Monday, October 7, 2013

Arch # 3


The Jack Arch doesn't have a traditional 'arch' shape at all. It's flat. While the Jack Arch requires more mass surrounding the opening to stop any spreading, it is still amazing to see tons of stone suspended in air this way. I took this photo of this stone house with the Jack Arch windows still in tact after all the wooden frames were gone. Sometimes we imagine it's the wood or steel lintels that keeps the stonework up. Not so. 

I have never built a dry stone Jack Arch. I wonder if anyone has?

4 comments:

  1. Have you seen the Wikipedia entry for "jack arch"? In it there is a photo of a crypt roof at a monastery in Turkey near Mardin, that takes my conception of the potential for the use of the jack arch to a whole new level. Amazing!

    ReplyDelete
  2. Yes that is an amazing roof! No hint of a curve in the ceiling. The side walls must be very thick, or perhaps the whole structure is buried under the ground.

    ReplyDelete
  3. The Rockport fireplace had one.

    ReplyDelete
  4. scrub that thought... it had enough camber to be considered a segmental arch.

    ReplyDelete