by John Carter

Created on: October 22, 2008   Last Updated: May 15, 2009

How to use Pinned Timber Construction

A long time ago, before nails came into common use most houses and barns were made from 8 x 8 inch timbers held together with wooden pins. This was an extremely good type of construction, and anyone who has to take down one of these old structures knows that a chainsaw is in order. Using a chainsaw is really overkill and greatly diminishes the value of the timbers.

The colonists were a clever lot when it came to making anything whether it is a house or a barn. Most of the builders in those days were unemployed shipwrights, and took their shipbuilding skills with them whenever they were building anything else. One of these skills was using wooden pins to join timbers together.

The use of wooden pins in joinery goes back to ancient times, and has remained in use to the present day. The reason for this is because this is one of the strongest methods of joining two timbers together either straight or at right angles. This is accomplished using a mortise and tenon type of construction. This is by cutting one beam so it has one piece of wood sticking out of the middle of the beam. The other beam has a corresponding notch cut out of the center beam. Two small holes are bored across the mortise about an inch in diameter. The beam having the matching tenon is also bored, but this boring is slightly out of line with the holes in the mortise.

The framework was usually made out of chestnut beams commonly 8 inches square, the mortise and tenon are eight inches deep. The pin is really the important piece of this combination. It was usually made out of a green piece of elm that bends quite easily when it is green. One end of this pin is beveled so that it will slip into the holes that were bored earlier. The reason for the slight offset holes is because this caused the pin to be slightly bent in the process of being driven home. The outside piece of the pin is cut off flush with the outside of the beam. Usually the piece of pin on the inside of the structure was left as it was. This is an extremely strong type of construction, and it is virtually impossible to take apart without carefully considering the job.

The old time builders sure knew what they were doing; when they put something together it stayed. On the other hand they also knew how to take something apart they had built. All it takes is a little thought and imagination. The first thing they did after uncovering the joints was to take a small auger and bore a hole into the center of the pin just deep enough to reach the tenon. This they left alone for the moment; removing this part of the pin they could do at their leisure. The two outside ends of the pin were another matter though. This had to be removed with as little damage as possible. This was done with a small chisel, curved if possible or available. Chisel out the remnants of the pin and remove the mortise from the tenon. The portion in the tenon can then be knocked out easily.

Learn more about this author, John Carter.
Click here to send this author comments or questions.