Masonry Magazine February 1992 Page. 51
Dallas Homebuilders
Honor Acme Brick
ACME BRICK Company received the Associate Member of the Year Award from the Dallas Home and Apartment Builders Association at their annual banquet. The award was presented because of Acme's "unfailing support of the builder organization and consistent excellence in products and service," according to DHABA executives.
Harold Melton, Acme's vice president of marketing and general salesmanager, accepted the award for Acme. He said it was "especially meaningful to be honored by a group of Acme's customers as the company begins its second century of service to the construction industry."
Users Want More
Brick Sample Facts
MASON CONTRACTOR Al Wendt recently surveyed 250 architects, owners/developers and contractors in a five county area of the Illinois and Indiana Masonry Institute, asking them to support the inclusion of more information on brick sample panels for use by the architect.
Wendt's respondents voted overwhelmingly in favor of supplying additional information-specifically initial rate of absorption, efflorescence and special cleaning provisions. Respondents also requested that information on saturation coefficients and compressive strengths be included with the panels.
One respondent stated that two recent latent defect issues, both involving brick, are related to initial rate of absorption factors. "It's clear that most architects don't understand the importance of matching mortar type to the IRA property of the brick... it's impossible to get satisfactory performance when the mortar is specified six months before the brick is selected."
Brick Institute of
Texas Restructures
THE BRICK Institute of Texas has revamped its structure to more closely align with the brick marketing council, becoming the Southwestern Brick Institute the first of the year. The SBI will expand to serve Oklahoma, Arkansas, Texas and Louisiana (west of the Mississippi).
Executive director Glen Duncan says a membership drive will be started in the new region. "Our goal is to become more promotional and less technical," says Duncan. "The board of directors will meet early in the year to develop plans."
Give A Hoot.
Don't Pollute.
Forest Service-USDA
Help In ADA Compliance
by NCSBCS and PVA
THE NATIONAL Conference of States on Building Codes and Standards, which represents state building regulatory interests, and the Paralyzed Veterans of America, a leading national disability organization, are working with the Department of Justice to assure voluntary compliance with the Americans with Disabilities Act (ADA).
Under Titles I and II of the ADA, publicly and privately owned commercial buildings must be made accessible. Currently, thirty-four states, representing 84 percent of the total U.S. population, have adopted and enforce statewide accessibility codes for commercial buildings. An additional twelve states enforce accessibility code for state owned or state funded buildings.
If states have their accessibility codes certified by DOJ as meeting or exceeding the provisions of the Act, then there will be a maximum level of "voluntary compliance."
LETTERS
More On Efflorescence
THE SEPTEMBER/OCTOBER issue of Masonry featured an article on efflorescence by Larry Gilbertson. While the article admirably explores its main contention that efflorescence is an indicator of moisture migration, there are several points concerning the nature of efflorescence which would benefit from further comment. I would like to offer the following in response to this article.
Contrary to Gilbertson's statement, there is no question that hydrated lime does contribute to efflorescence. It's also true, however, that hydrated lime added to mortar doesn't generally contribute to efflorescence. Although these statements appear to be contrary, they are not. They are, however, definitely confusing when taken at face value. The issues they touch upon are important enough to justify further examination.
Hydrated lime is responsible for the formation of a type of efflorescence which is chemically based on calcium carbonate. This comes as a consequence of the fact that hydrated lime lime is soluble in water. When concentrate is wet, hydrated lime is solubilized and transported in solution to the surface of the concrete. Once at the surface, the hydrated lime readily reacts with the air to form a white material known as calcium carbonate. This material remains on the surface as efflorescence. Gilbertson doesn't describe this type of efflorescence in his article.
Calcium carbonate based efflorescence is common, particularly with concrete masonry. It's also difficult to remove. Without intervention, it can take in excess of a year of normal rain exposure to wash efflorescence of this type away. With intervention, however, calcium carbonate based efflorescence can be removed with careful use of dilute acid washes. Although there are many other forms of white efflorescence, most are soluble in water and are quickly washed away by rain.
Although hydrated lime is responsible for efflorescence, hydrated lime added to mortar doesn't generally contribute to efflorescence. The reason for this is tied to solubility. Hydrated lime is present in all cured cement as a natural by-product of cement hydration. Because hydrated lime has only limited solubility in water, there is more than enough hydrated lime already present in cement that the addition of more hydrated lime will not increase the amount solubilized. Since only solubilized hydrated lime is of concern in causing efflorescence, adding hydrated lime to mortar doesn't generally contribute to efflorescence. Kevin Kuhl, Technical Service Coordinator, Grace Masonry Products, Milwaukee, Wisconsin.
A MAGAZINE is only as good as the input it receives from all kinds of reputable sources. One of the more important sources is comments from its readers. Readers are invited to express their constructive or critical opinions on any subject concerning masonry construction, or any factor affecting the masonry industry, including government, economics, legislation or whatever. We welcome all letters, and although all must be signed the writer may request that we withhold his name. Remember, this is the reader's column and we expect you to use it as such. Let's hear from you.