Replies

1. 
   bldrbill | Sep 24, 2009 04:56am | #1

   White oak would not be my first choice for this.  The gate would probably last a good while, but fence posts just a few years in contact with the ground.  I use black locust for posts because they last many years in contact with the ground and sasafrass for gates because it's light and lasts a long time if it's not in the ground.

   Edit to add, if these woods don't grow where you live they will be hard to find.

   
   

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   Edited 9/23/2009 9:58 pm ET by bldrbill

1. 
   SteveSchoene | Sep 24, 2009 05:14am | #2

   White oak (heart wood) is fine for exterior use.  It will weather to an attractive grey and is rot resistant. (Red oak on the other hand is one of the worst for exterior applications.)  There are a few woods better for ground contact--though pressure treated really takes than honor for that these days. 

   Other rot resistant woods include teak and ipe.  Cedar, red wood and cypress weather OK but are soft and you need to be sure to use heart wood.  Old growth was even better.  Walnut is another good rot resistant wood. 

1. 
   bldrbill | Sep 24, 2009 06:19am | #3

   My experience with white oak as fence posts shows that they will last 10-15 years, and I have locust posts 25 years old and still good.  With the expense and hard labor involved in fence building, I want more life than white oak gives me.  I'm in AL where we often have damp soils, and maybe that helps them rot faster.  Osage orange is a good choice if you can find it.  I've seen osage orange posts actually sprout and grow when set in perpetually wet soil. 

    

    

1. 
   SteveSchoene | Sep 24, 2009 03:00pm | #4

   Black locuts and osage orange do make superior fence posts, but finding them isn't likely to be easy in most areas.  Pressure treated (with ground contact ratings) is likely to be the most durable available option for most of us, despite issues of attractiveness.  But for elements other than the posts white oak, and a number of other woods, will have a very long life. 

1. 
   spotcheck | Sep 25, 2009 03:49pm | #5

   FWIW - It is fairly common to find the builders of "pole buildings" use laminated posts, where the bottom of the post is PT, and the top is untreated.  The "bottom" PT part needs to be long enough for below-ground and then a little above ground.  "A little" is pretty vague, but if it was me, I'd have 4" above ground if it was in a lawn-type setting.  If it was to be landscaped with plants, etc, then I'd go higher - keep the untreated section in the open air.

   This lets you use any type of wood you want for aesthetics, but have a long-life on the below ground part.

   Example below.  The problems are (a) getting the dimension you want for the finished posts.  Using 2x4, you get a post that is 4-1/2" x 3-1/2", and (b) the time and expense to asemble the post.  You could use a solid untreated post, and cut away the notch to receive the PT.

   EDIT - I don't know of an adhesive that works on PT.  Need to use galvanized fasteners (lag screws would be my choice, but I'm big on over-kill.  Galv nails would work fine too).

    

   Edited 9/25/2009 8:54 am ET by Spotcheck