there is a new way of lifting concrete slabs they are using a type of spray foam once it is in there it will not start to disappear on you. they can inject it throw a carpet and when finished you wouldn't know they were ever there. pretty much no mess. Mud jacking is really messy and can take a long time to clean up and if you don't fix the cause of the under cutting then it starts all over again. If you were in Kamloops I could give you the number of a guy. check the phone book.