Laying laminate over carpet

Hello Yogi,

You cannot measure flatness with carpet flooring, because then you measure the flatness of the carpet and not of the subfloor.
Who guarantees you that no moisture is penetrating from below, who guarantees you that you did not have a water pipe break, who guarantees you that a bucket of water did not spill recently.

The testing obligations are nominally regulated and must be carried out properly. If you have not performed a CM protocol and a dispute arises, then you will have lost with any expert.

Of course, you can do anything, but it is not permissible, and as soon as a dispute arises, you have the short end of the stick.

Which customer would please pay you for a moisture measurement in their living room where a carpet has been lying for years??? If there had been a pipe break, the people would know and the carpet certainly would no longer be there. In a rental apartment, I as a tenant was not allowed to remove the existing wall-to-wall carpet and laid the laminate directly on top of it. It has now been almost 7 years without damage.

Hello Yogi,

according to VOB DIN 18356 point 4.1.6, the first measurement is a supplementary service and must be carried out free of charge; it is to be recorded and handed over to the customer along with the maintenance instructions or upon request.

What is that supposed to achieve with an old screed? With a new screed I understand it. Where is the moisture supposed to come from? And what about on wooden floorboards? What would you do if you were supposed to lay laminate for a tenant and the carpet is part of the apartment and must not be removed? I don't understand what is supposed to happen there.

Hello Yogi,

a moisture measurement can also be carried out on wooden flooring, but not a CM measurement.

What it achieves is not the question, I want to protect you here, as a potential floor layer, from mistakes, because you never know in advance whether there will be trouble later and if you have not carried out a measurement, you have very likely lost every process.

Putting aside the question of allowed or not... We had a low-pile carpet in the house and laid the laminate over it. Aside from the fact that all the doors had to be hung higher or shortened, I have had no problems so far. And the laminate has now been in place for 7 years.