pool room metal door frame rusted out at bottom, how to fix?

[wozzzzza]

i have a pool pump room where the metal door frame is rusted out, i have replaced it once 7 years ago and rusted out again.
what is a good way to get this done so it doesn't rust out??
was thinking of filing it up with sand/cement and moulding it into a door frame so it never rusts, any other ideas??
one of the sides has a timber block going through its length.

[droog]

Even if the frame is filled it will still have potential to rust and may increase the potential by trapping moisture against the steel.

Hot dip galv, epoxy priming and top coat will all help but it’s the environment it’s in that is the issue.
Construction of the frame from material less prone to rust is the proper solution, eg stainless steel, timber, etc.

From the pictures looks like main area is where it contacts the floor, think of options where the steel will no longer extend down to the floor, eg concrete hob at the bottom.

[r3nov8or]

Aluminium, stainless steel, timber without trapped moisture/good ventilation.

"Doing the same thing and expecting a different result is the definition of insanity" or something to that effect