General:

Bituminous paints do not lend themselves to overcoating with ordinary decorative paints, as they usually bleed through after a time and stain the finishing coat brown. Bituminous paints have the disadvantage of being very thermoplastic and finishing coats that cannot cope with the expansion and contraction will tend to crack.

Where removal of the coating is not possible, the continued use of a bituminous material is advised. If the bulk of the bitumen has been removed, painting can be carried out reasonably successfully. Creosote or similar wood preservatives cause discolouration (bleeding) and slow drying of ordinary decorative paints.

When aged, they can be painted reasonably successfully over a suitable sealer.

Preparation:
Painting over thick, soft bituminous coatings or over freshly creosoted timber is not advised. If the bitumen coating is thin and hard, and the creosote well aged, clean down to remove all dirt, dust and grease. Scrape off all loose and flaking material to a firm base.

Previously painted:
Sweep to remove loose paint, dust, dirt and gravel.