The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: Woodman12 on August 02, 2012, 03:00:45 PM

Title: Strength loss of green post
Post by: Woodman12 on August 02, 2012, 03:00:45 PM
Quick question.  If i take a 10" diameter post directly off of the mill and put inside a house.  It will be load bearing.  I know that checking will occur, but will there be a significant loss of strength.  Is it possible to do this or should this idea be tossed out of the door.
Title: Re: Strength loss of green post
Post by: Al_Smith on August 02, 2012, 03:09:46 PM
Well they took basically green oak and built those huge dairy barns about 100 years ago and loaded the mows full of hay if that tells you anything .If they kept a good roof on them they're still standing .If not they all fell down years ago .
Title: Re: Strength loss of green post
Post by: Jim_Rogers on August 02, 2012, 03:24:56 PM
Quote from: Woodman12 on August 02, 2012, 03:00:45 PM
Quick question.  If i take a 10" diameter post directly off of the mill and put inside a house.  It will be load bearing.  I know that checking will occur, but will there be a significant loss of strength.  Is it possible to do this or should this idea be tossed out of the door.

You will not loose any strength from the checks as they only go from to surface to the pith of the tree. And not all the way through which may let the post split in half.

The loss in strength is that a green post is not as strong as a dry post. Water in the green post will dry out and it will become stronger as it dries.

So if the size of your post is marginal to the load you want it to carry then you may want to either up-size the post a little, choose a stronger wood, or wait a year or two until it drys out some.

Jim Rogers
Title: Re: Strength loss of green post
Post by: Woodman12 on August 02, 2012, 06:13:09 PM
Thanks for your input Jim.  That is what I needed to hear.
Title: Re: Strength loss of green post
Post by: Satamax on August 05, 2012, 01:44:26 AM
Woodman12.

If i may add, an oak post, 10"x10", 10' tall; can bear 30 metric tons. And iirc, that's with a safety margin of 6. So it takes 6 times that to colapse.

Take 83% of that for larch or slow growth pine, 66% for cheap fast growing pines.
Title: Re: Strength loss of green post
Post by: canopy on August 08, 2012, 07:55:20 PM
Structural calculations are usually based on clear wood. Brace pockets and other joinery between the base and loaded surface need subtracted out. Grade of wood also needs considered.