[Jason17068]

Can anyone help if I'm reading this correct? I've attached a picture of what's required. If I'm using 6x6 posts. How big of concrete tubes do I need? 16 inch diameter at 30 inches deep right?

It says that the footers most be 8 inches larger then the post I'm using. (6+8=14) but they don't make 14 inch. So i need 16 inch tubes. Right?

The contractor worded the footings like this "
All in ground posts to be 6x6 #2 grade, Arsenic free pressure treated wood
All in ground posts to be set on 8? thick footer in 30? deep hole "

Shouldn't the thickness be 30 inches?
Or am I totally wrong....

 

[dsec123]

hi! i can't seem to open the attachment and can only see a small part of it, but i think for footings you use a bigfoot form (this black plastic cone-shaped thing that goes in the bottom of the hole) and that would be min. 14" diameter (i think they come in that size). then on top of the bigfoot you put your sonotube, which can probably be smaller in diameter.

 

[Oso954]

All in ground posts to be 6x6 #2 grade, Arsenic free pressure treated wood
All in ground posts to be set on 8? thick footer in 30? deep hole "

Sounds to me like he is planning to pour an 8 inch thick footer (width not specified) and set the post on it, or in it, below ground level.

Something like this.

 

[dsec123]

cool! i haven't seen that done before up here. great picture! even with the gravel, wouldn't the post rot a lot faster than if it was above grade?

 

[Jason17068]

Thanks.

I think I am going to ask him to have 30 inches of concrete instead. I don't want to deal with any rot.

Thanks

 

[dsec123]

the detail i am more familiar with would be to pour your footing, then a thinner concrete tube that goes 8" above grade, and then put the 4x4 post on top of that using an adjustable post base as a saddle for the 4x4. that way the post is above grade, you use less concrete, the post still won't move because the footing is below frost (which is like 5' here, not 30"!) and if for some reason there is slight movement, the post base can be adjusted to re-level things.

 

[Thurman]

"dsec123": I doubt that the post would ever rot even in your area. The post is embedded in concrete up to the frost line in your area and the gravel helps water to run into the soil all the way down to the frost line/concrete level.

 

[dsec123]

what is the advantage to having the post buried, though? is it cheaper to fill the hole with crushed stone/buying a longer post, instead of just having a sonotube that goes above grade?