- Damage to masonry is usually caused by movement or water infiltration. Causes should be identified and stopped before undertaking repairs.
- If mortar is missing or loose, the joints should be cleaned out and repointed using a mortar mix which closely matches the composition and color of the original.
- When removing mortar from joints, take care not to damage the brick edges.
- Whenever partial or total foundation replacement is required, the new foundation walls should be faced in materials which match the original in appearance. Reuse of the original materials on the face of the foundation is preferable.
- Whenever replacement brick or stone is needed, use salvaged or new material which closely matches the original in size, color and texture.
- Whenever masonry has been painted, it is usually advisable to repaint after removing all loose paint. Old paint which is firmly fixed to the masonry will usually serve as an adequate surface for repainting. Methods which attempt to remove all evidence of old paint can damage the masonry (softer masonry is more prone to damage).
- Any cleaning should be done with the gentlest method possible and should be stopped at the first evidence of damage to the masonry. Test patches should be used to assess the effect of any proposed cleaning method.
- Bricks should not be replaced unless excessively spalled or cracked. Consider reversing a brick to expose its good surface before replacing it with a new brick.
- When selecting a replacement brick, avoid using what is commonly called "antique" brick which consists of a mixture of bricks in a wide range of different colors and types. Bricks on historic buildings were usually uniform in color.
- Masonry should not be replaced or covered over simply to eliminate evidence of past cracks, repairs, and alterations.
- The cleaning or dirt, grit and weathering from masonry surfaces is usually not necessary unless it is causing damage or is unsightly. In any case, the goal should not be to make the masonry look new. Old masonry neither can nor should regain its original appearance.
- Avoid power grinders. Mechanical equipment is cumbersome and even the most skilled worker will tire or slip and cause irreversible damage.
- Avoid sandblasting, high pressure water blasting (over 600 psi), grinding, and harsh chemicals.
- Waterpoof and water repellant coatings should be avoided. They are generally not needed and can potentially cause serious damage to the masonry. Also avoid covering masonry with tar or cement coatings.