January 2016

Timing Is Everything

by Don Friedman on January 29, 2016

Marieta pointed out yesterday that as long as I’m talking about crack monitors, I need to discuss their biggest failing: they depend on us to be installed and reviewed.


Notice how the crack is much wider than the distance shown on the monitor? If the crack monitors are installed after a severe event (in this case, movement from adjacent construction) then they may well she no movement or, as here, very little. That’s not meaningless: the issue of whether movement is ongoing or a one-time event is a serious one and data that addresses it is useful. It’s just not as useful as data that records all of the movement.

Failure Portrait: Bad Neighbors, Broken Mortar

January 28, 2016

Paint does almost as good a job showing movement as does plaster. Since the top of the building isn’t moving up, we know that we have movement of the bottom of the wall down, and that the movement is worse on the right than the left. In this case, there was no search for the […]

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2.5mm X, 0.5mm Y

January 27, 2016

Uh oh. That’s a non-negligible amount of movement since the crack monitor was installed. The surface itself is gypsum board – the thin filaments visible at the crack are joint tape – but the movement is structural, imposed from outside and made visible by the brittle finishes. This type of crack monitor is as low-tech […]

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Best for NYC: Other Companies

January 26, 2016

It is, honestly, pretty easy to address environmental issues in white-collar businesses. The actual process of our work doesn’t inherently use resources or create much waste. It’s much more impressive when manufacturing businesses can make their work environmentally friendly. Which brings me to Riva Precision Manufacturing, a company competing in the Best for NYC Challenge. […]

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Made Visible

January 26, 2016

Plaster interior finishes are a large topic of interest in historic preservation work. But, as an engineer, I’m not usually involved with that work. On the other hand, plaster is of great use in engineering investigations as a building-wide diagnostic aid. The wall on the right is plaster finish over brick, and is structural supporting […]

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Before Gyp Board

January 25, 2016

The picture below is in a fairly typical “pre-war” apartment house in Manhattan, after interior demolition has been completed for an apartment renovation. The building has a steel frame, concrete floor slabs, and a brick curtain wall. (Two concrete-encased steel beams are visible at the top of the photo.) The partitions shown are a fire […]

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Bannerman’s Castle – Less Obscure

January 22, 2016

Another Atlas Obscura mention of one of our project sites is Bannerman’s Castle, an abandoned arsenal on an island in the Hudson River. We completed stabilization of Mr. Bannerman’s house several years ago, and last year completed the first phase of stabilization for the main arsenal building. Our shoring looks quite spindly but it’s enough, working with […]

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Not So Obscure

January 21, 2016

Atlas Obscura is “the definitive guide to the world’s wondrous and curious places.” It’s effectively a smaller Wikipedia devoted to exploring the strange. I find the website to be irresistible and, inevitably, I started looking through it for buildings I know. In addition to a bunch of buildings and sites I know from daily life […]

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Historic Structural Detail: Not Very New York-y

January 20, 2016

American construction in the last third of the nineteenth century, particularly after the Chicago and Boston fires, was a search for better passive fire protection. One method that was developed and is effective, but is rarely seen in NYC, is heavy-timber construction. This is not simply the use of large-dimension timbers in a building’s framing, […]

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Best for NYC: Government Involvement

January 19, 2016

I previously mentioned the involvement of various city agencies in the Best for NYC Challenge. One agency I didn’t mention then was the NYC Department of Small Business Services. Small businesses, and I’m obviously speaking from personal experience, have a more difficult time with initiatives like the Challenge or becoming a B Corp because they have […]

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