Rendering inside cow shed

Hi i have to go and look at job in the morning to render inside a cowshed,its already rendered apparantly so needs knocking off the loose and render.
Its having a fiberglass resin on top of the render when it is fully cured.
Will it be ok to use sand,cement and lime at 5.1.1 two coats or will it have to use purely a lime based render.
Thanks in advance.