levelling compound

I few years back I installed a floating floor using 18mm sloid oak planks from Wickes. I used fibre board sheets as underlay. The actual floor is made from polished asphalt. I've never been happy with the amount the timber flexed while walking on it. I didn't check how level the asphalt was...

I live in a high0rise ex-council flat. It has concrete floors wih Marley tiles. The living room floor has under-floor heating, and access panels can be lifted to access the inner workings. This heating system is not in use and never will be again. The panels do not fit exactly flush with the...