General:

Brickwork presents a particularly variable surface for painting and often paint failures may be isolated to individual bricks owing to great differences in porosity, or to the presence of salts causing efflorescence with its attendant flaking, or the presence of coloured substances such as iron salts causing severe staining especially of water-based paints. Certain types of bricks have highly glazed surfaces and offer a poor key for paint systems. In addition, the greasy film of firmly adherent dirt and grime may cause subsequent flaking. Old exposed brickwork may have a loose powdery surface.

Preparation:

New:
Remove dust, dirt, plaster splashes.

Previously limewashed or distempered:
Remove to bare surface by wire brushing, scraping or washing.

Previously oil, alkyd, P.V.A. or acrylic painted:
If in poor condition remove to original surface; if in good condition clean to remove dirt, grease, etc.