Floorboards on concrete slab Help, advice, information, answers and tips on all types of flooring from laminate and carpet to timber and vinyl

[Sussex345]

A late 1960s flat with a concrete slab separating the flats. On the concrete slab is a floating batten 2” x 2” subframe with regular 6” floorboards on top. Due to age and wear and tear in some areas the floor moves up and down when walking. Does anyone know of how it can be stabilised without ripping it all up at great expense.

[stoneyboy]

Hi sussex345,
Due to the age of your flat it is likely that the floor and framing were added at a later date.
There could be a number of reasons why the floor is flexing and the cause will dictate how you deal with the problem. If the flexing is because: the floor boards are insufficiently fixed to the framework more fixings could be added; if the framework is not fixed to the floor you could try drilling through the boards and frame then injecting expanding foam; if the original floor was Lino tiles or there is a screed on the structural concrete slab and these have become unstuck lifting the floor may be your only option.
The problem with trying to add additional fixings is that you will not know what services are run through the floor structure - there may be cables or pipes run through the framework or in the concrete screed. Possibly best to lift one floorboard to determine the cause.
Regards S