The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: shane77m on September 01, 2014, 01:41:38 PM

Title: Center post scarf
Post by: shane77m on September 01, 2014, 01:41:38 PM
I have been kicking around some designs on a house I would like to build. Is it acceptable to put a splice in a center post? If so, it would make it a lot easier to handle a shorter log than a 24 footer. Thanks for any assistance.

(https://forestryforum.com/gallery/albums/userpics/36816/center_post.jpg)
Title: Re: Center post scarf
Post by: Jim_Rogers on September 01, 2014, 08:21:07 PM
Yes, a vertical scarf is ok, as long as it is cut correctly.
That means 4 times the width in over lap.
And all parts of the end grains of both pieces have to completely bear on their mating pieces. If they don't then the fibers will crush until they do. This may mean that the post would get shorter a bit until all surfaces bear the weight of the structure above.

Jim Rogers
Title: Re: Center post scarf
Post by: shane77m on September 01, 2014, 08:42:38 PM
Thanks  Jim. That is the answer I was hoping for. I have the means to cut a 24' long post but moving the log around to get it might be more than I can handle. Not to mention the troubles that would come with raising a 20 plus foot post.

I guess I need to start practicing my scarf joints now and maybe by the time I am ready to start on the house I will be able to cut them decently.

Title: Re: Center post scarf
Post by: LeeB on September 02, 2014, 03:11:46 AM
How would you cut a verticle scarf? would it be tha same as a horizontal scarf?
Title: Re: Center post scarf
Post by: Jim_Rogers on September 02, 2014, 04:32:35 PM
Quote from: LeeB on September 02, 2014, 03:11:46 AM
How would you cut a verticle scarf? would it be tha same as a horizontal scarf?

The most common vertical scarf is a bladed scarf joint:



 (https://forestryforum.com/gallery/albums/userpics/10095/First_post_extension.JPG)

I have written an eBook about how to do this. And the last time I did this I video taped the entire process from end to end.
The video is three hours long cut into 38 short sections. It comes on two DVD discs due to the size of the videos.

I have this available. If you send me an email via the regular email system to jrsawmill (AT) verizon (dot) net, I'll give you the details on purchasing either the eBook or the videos.
5% to FF if you mention it to me in the email.

You can see some of the scarf joint in my safety video on YouTube. Search for JimRogers117 on YouTube and you should be able to find it.

Jim Rogers
Title: Re: Center post scarf
Post by: razor on September 03, 2014, 02:52:44 PM
 

 (https://forestryforum.com/gallery/albums/userpics/32809/IMG_0125.JPG) 

 (https://forestryforum.com/gallery/albums/userpics/32809/IMG_0129.JPG)
Here is a scarf I invented some time ago. At least I THINK I invented it based on that I've not seen another. I call it the "Razorblade", clever eh? Probably wouldn't use it in a post though.
It fared well in the joint busting machine back in Saratoga. Came in second place if i recall. Still have the ribbon ;D
Title: Re: Center post scarf
Post by: D L Bahler on September 03, 2014, 06:53:38 PM
On the European Continent, you often see spliced posts. Many buildings of any age have spliced posts, because they have been repaired or modified at some point in their life.

The most common vertical splice I see is a simple necked splice, where one (the lower) timber has a very long tenon and the other (the upper) has a 'neck' or a forked tenon. This is then reinforced with many pegs.

Another approach, you could just interrupt the post at the tie beam. Have the tie beam land atop the lower post, then have an upper ridge post land atop the tie beam. This is a very common solution, at least in Switzerland, to not having suitably long timbers -or not wanting to handle such long timbers.
Title: Re: Center post scarf
Post by: BCsaw on September 03, 2014, 10:04:43 PM
Very interesting joint Razor. I like the fact that it has been "tested".