Problems With Clay Building Bricks and Mortar

Freeze thaw damage (spalling) and lime runs.

.1 – Freeze Thaw Damage Due to Excessive Water Accumulation.

2 – Discolorations Including Efflorescence, Lime Runs, and Salt Staining.

3 – Cracking Patterns, Face Cracks, Chiping, Settlement, Abrasion, and Impact.

4 – Mortar Recession, Falling Bricks, Leaning Walls, Incompatible Materials, and Visually Displeasing Repairs.

5 – As-Built Construction Not Meeting Brick Industry Best Practices.

And Many More . . .

Leaning Walls or Chimneys and Loose Bricks Imply That Safety Issues Should Be Immediately Addressed!

Seek the guidance from a qualified Structural Engineer and/or Public Safety Officials immediately. Restrict access to any areas that could be accessible to falling bricks.

Job Specifications

Construction documents include specification manuals and drawings that reference building codes, material standards, and best industry practices. Best practices in brick construction are published by the Brick Industry Association (BIA) in the form of Technical Notes (see http://www.gobrick.com/read-research/technical-notes). Of particular interest are Note 7 (series), Water Penetration Resistance, Note 20, Cleaning of Brickwork, and Note 46, Maintenance of Brick Masonry.

Problems – Who’s at Fault?

  • If facing bricks meet Grade SW criteria in ASTM C216, if design drawings specify details as given in BIA Technical Notes, and if the as-constructed building conforms to drawings and specifications, brick should not experience problems and should “last” according to the manufacturer;s warranty (usually 50 years or greater). Most industry publications indicate a life of facing bricks of 100 years.
  • If masonry construction is deficient, cleaning is inappropriate, impermeable coatings (paints, sealants, anti-graffiti) are used, and/or if mortar materials tend to release soluble calcium, efflorescence, spalling, and mortar joint cracking are possible. While many excellent mason contractors are in business, the average quality of masonry work may have declined in the last 20 years.
  • If as-built construction is deficient in terms of flashing, drip edges, and weep holes, water accumulation in the walls can lead to problems such as freezing and thawing defects – like spalling and cracking. It can take several years after construction for defects to be notable. Water impingement and snow pooling also cause freeze-thaw problems.
  • If maintenance us not performed as provided in BIA Tech Note 46, certain problems can develop.

The Bottom Line – Are My Brick “OK”?

  • Brick made before about 1955 exhibited variability. Modern brick are almost always made in tunnel kilns with uniform heat distribution providing for physical properties with limited known variations. It is rare for bricks to be improperly or unsuitably manufactured (i.e., “not merchantable”).
  • However, one estimate given by an eminent professor suggests that somewhat less than 15 percent of brick structures will experience problems – suggesting that many problems result from as-built construction. These problems usually involve excessive water saturation.

Special Considerations for Historic Buildings/Bricks and Mortars

The philosophy in the Secretary’s Standards for Historic Preservation is to “do no harm” in repairs. The National Park Services Preservation Brief 2 is entitled “Repointing Mortar Joints in Historic Masonry Buildings.” Unfortunately, no guidance is provided for repairs involving replacement bricks. Using “incompatible” materials can result in harm to the building in 5-15 YEARS after the repairs, i.e after the building has experienced multiple thermal expansions and contractions. To prevent these “harms”, characterization of the bricks and/or mortar are required.