Secrets of the Anglican Buttresses

Students of the 2008 course may remember St. Luke's Anglican Church at Coin du Banc. Like all the Anglican churches we saw in this locale, it has characteristic Gothic buttresses made of wood. Though real Gothic buttresses are stone, they certainly reinforce the Gothic style. This wooden design was the template for Anglican churches in the late-nineteenth-century in Gaspe cultural landscape, if I remember correctly.

So again, if I remember correctly, we were told that these buttresses are thought to be simply decoration. Now, I disagree.

At St. Lukes, the inner structure of the buttresses on the west side was exposed for restoration. I had uploaded this photo to my Facebook site and had a sudden revelation as I was reviewing a caption--that it was just decoration. As many times as I had looked at this photo, the function of the framing did not register in my mind till then. My epiphany contests the idea of "just decoration."

Look at the diagonal timber. The bottom end makes a "birdsmouth" joint into the end of the beam so it cannot slip out. The birdsmouth is an age-old structural joint. The top seems to pass into the wall. The beam probably spans across the to the other side, tying to the opposite buttress, tying the building together. They are heavy pieces--timbers, which are used for structure. Also notice that the buttresses fall midway between the windows and hit the wall at about the point of curve at the window. Is there anything to meet it on the interior?

Look at the location of the truss on the interior and the height on the wall where it ends. That is the spot where the buttress hits on the exterior.

The buttresses appear to function structurally after all, as a truss (a triangular arrangement of members that resist forces) dressed up as a buttress. A buttress in wood.

If all they needed was decoration, they could have done it with a lighter design of vertical studs.

What do you think? Decoration or structurally functional? This hypothesis could be tested with plan and section drawings, along with investigation of the connection between the buttress truss and the roof truss. But I think these churches would collapse without these wooden buttresses.