Historic New Structural Detail

by Don Friedman on September 19, 2017

Even though construction is still in progress – note the blue tarps and the chain fall – that is a beautiful sight that very few people will ever see. That is the inside of a newly-constructed onion dome.

The old dome and cupola, which formed the steeple of St. Vladimir Ukrainian Catholic Church in
Elizabeth, New Jersey, was damaged in a wind storm in April last year. The church tower is brick, but the cupola and dome were wood and no longer in good condition. After an investigation and review of the various options, we ended up designing a replacement for the wood structure of the dome proper. The picture above shows all that beautiful new wood framing to create the onion-dome geometry. You can’t see the tie-downs which were our addition to the original design and will hopefully give Dome Version 2 a longer life than the original.

A problem we face again and again in church restoration projects is that the original structures of the long-span roofs and towers don’t meet current code. In general they have performed well (or at least well enough) but once they start to weather the problems quickly multiply. If the wood has rotted we can’t design a repair to be spliced in because the truss chords or spire ribs aren’t strong enough according to modern analysis. The connections, particularly those joints specific to large-timber construction such as birds-mouth connections, can’t be analyzed. We’re fine with leaving the old structures in place, but we can’t design repairs or alterations for something we can’t analyze. We usually end up simply reinforcing the existing wood to make it possible to work; at St. Vladimir’s the only real option was reconstruction. Our design followed the old as much as possible and the contractor, the Imhoff Company, did a nice job building the new dome.

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