About 3 months ago I had a Conservatory built it has French doors that step down onto a concrete floor I want to fit a floor with floorboards that raises the level about 4 inches. The concrete base has a damproof membrain. The concrete is not quite level, before the Conservatory was added the rainwater settled at one side. What is the best way to fit the wooden floor. I thought wooden beams screwed to the concrete and shims under the beams to level the any variations.