Does preprimed hardboard siding have to be primed after it is installed on a house?
It is always a good idea to check the siding manufacturers’ recommendations before painting, but in most situations it won’t hurt to apply a coat of exterior alkyd primer before applying two coats of an acrylic latex topcoat. A coat of primer will promote better adhesion of the topcoat and assure that the hardboard, particularly the bottom edge, is adequately sealed from the elements.
