Grand Portage Sill Repair

The Great Hall at Grand Portage National Monument.

While rebuilding the bulkhead, the maintenance crew discovered some rot in the sill behind it.

The historically accurate lack of gutters, a small gap between sill and bulkhead as well as being on the north side of the building all have contributed to the decay. Additionally the scarf joint provided a perfect entry for the moisture.

 Two scenarios were discussed:

1. Support the walls & floor and replace the full 12×16″ sill timber crossing over the bulk head opening. Or

2. Determine the extent of the rot and if the timber is healthy enough, replace the outside four inches of the sill timber bridging the bulkhead opening and covering over the scarf joint.

 
 An initial exploration luckily confirmed that the rot was very local.

I removed a 4″ deep slice off of the front of the sill timber in the hopes of not having to chase the rot too far into and along the timber.

A second deeper recess found plenty of healthy wood.

So we opted for option 2.

A few weeks later…

A combination of drilling…

and chainsawing…

removes the bulk.

The joint to the right and the left mimic the scarfs on the other sill timbers. Much time is spent getting the surface flat and straight.

The replacement timber gets hewn on the surface that shows.

Then the scarfs get laid out on the back.

A quick bit of joinery cutting.

Beautiful texture.

Ready to go in.

It fits on the second time!

(Notice the handle of the big hammer)

The WoodGuard treatment brushed on the inside of the joint is squeezed out …

…by a wonderfully tight fit.

Pleasing.