Draw pegging explained

 

This is a brief description of what is meant by ‘draw pegging’…

This technique is well practiced in other carpentry and joinery trades, particularly when working with green timber. ‘Green’ simply means fresh cut and will have a high moisture content. Green timber will slowly dry and will shrink (approx 10%).

The mortice and tenon joint is typically held together with a timber peg, in our case we only use hand made tapered drawn pegs (that’s another few pages of text we’ll leave out in this description!). When the mortice (hole receiving tenon) is cut, a hole is also drilled through the edge of the timber aligning with this mortice. One, two or more holes are drilled to take the pegs holding the joint together. Mortice and tenon…

DrawPegging

In the workshop, the joint is fitted up without a hole in the tenon. When the joints are tight to a satisfactory level, the positions of the peg holes are marked with a special tool. They are then taken apart and the holes are drilled in the tenon with and off-set (draw) of a few mm towards the shoulder of the joint (away from the end of the tenon). This process is repeated for all the joints within a frame before being taken to site and assembled.

On assembly, the timbers are brought together, each individual joint marked unique to it’s position within the frame. The joint should fit snugly along the shoulder line. The following shows a fraction of a gap…

DrawPegging2

The following shows how this joint looks in section, with a peg ready to be driven in.

DrawPegging3

When the peg is driven in, the off-set in the mortice hole to tenon hole pulls the shoulder of the tenon to the face of the mortice, creating a very tight and solid connection. The green pegs are very strong and will bend around this off-set.

DrawPegging4

The the peg will be under an enormous amount of shear tension and subsequently, as the timbers shrink, with continue to keep the joint tightly together.

This process is more time consuming but delivers significantly better results than just drilling through once the joint is fitted on site.