Pressure Treated Wood For Trellis System?

[fifthhorsm]

your right about how bad steel or any other posts can look if leaning... thats why i use such long ones... with 10 foot you have to use a ladder to drive them in.... not likely to lean if 4 feet is in the ground... and if you want you can set them in concrete... you can't dig a 4 foot hole very easy but what i do is dig a hole as deep as i can about 2 1/2 feet then drive the post in and pour concrete around it...anyway you do it it's alot of work. but the effort you put into setting the posts will tell with time.
ppbart right about what type of treatment above ground or rated for contact... all types of treatment other than boric acid are toxic and can leach off into the soil. so that should be a concern. sirs is also right about caps they do make a big difference but even a cap is worthless if the bottom of the post rots away.... i think the biggest problem in how long a post lasts is soil drainage... i have heavy clay soil thats slow to drain and holds water underground... we only get rain a few months in winter so thru the growing season have to water... non of which is good for wood. in years past you could buy posts made of things like chestnut or black locust or split cedar heart wood... these woods last a life time but i doubt you'll find any now, certainly not at your local lowes. sometime look good at the quality of the wood used for pressure treatment it's mostly crap... most of it you couldn't sell as regular lumber it's so bad but now with building codes what they are we have to use pressure treated wood in some applications so regardless of the quality it's going to sell..... nothing like making a captive market and having the long arm of the law to back it up. i don't know about the newer composites for decking other than the cost.... have someone along to help pick you up when you faint.
mike

 

[Airplanedoc]

Another thing to look into is pouring the concrete and putting the metal deck brackets into the concrete. The the pressure treated stuff bolts onto that. It keeps the wood off the ground completely... Only thing is I don't know how much lateral weight they can hold that way, but the can hold huge decks up!

Those are only good for a vertical load situation, There is only a couple nails sometimes a lag screw holding the post to the footing so they are easily knocked over in a shear or lateral load situation

 

[closetwine]

Those are only good for a vertical load situation, There is only a couple nails sometimes a lag screw holding the post to the footing so they are easily knocked over in a shear or lateral load situation

Ok, I wasn't sure, but thought I'd throw it out there... Thanks for chiming in and clearing that up! I've never used them for anything myself, but have seen others use them....