Hi,

Recent mention has been made about the efficacy of some timbers in service (Brungraber) and the multitude of tieing joints types (Sobon / Lewandoski) that can and are employed in timber-framed buildings.



I thought that I would share some of the hard realities of life (and death) of a timber-framed building with the timber-framing community.

The English tieing joint assembly has been employed thousands of time but eventually (some considerable time ago) this joint or more correctly the structure yielded causing the tieing joint assembly to move apart. The post top rotated outwards breaking the teazle tenon and breaking the cross brace pegs. In very simple terms A + B = C where the outer edge of the wall plate is not completely clear and the possibility exists that the wall plate has been replaced at some point since the shoulder of the lap dovetail seat is not completely evident.

An attempt has been made at some time in the past to strap this joint together using an old metal cart tyre which is the most frequently encountered method employed to strengthen this type of joint. It works. With the passage of time these straps have also become an architectural feature worthy of preservation.

I sometimes wonder if the complex detail calculations and analysis undertaken by north american timber-frame designers on timber frame joints are really worthwhile especially when an old cart tyre is a solution that can deal with a multitude of woes.

This building has now been standing for 689 years !

P.E.'s and anyone else please discuss

Ken Hume