It depends.
When we were house hunting we looked at one house that was on a very flat lot. The lanai concrete slab was actually at ground level. It should have been above grade.
There was no provision to make rainwater from the roof to flow away from the house. In this case, rain gutters should have been installed.
The house we ultimately selected was on a hillside and the lanai floor was three feet above ground level. There was no need for gutters.
You have to evaluate your individual situation.
|