What can be done if the space under the floor boards (eg. 9 mm) for any reason (laying of pipes and others) is too low.
There are paving support pads with greater thickness (e.g. 14 mm), which is stackable, so that three paving support pads one on the other reach a level of 42 mm.
For even greater heights (for example, bringing the level of an balcony exit door to the terrace area), there are adjustable paving support pads (also with intermediate pieces), which altitudes above 100 mm can achive.