Hello,
I've had to take up my kitchen floor to have some pipework rerouted and am now faced with a section of original concrete floor by the sink and the the rest floor boards on joists. The flat is about 100 years old. The floorboards slope down to about an inch lower than the concrete where they meet. Do I lay thick ply straight over the lot or should I lay some concrete/screed over the dropped floorboards to get the level then ply over that?