Revisions log for Answer #538
This is the answer to the question Is it necessary to do horizontal waterproofing of the floors in the garage?
Revision 1
The garage is not a dwelling house!
In this respect, sealing inside the floor structure is not required.
An 18 cm thick screed? How is that supposed to work? With a cement screed thickness of 10 cm it is already difficult to sufficiently seal the bottom screed cover. No more than 10 cm will work. No screed layer will do it that way.
The other question is whether it should be a bonding screed or a screed on a separating layer.
A bonded screed usually requires 30 to 50 mm.
An 18 cm screed will crack like a loaf of bread when it dries, so it will be a joy.
My suggestion:
A 35mm cement screed, no waterproofing, no intermediate film, no slope.
But instead requires sufficient surface protection in the form of a thick enough coat of concrete paint. Sanding must be done in advance, otherwise you can do without this step.