I am looking for some advice on repairing decayed post bottoms with all wood scarf joints. Most are only the bottom 16", on a few others the rot extends up into the girt connection. I have looked around and had some ideas, i.e. double bladed scarf. I have used this joint for sills, but to cut it on an existing vertical post does not seem very appealing. Any ideas out there?

How about cutting the post off square and use a splined connection. I've seen this repair used in an old barn where the posts rotted off. It looked like it had been done a long time before and was working. (except that the repaired bottoms were now starting to rot!)
Mark Surnoskie

Hello Brian:
repairs to your posts can be done in this way:
Use a half lap of about 20 inches in length, and then either bolt the connection or if you want to keep things authentic bore 4 --1.5 inch holes and attach using oak pins split from good straight grained oak sharpened. You should use a drawbore technique on the holes ie: bore the holes out of alignment about 1\4inch to pull the joint tight tightly together. also the holes should not be aligned with one another but slightly out of line for good workmanship.
NH

At the Cuvilly barn repair project, but on by the Guild, we learned how to cut a two blades scarf joint for post repairs. I took several photos of the process that I could forward them to you if you wish. But these posts were not attached to a standing structure. So we could roll them on our benches. However the instructors said that this was the common joint they used to fix post bottoms in standing buildings. I'm not sure what procedures they use to cut a repair joint on a standing post, but it can be done.
When we pegged our repairs we use straps and come a long to pull the joints up tight and then bored the holes straight through the joint. Although we did angle each of the three holes different from each other. One was pointing slightly up, one was pointed slightly down and the middle one was straight or perpendicular.
If you draw bore your holes as much as a 1/4" as mentioned you could put excessive stress on the pegs depending on the size, type of wood, and amount of relish. I was taught that 1/8" was standard, but to each there own. Not saying 1/4" is wrong, but it depends on site specific situations and conditions. Good luck with your project. Jim

I have to agree with Jim, that 1/4" seems a bit excessive. We find 1/8" typical in old hardwood frames and even less in softwood. The big problem I have seen is actual "splitting" of the timber through the peg hole.

One unmentioned issue in the discussion is scarf joint location. Remember that the moment increases with the length of post cut off. The forces you are resisting in a short repair are primarily compression and shear. As you move up the post bending comes into play.

Bolted scarf joints work much better than pegged (bet you never thought you would here ME say that!) when bending forces are significant. If a solid wood repair is needed, try "under-squinting" or "cogging" the abutments. Cogged abutments are shown on the post repairs at the Cuvilly workshop page on this website. An exagerated version of this joint is the face halved scarf with bladed abutments. A little harder to cut but better for pegging.

A good reference for scarf joints is the illustrated glossary in R.W.Brunskill's "timber Building in Brittain".

Good luck with you repairs and remember to support the frame well. Safe work is good work.

Rudy R. Christian

We deal with this issue on a regular basis and have found the bladed wedged scarf a great repair. We have done this repeatedly on standing barns with great success (sometimes we don't peg it until we put pressure back on the post). Another note is orientation, we try to put the scarf opposing lateral forces. We have a photo of one in action on a standing barn that Simon Gnehm did for us under extreme pressure, check our website at www.trilliumdell.com and look under historic retoration then restoration process.

All,

I appreciate the advice you all have given. I like the idea of the repair at the Cuvilly barn. Jim, I sent you an email taking you up on your offer for the close-up shots. I noticed in the Trillium Dell pictures that the tie beam connection has a scarf as well. Is this the same style as the post?

Brian Mulcahy

No, the tie-beams all have simple under squinted scarfs.