I've just purchased a new flat and plan to makeover everything eventually. I've noticed that the shower has a few cracks along some tiles. https://imgur.com/pUOXH8K https://imgur.com/KMLzpaV Though I understand there there could be water damage. **I don't want to replace any whole tiles yet**... Is there anything I can use to fill in the crack to at least make it waterproof? Went to screwfix and was recommended to use this. But I noticed it says grout? https://www.screwfix.com/p/mapei-waterproof-fix-grout-white-1-5kg/64982 Would this be suitable to spread over the cracked tile. And then wipe over with a damp cloth to even it out?