Question
I have a well-established lawn on one side of my house, but unfortunately, I need to add about 2-3 inches of topsoil to improve the grade so water runs away from the house.  What is the best strategy for this: will the lawn grow up through the soil, should I reseed, or should I remove the sod and add it back once the top soil has been added.

Answer
Hi Andrew, Your choice depends on the type grass.  Fescue, blugrass and other cool season grasses, probably will not survive adding soil on top of the turf and you'd need to reseed.
Bermuda would come through.  Zoysia and St. Augustine would suffer, part would die, part would survive.  
Your best option is to remove the sod with a sod cutter, add your soil (the same type that is there) and then replace your sod.  Instant results and the happiest grass.  Jim