The problem at hand was that both doors had sagged downward and were binding on the threshold. A lot of force was needed to get them closed, and as a result the doors were severely racked on a twice daily basis as the building was opened and closed. Constructed of two layers of vertical barn boards nailed (with square nails) to a plywood core, the doors had the structural integrity of a fish's tail and made a similar motion as they moved. The boards had split exactly four feet out from the hinges. Since the doors are five feet wide, and a sheet of plywood is only four, there was a vertical seam in the plywood at this point. This weak point also corresponded to the drip line of the roof:
Here I've removed the exterior boards and you can see the awesome fungus growing on the tar paper that covers the doors' plywood core:
You're probably thinking, "Hang on a minute, what are modern materials like plywood and tar paper doing on such an old building???"
The Weaving Shed was built in 1955, but it looks much older because it was constructed of old materials the Museum crew salvaged from other structures in the region, leftover parts from other projects, and/or materials that were purchased specifically because they were old and unique (We still have stockpiles of wide barn boards, bricks, square nails, roofing slates, figured hardwoods, etc.) We can only speculate as to the exact time period that this building was intended to represent, but at first glance it looks like it's from the early 19th century. Closer inspection reveals some very contradictory clues...more on that later.
In order to replace the rotten plywood I had to completely disassemble the door. I decided to take the opportunity to make a few design changes. I also made the new plywood core from two pieces, but oriented the seam horizontally. This way the two layers of barn boards would act as battens to hold the door together. The cracked inner sheathing board was 17-inches wide. To get a replacement I dug around in the carpenter shop attic until I got one I liked, ripped it to width and cut it to length (Yes, it was too wide at 18.5 inches!) I laid out the interior boards on my saw horses with the whitewashed inner faces down and glued and screwed the new plywood to them with construction adhesive and short decking screws:
Fixing such damage is only a temporary repair unless the source of the problem is identified and addressed. Therefore I had to do something about the water coming off that roof. There wasn't enough room for a gutter above the door, so I made a sort of inverted drip edge from a sheet of copper with a V-shaped channel on one edge. To install it I removed the first three courses of slate from the roof:
Special thanks to the Museum visitor who stopped to watch me work and ask whether they had Liquid Nails in 1850!