Pole Barn - Post?

[Beltzington]

Over the years I have found it much easier to plan to work rather than do the work so here is a question concerning placing a post or pole into the cold cold ground.

Having read many, many threads it seems the common recommendation is to place cement or crushed rock in the bottom of the hole before setting the post and back filling. Most of these instructions reference drainage as the reason to do this.

Considering water will seek level what possible advantage can this method offer. If the ground around the pole is wet the pole will be wet regardless of what it is resting on. I have missed the obvious before but this has me puzzled. TIA.

 

[Rustyiron]

Over the years I have found that is easier to think about than it is to either plan or do!
If you don't fasten the post to the concrete "foot" is does nothing for you unless you have some ground condition that might allow the post to "push" into the ground under a very heavy snow load. Uplift is a much bigger concern, and all that really takes is a few 12"-16" 2x6 nailed horiz. across your post below grade. An alternate is 3 or 4 pieces of rebar through drilled holes in the post. Usually the post will rot the worst at the dirt line, less below grade. If you can provide good drainage away from the bldg and post, with a little gravel at grade you should be ok. I don't trust the newer PT lumber, I prefer to laminate my posts together using 3 2x6 and not a 6x6. I have not seen a PT 2x anything that was ground contact rated on the little tag on the end of the board. I have used a precast conc. post on my last few projects.

 

[juandigital]

my code required me to have a 24 inch wide 5 inches thick concrete pad under each post. I ended up getting preformed cookies for this job. The inspector explained that its required so that the post wont "sink" over time. Talk with your inspector, after all, he is the guy you gotta please.

 

[Highbeam]

Having read many, many threads it seems the common recommendation is to place cement or crushed rock in the bottom of the hole before setting the post and back filling. Most of these instructions reference drainage as the reason to do this.

Considering water will seek level what possible advantage can this method offer. If the ground around the pole is wet the pole will be wet regardless of what it is resting on. I have missed the obvious before but this has me puzzled. TIA.

You're right, it has nothing to do with drainage. Ground water is ground water.

Gravel is easier to compact. When you dig a post hole for a building you might overexcavate on accident or you just want to level out the hole bottom. Use gravel for this because it is easy to get level and compacted. There are also no big rocks to deal with.

The concrete on the hole bottom is to spread out the load of the post over a bigger area so it isn't easily driven into the earth by the building load. It's a foundation of sorts.

 

[Dave5264]

my code required me to have a 24 inch wide 5 inches thick concrete pad under each post. I ended up getting preformed cookies for this job. The inspector explained that its required so that the post wont "sink" over time. Talk with your inspector, after all, he is the guy you gotta please.

Ditto for me, code was 24" augerd holes 4' 10" deep, 10" of concrete as a pad/footing under each 6x6 post to stop sinking. Each post has a 2x6 skirt nailed to the bottom to stop uplift.