tile renovation

Hi All, I am doing up our new but 50 year old dormer bungalow and need some advice on the floors. The upstairs floor is sagging and appears to have undersized joists (16" centres, ~5.2m span, 2x7" joists). To complicate matters, the area is divided by two partition walls (bathroom and...

Hello all - have discovers the below tiled floor from the early 1900s under the bathroom floor. Looking for advice on how to clean them up? Is this a chemical fix or do they need some sort of heavy abrasive? Any advice from anyone who may have done this before or is in the tile trade!