pole building - Gravel size

[tinysparky]

I don't want this to be a discussion of concrete vs permacolumn vs gravel vs draypack concrete vs....whatever...

Question - For those of you who have - What is your recommended size of rock (with or without particulates) to back-fill a pole barn post?

Details - Recently got a building engineered and wet stamped...drawings came back with a concrete donut in the bottom with gravel around but the gravel type wasn't specified. 4' deep x 24" whole, 6"x6" post. Would love to hear your experience.

(Western WA)

 

[kbs2244]

The power company guys I have watched use washed stone from 1 to 3 inches in dia.

They tamp the hell out of it every 6 inches.

 

[chaosracing]

The best stuff to use since for some reason gravel was specified is called modified (if in PA) or some places call it crusher run or road base. It is made up of fines to whats called 3/4" stone. It packs really well (you will have to pack it in lifts) and once in place and packed, is almost as tough as concrete.

You will want to use a mixture like this because if you use a same size gravel (like 2B or 3/4") it does not lock together. The fines allow it to lock together.

 

[buddyboy]

whatever you use make sure it packs tight with no air space. clay is best, but if you are gonna use stone, make sure it's crushed with fines in it and pack it.

post needs air+water to rot so take away the air cause you'll never take away the moisture.

 

[lakeroadster]

Details - Recently got a building engineered and wet stamped...drawings came back with a concrete donut in the bottom with gravel around but the gravel type wasn't specified. 4' deep x 24" whole, 6"x6" post. Would love to hear your experience.

(Western WA)

Gravel all the way up to the surface or just near the bottom?

My barn used the pre-cast concrete pucks, and some poured footers too. The PE signed drawings did not specify gravel fill though. The contractor back filled with the existing material... the soil and rock that was removed during excavation.

Of course it is very arid here.

 

[tinysparky]

Got the answer -

There was a footnote from the engineer:

6" Concrete pad at 2500psi

5/8 - 3/4- gravel or crushed rock The contractor should ensure the gravel is saturated prior to compacting and is compacted every 6".

Going to rent an air tamper for $50 and a Diesel Air Compressor at $145. Tamper needs 45cfm at 90psi. (and a friend for pizza and rootbeer to run the beast all day...)

Thanks

 

[tinysparky]

whatever you use make sure it packs tight with no air space. clay is best, but if you are gonna use stone, make sure it's crushed with fines in it and pack it.

post needs air+water to rot so take away the air cause you'll never take away the moisture.

Good point -
I will be pouring a slab over the floor and post once compacted. Plus there is a 2' overhang and gutters.

 

[PWC Repair]

Around here we call it base run or 3/4 minus.

 

[hoppsxc140]

Skip the air tamper and use a gas or diesel powered jumping jack from the same rental place.

 

[PeterT]

Just throw in 6" of crusher run, and a 15 lb sledge hammer, tamp with the top of the sledge, another 6", more tamping with sledge head.