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I agree with Mike on the "masking of variations (due to inconsistency in firing) in the lighter glaze colors."

On the quality of the brick "it depends". We just did a project where the original white glazed brick was failing from poor detailing of the 1950's cornice stripping of a 1920's building on the Upper West Side. A previous project (by another architect and contractor) rebuilt one of 2 street facing parapets with matching brick in 2002. We were working on the other parapet last summer and the project extended thru this past winter. Over the course of the winter the glaze began to spall - the parapet was just 5 years old. First in little pin-holes then larger as the winter progressed. We probed the wall and noticed the same faulty details used in the 1950's had been incorporated in the parapet which was rebuilt in 2002. The faulty detail allowed terra cotta belt courses to be back-pitched towards the wall (this terra cotta was reused from the original 1920's construction). The water saturated the wall and the modern brick below failed. However, later in the year rebuilt building corners also began to spall too where there was no influence from the back pitched terra cotta. So, we identified the white glazed brick that was used, got test data from the manufacturer and discovered that the brick did not comply with Severe Weathering Criteria which is typically required in NYC. Admittedly the back pitching was not good but less than adequate bricks were also a big problem. Ultimately we added flashing over the terra cotta and replaced the spalling brick with better material. Hopefully this will not reoccur.

Eric Hammarberg, Assoc. AIA
Vice President
Thornton Tomasetti
51 Madison Avenue
New York, NY 10010
T 917.661.7800 F 917.661.7801
D 917.661.8160
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Co-op at 71st and Fifth Avenue, ca. 1960, is replacing its white glazed brick facade, due to the usual failures. In this case they have chosen ... white glazed brick.

question 1: why are there little raised black specks on the glaze? To make it look interesting, But not very.

question 2: is currently produced white glazed brick better than the 1960 version? It MAY be. Glazed brick wasn't well understood back then and is GENERALLY better understood now. The question is whether the current a/e specified and the manufacturer provided a GOOD brick which will not be overly water-absorbent and will therefore be frost resistant or were the failures due to maintenance? Not a maint issue. The old brick absorbed too much water, which got stuck behind the glaze, froze and spalled.

c Ralph

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