get some mats, weights/plates are meant to be dropped/abused - they don't lose their efficiency due to cosmetic damage.

so get thick mats to protect your floor, as you also need to be able to drop your DB on a dime for safety purposes, you wouldn't want to mess up your shoulder/wrists just because you're trying to "baby" the weights.

Also, something is really wrong if you could 10-12rep 25kg, but couldn't even 1-5 rep a 27kg. Usually if someone could rep til 10+ it would mean the weight is already too light and it's time to add weight until you could max out at 9-10reps again. Progressive overload.