how do i prevent rot on a porch?
If built properly, a porch floor slopes away from the house, and (being a porch) is also covered by a roof, so it should only get incidental blowing rain, not the full brunt of every storm. The slope (1/8&quot; per foot, 1 inch in 8 feet) ensures that any water that lands on the porch drains off of it.
It's also common to oil (linseed oil) or paint the boards as well.