Replies

1. 
   sawdustdad | Apr 22, 2009 11:25pm | #1

   I would use locust for the posts and cedar for the overhead, if only since it's easier to work. Black locust is very dense, you will need to predrill for nails. The heart wood will last longer than the sap wood. As an example, I have black locust 5 x 5 fence posts that were set in soil with a concrete collar (gate posts) in 1981 that are still solid. Central Virginia, reddish clay soil. Line posts (3x5 or so) lasted 20 years before they had to be replaced. Some were still solid, some showed rot below grade.

   I've heard that black locust lasts one year longer than stone, but not forever. [&^)

    

2. 
   SLOSapo | Apr 23, 2009 06:21pm | #2

   If you use cedar posts, I'd recommend pouring concrete footings and attaching the posts to the footings with Simpson post bases. If you take this route, you'll need some diagonal braces to prevent racking.

   Also, if the cedar isn't dry, you'll want to use very substantial connections (like through-bolts) and lots of blocking to keep everything from warping.

3. 
   saschafer | Apr 23, 2009 06:39pm | #3

   I did some investigation into using black locust for posts a while back, and learned that while it usually has exceptional decay resistance (comparable to that of exotics like ipé and gonçalo alves), it is sometimes afflicted by sulfur fungus, which causes it to decay fairly rapidly.

   Finding that out kind of turned me off on using black locust in an application where it would be inconvenient or impossible to replace a rotten post.

   -Steve

    

1. 
   KeithNewton | Apr 24, 2009 06:36am | #5

   Steve, There is a fungus that attacks the pith of living BL trees, but doesn't affect the wood after it is dead. Are you sure you are not confusing this with something else?Could you share you source of information?

1. 
   saschafer | Apr 24, 2009 04:00pm | #6

   It was a few years ago, so I don't remember all of the details. My rather vague recollection is that it was in one of the Forest Products Laboratory publications, but I can't seem to find it again. According to what I have been able to find doing a Google search just now, sulfur fungus usually attacks live trees, but can also attack dead trees. (I don't know if a wooden post in the ground is sufficiently like a "dead tree" for a new infection to take hold.) But as I recall from what I had read before, the problem is that once the infection has started, it will continue (as long as the conditions are right, of course). So you could have a black locust post that seemed sound, but contained a trace of the fungus, and would therefore deteriorate fairly quickly.

   The bottom line in the publication was that black locust posts would normally last at least 25 years, but in cases of infection would decay in less than 10 years.

   -Steve

    

1. 
   Wolfman | Apr 24, 2009 09:52pm | #7

   Thank you all for your replies. I am still undecided and just remembered I could consider white oak also. Decisions, decisions..........

4. 
   stevo1952 | Apr 24, 2009 04:51am | #4

   Wolfman,
   I have used Black Locust for outdoor chairs and a shaving horse and have been very pleased. It works like oak or ash and is heavy, but I finished it with oil and it is a beautiful golden.

   
5. 
   WillGeorge | Apr 26, 2009 03:27pm | #8

   Jersey Shore folk..

   I would ask what wood like salt spray!

1. 
   Wolfman | Apr 27, 2009 10:59pm | #9

   None! Thats the problem. Its looking like Cedar would be the best choice, lighter, easier to mill. Lots of stainless steel hardware.