Preventative Maintenance
Problem Diagnosis and Masonry Repair
Maintenance / Inspection Annually – Exterior- Mortar and unit condition
- Presence of efflorescence (surface salt deposits) or stains
- Presence of insects or vermin
- Caulking and sealants condition
- Plant growth on walls, i.e. vines
- Coating conditions
- Parapet cap and copings
- Roof membrane condition
- Slope of ground away from building
- Anchorage of signs and lights
- Maintenance / Inspection Bi-Annually – Exterior
- Weep holes to allow for air and water drainage
- Roof drains, gutters, downspouts, splash block
- Window and door flashing
- Window and door caulking and weather stripping
- Feel for drafts at doors and windows
- Check for plumb and alignment
Maintenance / Inspection Interior- Signs of water leakage and mold growth
- Condition of sump pump and French drain
- Have chimney flue inspected and cleaned
- Common Causes of Leaks
- Use of wall system that does not have a positive method of controlling water
- Exterior wythe of highly absorptive materials
- Poor bond between units and mortar or incompletely filled mortar joints
- Improper installation of flashing and weep holes
- Missing or failed sealants
- Proper Flashing
- Top edge is sealed to prevent water from passing behind the flashing
- Outer edge of horizontal leg extends to or beyond outside face of masonry
- Continuous at inside and outside corners
Laps are sealed to prevent water from passing between layers- End dams at horizontal terminations
- Caulking / Sealants
- Common causes of caulking / sealant failures
- Deterioration due to age
- Loss of adhesion due to improper sealant profile (too thick or too thin)
- Loss of adhesion due to inadequate surface to which to bond
- Omission
- Common Causes of Cracking
- Restraint of clay masonry volume expansion
- Restraint of concrete masonry shrinkage
- Failure to isolate clay masonry from concrete masonry in the same wythe, or anchorage between wythes that is too stiff axially
- Settlement or other loss of support
- Structural overload
- Corrosion of embedded metals
- Common Causes of Spalling (Flaking or Chipping)
- Damage due to cyclic freezing (expansion) and thawing of water in the pores of the masonry unit, particularly when masonry is treated with low vapor permeability coating
- Structural stress, such as that imposed by restraint of masonry volume expansion or corrosion expansion of embedded metals
- Use of inappropriate repointing mortar
- Common Causes of Staining
- Excessive moisture on, or traveling through the masonry (moisture sources may be internal or external)
- Pollution
- Organic growth
- Corrosion of embedded metals
- Contact with undiluted acids
- Displacement Causes
- Restraint of clay masonry volume expansion
- Inadequate anchors for lateral support
- Freezing action
- Corrosion expansion of steel supports
Repointing of Mortar Joints- Most common repair – mortar is intended to be the “weak link” in masonry construction
- Generally, not needed for about 50 years
- Repair mortar must be compatible with original mortar
- Displacement / Leaning
- Masonry that has displaced generally cannot be “pulled back” to its original position without causing more damage
- Displaced or tilting masonry can be stabilized in place, preventing additional movement, particularly if the masonry is not load-bearing
- To Coat or Not to Coat
- General categories of coatings
- Clear, penetrating water-repellents
- Silane or silane/siloxane preblended are preferred
- Film forming
- Elastomeric
- Cementitious
- Prime concern: permeability
- Permeability of 0.98 or greater as measured by ASTM E96 is desirable
- Exception: anti-graffiti coatings
- Consider the masonry material
- Clay masonry (face brick, common brick)
- Concrete masonry and cast stone masonry
- Dimension stone masonry
- Consider the historic performance of the coating
- Coatings do not compensate for poor workmanship!