We are thinking of laying a wood laminate floor in our rented house. At the moment it is carpeted, with underlay, on top of concrete. The carpet is quite thin. If we give the carpet a good shampoo, is it ok to put the floor on top of the carpet, to all intents using this as an underlay for the floor.
Using a carpet underlay or a carpet as underlayment for wooden flooring is asking for trouble I'm afraid.
Cleaning a carpet will never get rid of all the dust, dirt (and bugs) it has gathered over its lifetime.
Best is to remove it, including the carpet underlayment and start 'a fresh'.
Wood You Like Ltd