuuming with an epoxy resin primer, then broadcast sand, and completely renovate the steps/foundation strips visible in the photos with a resin screed, moisture or other issues would no longer be a concern.
But resin screeds are not only problem solvers; above all, they are expensive.
Good luck: KlaRa