Foundations and Sills
Most historic barns were constructed using stone for their foundations. Early ground level barns were often built with single large stones at the corners and post locations, while some had rough dry-laid stone walls around their perimeter. A common problem with these foundations is the close proximity of the sill timbers to the soil. Very often the problem is made worse by the ground level around the barn being raised by the slow accumulation of sediment and manure. This condition inevitably causes the sills to deteriorate. Replacement normally is not difficult, unless the barn has had additions or major modifications.

It is common to find makeshift repairs done in barns that have suffered sill deterioration. One such "fix" is pouring concrete along the front edge of the drive bay (where the main barn doors are) or threshing floor allowing equipment access where the sill is missing. The unfortunate result is accelerated rot of the timbers that are in contact with the concrete due to moisture being trapped. The correct repair in this situation is to replace the sill with a rot resistant material such as white oak. Sill replacement is accomplished by "jacking and cribbing" the barn. The jacking is usually done with steel beams which are then cribbed up with stacks of wooden beams called "blocking". In the photo to the right, a ground barn is cribbed up and ready for sill and or foundation repair.