A shelf or slab or stone, wood, or metal at the foot of a window or doorway.
The first time I heard "sill" mentioned, we were discussing a new door with Jack Crane. He thought that the odds were, it would need some attention before a new door could be installed. The first time Nate looked at the house, he agreed as he spotted a tell tale sign right away - the lower courses of clapboards were compressed vertically indicating settling yet the stone foundation looked intact.
Indeed, a substantial sill repair was needed as the old brick stairs that were built up against the house were in fact trapping water against the house and rotting the sill.
At this point, this was the third sill Nate and Darryn had repaired on our home. When they dug into this repair, they discovered that the first floor timber frame had already been replaced some time ago (from underneath). Luckily, whoever had done that repair had done a pristine job that made the integration of this repair straightforward.
The first repair was the peculiar sill under the kitchen window which was not particularly functional. Half of the kitchen actually rests in a structural bridge in the house between the original el that extended 16 feet off the back of the main house (and had a hip roof line), and a cape (which had a gable roof line) that had been relocated to the site and added at the end of the original el.
This photo shows the new, more functional sill installed. The relocated cape started at the joint in the roof and had the steeper roof pitch. The original el ended at the left of the opening in the above photo. There is superficial roof framing that hides the original hip roof of the el and results in the gable end at the joint. But you can still see the traces of the hip roof when standing there and looking closely.
When we installed the new french doors to the patio, luckily all we needed to replace was the sheathing beneath the door opening.
The sill on the adjacent wall needed to be replaced however. The patio was very much like the brick steps on the front of the house in that the non-porous material (rock) was trapping moisture against the house and rotting the sills.
Here is that same wall after the sill and boards have been replaced and a water table added.
This photograph explains why it is so important to pay attention to your sills. One does not want to install new windows, doors, or siding if the foundation that supports those things rests on something less than stable, and as you can see repairing them is not a trivial endeavor. We will continue to work to bring the grades next to the house down over time. Eight inches below the bottom of the sill is the typical recommendation to give them some breathing room.
In all, we've repaired five sills on our house.
She is officially sill strong.
By Mike and Catherine