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gcrank1
Member
# Posted: 26 Jan 2021 12:36 - Edited by: gcrank1
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Will, I dont have pics.
It was built 10 mi. north of Portage,Wi in the sand and gravel country; basically was on a high glacial moraine hilltop with woods. A million dollar view of the Wisconsin River valley looking toward the Baraboo Bluffs and Devils Lake.
I tell you true, that silo block set up I had originally intended for a 12x12 with a simple shed roof, then morphed to a 12x16 but I had enough salvaged wood that it turned into a 12x24. Then with a 12x12 stand up loft. Way more structure than I had thought!
I wondered over time how it would hold up but it did fine and as of my last look last Sept when I turned over the keys it looks like it can go another 37years. The stuff I see here, both contemplated and done, is better. For sure and certain ya build from the bottom up so make it good, maybe overkill a bit, but I do wonder about doing some of these for a shed to big shed sized structure to the same 'requirements' as a full size house. If ya gotta do that it is how it is, but since your BI seems to be reasonable to work with and says 'pads' are ok for the structure you have shown her I'd be on that in a WI minute!
Btw, those 10x30x2 silo blocks are Heavy, one is all I want to haul at a time (just hauled 10 from the hill cabin to the new one last fall). Ive been using them for decades after we used em for decades at the farm for all kinds of things. At 30 some % bigger footprint than the 14x14x4 pads Id guess they are about the same weight/awkwardness to manipulate.
Using the 6x6 pt posts keep the 'high side' of the grade to joist over 12"(?) as prev mentioned to not have to use pt joists or floor box.

Nate R
Member
# Posted: 26 Jan 2021 15:25
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If you're going to go that route, consider at list digging away the mineral soil until you get to the sandy layer. Maybe put some gravel on the sand under the pads.

That should give you a well drained base. Not really subject to frost heave then, and no expansive soil underneath....really shouldn't go anywhere. I know of a couple sheds nearby sitting on cinder block on the sand. Fine since 1981 for one, the other since 2002 maybe?

NorthRick
Member
# Posted: 26 Jan 2021 16:43 - Edited by: NorthRick
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Quoting: WILL1E
With the sand i have, i don't know that creating a bell bottom would be an option.


That's your answer. Sandy soil that won't hold together drains well. Do what the inspector suggested and just go a foot deep with 2'x2' footers. Plan your cabin to have a generous overhang on the roof and make sure the ground surface around the cabin drains water away from the cabin.

You need 3 things to be present for frost to cause a problem.

1) Below freezing temperatures.
2) Water
3) Frost susceptible soils. These are soils with a lot of fines - silt and clay.

Eliminate one of these and you won't get frost jacking or heave.

NorthRick
Member
# Posted: 26 Jan 2021 16:44
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What Nate said in the post before mine.

gcrank1
Member
# Posted: 26 Jan 2021 17:08
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Fwiw, Im in agreement with those posts too.
Looks like you could be ready to make a plan

WILL1E
Member
# Posted: 27 Jan 2021 08:36
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Thanks fellas!

Based on this post and my other regarding the elevated platform and that 16' span, doing precast pads could save me alot of $$$. For a 16x24 i would be looking at 12 columns around $100ea plus alotta digging.

FWIW, the BI did come back and say that if i did those 24" cone forms 4' down with a 10" sonotube coming to the surface she would approve that as an option.

gcrank1
Member
# Posted: 27 Jan 2021 10:02 - Edited by: gcrank1
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So, she said 14x14x4" pads would be ok or 24" cone forms 4' downwith topped with a 10" sonotube.
Ummm, leme think.
Fwiw, my current 16x24 one story, one room, rough built is essentially a pole building 'style' started with 12 posts in the ground. He didnt use pt posts either.
I would have much preferred it had been built on 12 14x14x4 pads. At some point I could start digging access and block it up to cut off each post and do a pad set; but at 68.....

WILL1E
Member
# Posted: 27 Jan 2021 11:12
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So if I do precast pads with PT 6x6 post going to my built up beams, should the post be mechanically fastened to the precast pads? Common sense tells me yes, but then i feel like it they should be allowed to move to some degree.

Thoughts?

WILL1E
Member
# Posted: 27 Jan 2021 12:21
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Quoting: Nate R
Maybe put some gravel on the sand under the pads.
Would you only do this for precast pads?

Only reason i ask is because if i decided to "upgrade" to larger pads they get pretty heavy and difficult to move. So i was thinking maybe build 2'x2' boxes that are 1' tall and pouring concrete on site.

I know i'm all over the place. Trying to find a middle ground or Option C which is in between:
Option A = a ton of digging, alot of $$$ but very stout
Option B = little to no digging, relatively cheap but higher risk of movement

gcrank1
Member
# Posted: 27 Jan 2021 12:48
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Imo, but with a money back return of what you pay for it if not 100% satisfied
If the BI does not require fastening the posts but is Ok with you doing so, and you would feel better doing so, do it.
But if you think it is going to keep it from blowing away in a tornado, it wont.
I didnt, my hill cabin never moved that I could tell and we had some big winds in 37 years; no direct hit tornado's though.
YMMV

Nate R
Member
# Posted: 27 Jan 2021 13:30
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Quoting: WILL1E
Quoting: Nate R
Maybe put some gravel on the sand under the pads.
Would you only do this for precast pads?


Yeah, my thinking with the gravel was just to bring the pads back up to ground level. At the same time, sometimes people DO put gravel under footings and such just to promote drainage and as a bit of a capillary break. Not sure if I'd do that or not under a larger footing.

Those larger pads are interesting. More load spread, thicker. But yeah, 160 lbs.

I do like the option C you're talking about, if BI approves, I think realistically, it'd be fine for a LONG time in the local soils.

WILL1E
Member
# Posted: 27 Jan 2021 13:38
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Quoting: gcrank1
If the BI does not require fastening the posts but is Ok with you doing so, and you would feel better doing so, do it.
But if you think it is going to keep it from blowing away in a tornado, it wont.


Not worried about tornados...that's what i've got insurance for My thoughts on brackets between post and pad was purely for stability and to prevent rocking. It takes minimal force pushing at the top of a 6x6 post to get it to rock...but the force to get a 6x6 post that's bolted to a 20"+ precast concrete pad would be much higher because of the surface area of the concrete.

gcrank1
Member
# Posted: 27 Jan 2021 13:44
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One post rock, yeah, 12 posts with the whole weight of whatchabuild on top, I dont think so.

Brettny
Member
# Posted: 27 Jan 2021 14:59
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Concrete epoxy is really really tough stuff. I put some about 3/8 x 1" x 4" on a piece of cardboard and could not break it in half. The stuff is about $20 a cawlk tube. You could glue deck blocks to the 20" cookies.

I haven't really found a 6x6 post base that can be attached to dry concrete that has any real lateral strength.

WILL1E
Member
# Posted: 27 Jan 2021 15:50 - Edited by: WILL1E
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Simpson has these for 6x6's.

Notation #6 below the load table says the bracket doesn't prevent rotation. However they don't spec anything anywhere about lateral specs.

Nate R
Member
# Posted: 27 Jan 2021 16:14
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Quoting: WILL1E
Simpson has these for 6x6's.

As an aside, I found that these were cheaper for me:
URL

Brettny
Member
# Posted: 27 Jan 2021 17:08
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Both arnt galvanized so I wouldnt use them for a foundation.

gcrank1
Member
# Posted: 27 Jan 2021 17:18
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Think I recall reading someone had sunk an L shaped re-bar into the wet 'crete with a goodly amount standing out and drilled the post to slide over it.
But you have to do your own mix & pour rather than precast.
I cant help but think about half the small buildings on the family farm. The barn had been built in 1897 and a couple of those sheds looked older. We moved there in 1960 so thats 63 years after the barn build and more than that for those sheds. One was a two story granary, all sat on dry stacked fieldstone 'piers'. I remember as a kid being there when my dad jacked some spots up and added a shim here and there one time. Over the years all but one were taken down as the place morphed and that last one is still there being used.
So, maybe....dont overthink this?

Nate R
Member
# Posted: 28 Jan 2021 08:14
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Quoting: Brettny
Both arnt galvanized so I wouldnt use them for a foundation.


Good point!

WILL1E
Member
# Posted: 28 Jan 2021 09:00
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I could just get some galvanized L brackets and attach them to the post and concrete on each side of the 6x6

gcrank1
Member
# Posted: 28 Jan 2021 10:00
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Not sayin dont do it, just thinkin with me fingertips....
What are they really gonna do?
Keep it from rattling off the pads in an earthquake?
Keep it on the pads in a big, hard blow?
Make it harder to shift it back on the pads IF it moved?

WILL1E
Member
# Posted: 28 Jan 2021 10:02
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During construction i would think it would add stability until all the floor joist get secured to the beams with brackets. Post build??....maybe just piece of mind

Brettny
Member
# Posted: 28 Jan 2021 12:05
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How tall of 6x6 are we talking here?

Aklogcabin
Member
# Posted: 28 Jan 2021 12:27
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Hello Willie, I believe you're on the right track with pads. RickNorth gave some good advice on controlling frost heaving. Hydrologic jacking acours around posts differently than pads.
I use traction sand or D-1 under the pad for drainage but it really helps in leveling after duff is removed. Use a 24" level both ways to level out. Then tamp. Use a bit of water on gravel and it may harden up a bit more. Folks in semi permafrost areas use this method.
Could you drill holes into the pads to accept a rod that you could place your post on. Maybe 1/2"galvanized rod. I would probably use rebar painted with rustolium paint. Either way paint them. Drill holes in bottom of posts. You could set your pads and then mark out foundation, easier to square up. Place a shingle on the block, then posts cut a bit long.
That way you can cut them to level after all are done.
Good luck. Time to start building those dreams man !

WILL1E
Member
# Posted: 28 Jan 2021 14:42
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Quoting: Brettny
How tall of 6x6 are we talking here?
Prolly 12" min so i don't have to use PT lumber on the beams and joist. Anything greater than that would be determined based on the slopes of the land.

Thanks for the suggestions Aklogcabin!

Brettny
Member
# Posted: 28 Jan 2021 15:39
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Just get taller concrete pads/blocks then. You wont have to buy an expensive post base and dont have to worry about lateral support. Level the pads with gravel. Separation between concrete and non PT lumber could be a piece of trex. Ant block should be well under the drip line anyway.

I have drilled 1/2in hole in concrete and you get quite a bit of blow out on the back side. It's not like wood.

gcrank1
Member
# Posted: 28 Jan 2021 16:20
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That just makes too much good sense.....

WILL1E
Member
# Posted: 29 Jan 2021 08:55
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I have been seeing more and more concepts where a person has a large pad on the base, typically looks like those big ones you would put below a A/C unit outside. Then they stack cinderblocks on top of that and a shingle or piece of PT board.

Not sure if they rebar and concrete the inside of those cinder blocks or not.
Beamfooting1024x76.jpg
Beamfooting1024x76.jpg


Brettny
Member
# Posted: 29 Jan 2021 10:02
Reply 


That looks good for a block foundation. By the looks of that PT it's not actualy PT it looks like normal wood coated in the stuff rustoleum sells called copper coat. The ends of the wood are very porous and will soak up any water or protector really well. This is why I suggest trex or any composite material.

https://www.amazon.com/Rust-Oleum-1904A-Woodlife-CopperCoat-Preservative-Below/dp/B00 3KR23PU/ref=asc_df_B003KR23PU/?tag=smacab-20&linkCode=df0&hvadid=193168541182&hvpos=& hvnetw=g&hvrand=5258121093272041536&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint =&hvlocphy=1023191&hvtargid=pla-309352414987&psc=1

gcrank1
Member
# Posted: 29 Jan 2021 10:45
Reply 


That pic is a lot like what mine was , only neater, on my old 'hill cabin'. I used no mortar or rods.

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