Masonry is made up of a number of items including brick, stone, terra cotta, concrete, stucco, tile, and mortar. Masonry is used on cornices, pediments, lintels, sills, and decorative features, as well as for wall surfaces. Colour, texture, mortar joint type, and patterns of the masonry help to define overall characteristics of a building. Brick can be used for the construction of building walls, retaining walls, fencing, and chimneys.
Look for damage caused by the improper cleaning such as chipped or pitted brick, washed-out mortar, rounded edges of brick, or, a residue or film.
Maintenance – as with so many things, proper maintenance is the key to longevity. Here are some guidelines:
- Respect and retain, where possible, all masonry elements that are important in defining the overall character of the building.
- Monitor water drainage and the effects of weather on mortar ensuring there’s no wear & tear.
- Direct water away from the base of a wall by at least six feet by ensuring proper lot grading and extensions on downspouts.
- Install a damp-proof course just above the ground level to prevent dampness from wicking up.
- Don’t apply waterproof, water repellent, or sealants in an effort to stop moisture problems as they often trap moisture inside the masonry and cause spalling (the breaking off of the brick surface).
- Repair or replace leaking roofs, eavestroughs and downspouts. Ensure proper flashing is in place.
- Repair all cracks in masonry and joints to prevent moisture penetration.
- Caulk all joints between masonry and other building materials, such as, window frames to prevent water penetration.
Cleaning – This should be done only when necessary to stop wear and tear or to remove heavy soiling. Some procedures to follow include:
- Clean unpainted masonry using the least abrasive method possible, for example, a low pressure water wash with detergents and natural bristle brushes.
- Test cleaners on a small unnoticeable spot of the building, using a non-abrasive method. Try a more abrasive way only if necessary. Let your test spot dry thoroughly before carrying on and check for surface deterioration or discolouration.
- Detergents and pressure washing of older brick may cause damage, as the brick is too soft.
- Sandblasting, high-pressure washes and other abrasive cleaning methods should not be used, as it wears the protective surface of the brick allowing, for example, moisture to be wicked up. Any freeze-thaw action then causes spalling (the breaking off if the brick surface).
- Chemical cleaners should be used sparingly and not where damage masonry is caused. Chemical cleaners should be washed off and removed from the masonry as soon as recommended.
- Don’t use water or water-based chemicals in freezing temperatures.
Painting & Waterproofing
- As a general rule, leave unpainted masonry unpainted.
- Remove deteriorated paint only to the next sound layer by hand scraping. Don’t remove paint that is well adhered, as this could damage the masonry.
- If masonry needs repainting, clean it thoroughly, allow it to dry, prime the surface with an appropriate masonry primer, and repaint with appropriate masonry paint. Use water-repellent breathable paint coatings, only as a last resort.
Repointing — Disintegrating mortar, cracks in mortar joints, loose bricks, or damaged plasterwork may signal the need for repair of masonry.
- Remove deteriorated mortar by carefully hand raking the joints to avoid damaging the masonry. Don’t use power tools and be mindful of the surrounding masonry.
- Duplicate existing mortar in strength. Do not repoint with stronger mortar as the brick expands and contracts with temperature. Do not use synthetic caulking or sealants.
- Duplicate the composition of the mortar. Older brick buildings have a higher lime and sand content than new ones.
- Duplicate the appearance of old mortar joints in width and profile. Cut out old mortar to a depth of one inch.
- Repair damaged masonry elements if possible, by patching, piecing in, or, joining to match the original instead of replacing a masonry feature.
- Repair stucco by removing loose material and patching with a new material that is similar in composition, colour, and texture.
- Patch stones in small areas with a cement-like material that like mortar should be weaker than the masonry being repaired.
- Consider using epoxies for the repair of broken stone or carved details.