My husband layed a sub floor and porcelain tiles in my mother's kitchen, not realizing that there would be a big difference in height where the tiles meet an existing floor. How would he put trim so that there wouldn't be such a sharp edge (ie - where the kitchen floor meets the living room floor, etc. Elderly people will be living in the house and I wouldn't want them tripping. I'm hoping but not sure if I've explained this right.