Latest DF post upgrade

[fisherking73]

Decided to eliminate or atleast slowdown the rot that will eventually happen to wood dragon fruit posts buried in ground.

[Coach62]

That's a PT post, right??  So instead of 30 years, it's now good for 50 years?  Man, you do plan ahead LOL.

Looks good, definitely not going to blow over.

I made mine out of 3" PVC pipe, wrapped in jute and chicken wire for the vines to have something to hold onto. 

[pineislander]

Just my opinion but embedding wood in concrete would be a mistake in at least two ways. Difference in thermal and water expansion, concrete doesn't expand much when wet, wood does swell, twist, and bend to exert considerable force, concrete is hard, brittle and cracks. Second, with the wood encased in concrete it cannot dry as it normally would in air and will encourage rot. I'm not sure what the reason would be for adding the wood, concrete has good compressive strength but posts generally use steel rebar which adds the tensile strength lacking in concrete. Hope it works out for you but as an engineer and mason I'd not do that.

[ricshaw]

Just my opinion but embedding wood in concrete would be a mistake in at least two ways. Difference in thermal and water expansion, concrete doesn't expand much when wet, wood does swell, twist, and bend to exert considerable force, concrete is hard, brittle and cracks. Second, with the wood encased in concrete it cannot dry as it normally would in air and will encourage rot. I'm not sure what the reason would be for adding the wood, concrete has good compressive strength but posts generally use steel rebar which adds the tensile strength lacking in concrete. Hope it works out for you but as an engineer and mason I'd not do that.

I agree.  I also wonder about the effect of lime leaching into the soil from fresh curing concrete.

[FamilyJ]

Thats my setup as probably seen

[fisherking73]

Great now second guessing my idea.

[Ulfr]

Hmm yeah you might have issues when they swell. That would be my main concern and would be an issue I think before rot ever comes into play.

Thats my setup as probably seen

How are you sticking those blocks together FamilyJ?

[FamilyJ]

Hmm yeah you might have issues when they swell. That would be my main concern and would be an issue I think before rot ever comes into play.

Thats my setup as probably seen

How are you sticking those blocks together FamilyJ?

Hmm i shouldn't have problems for swelling since i used spray foam, this is is sturdy where it survived hurricane Irma last year and maybe in California and AZ is one of the only places that use wood, since Hawaii and everywhere else uses cement so maybe not work for your climate but wood doesn't work in ours for very long so Philippians also use this method with cement, so not sure how that, and there are many post on internet on how this is put together, which as plant matures it in fact makes the structure that much more secure

[Ulfr]

Hmm i shouldn't have problems for swelling since i used spray foam, this is is sturdy where it survived hurricane Irma last year and maybe in California and AZ is one of the only places that use wood, since Hawaii and everywhere else uses cement so maybe not work for your climate but wood doesn't work in ours for very long so Philippians also use this method with cement, so not sure how that, and there are many post on internet on how this is put together, which as plant matures it in fact makes the structure that much more secure

That comment was aimed at you the original poster.
I quoted you to ask how the blocks were stuck together. Sorry for the confusion

[echinopora]

I don’t think you can go wrong with a concrete post. If you live in an area with termites/white ants then chances are your local farm store will have concrete fence posts, usually cost about 150% of the equivalent pt timber post. The ones at our farm store are pretensioned, so they have good resistance to lateral load, which brick won’t have. That can be important if you are a little slack on pruning like me, as df are negatively phototropic and will over grow to the shady side. That might topple a brick structure.

Here is one I did 2 weeks ago with 7’ pre tensioned posts. The top bar is dowelled and wired.



Here is an older one, the top bar is 2.4m long and just dowelled on, but I imagine the plant is pretty heavy.



 
If you were just running straight posts you could auger and cement a dozen in an afternoon even if you were hand mixing the cement, so saves time as well.

Rob

[pineislander]

Concrete fence posts are very rare in much of the USA. We are a disposable society, and we do have a lot of wood resources.
If you have a concrete floor and wall, it is possible to make a post with little more than one board, some plastic sheeting, rebar, sand, gravel, cement, and a shovel.

https://www.youtube.com/watch?v=iLvRt2eZMro

[echinopora]

Are concrete sleepers for retaining walls readily available there? A plain 8 footer is about $30 here, might be a bit of overkill but still a timesaver in the long run.

I don’t know what they charge for concrete post and rail in America but wouldn’t this be a sexy df setup.

http://www.concretefence.com/products/rail-fence/

Rob