20' X 24' Pole barn on 25% slope - best method?

[Egon]

Forget any of my suggestions. I did not read the original post properly!!

 

[Rustyiron]

Going to do this one time so the $$$ are not really an issue.

It's a good suggestion, had thought of this but I wasn't sure about the post construction on top of a standard foundation with footers. I had read somewhere about "wet anchors" for posts to be placed in the concrete slab, but you'd have know with total certainty where you wanted them.

You may be surprised what you're Amish crew can do (scope of job).
If they don't do the footers/poured wall portion, they can supply your concrete guy with the "Perma column" base's. They offer like you said, a wet dip that is put in the concrete just after the top of the forms are struck to elevation. They also have a drill and bolt bracket that can be done anytime after although I'd wait 14 days to let the concrete cure some.
This concrete option would also open you to conventional framing (16" or 24" o/c) and that's the best way to go if you plan on insulation and interior finishing.
The exterior finishes can be the same as a "pole barn" and you'd have the same cost advantage there. It's been my experience that the whole pole barn "thing" is a relatively inexpensive shelter for agricultural needs. The pole barn savings are in;
There's no foundation (huge)

Very little lumber (and labor) per sq/ft.

The fast and inexpensive. exterior.

If you have any thoughts of tricking this out, (with the concrete foundation) price out conventional framing and work those numbers. I learned this on one of my own buildings that had post on 8' centers, ended up framing inside 16" o/c for the insulation and wall finishes.
If you have a foundation for other reasons, (your aesthetics) that interior wall that is built to simply something to attach a good r19 insulation and drywall, it may as well hold up the building.
Too long, sorry but I hope it makes sense.

 

[DwayneB2021]

Forget any of my suggestions. I did not read the original post properly!!

No worries Egon. Good to hear any and all ideas.

 

[DwayneB2021]

Appreciate s219 taking the time to post those photos and all of these suggestions it gives me a lot to think about. Unfortunately my site is steep with a 25% grade. Attached is a photo I took with some dimensions.

Tomorrow will talk to a couple of other contractors about this - one is a concrete guy that wanted to do a "monolithic slab" which as I remember, was where walls and slab were poured at the same time. I'm sure that won't be cheap and is likely overkill but would like to get the cost of that too.

 

[DwayneB2021]

You may be surprised what you're Amish crew can do (scope of job).
If they don't do the footers/poured wall portion, they can supply your concrete guy with the "Perma column" base's. They offer like you said, a wet dip that is put in the concrete just after the top of the forms are struck to elevation. They also have a drill and bolt bracket that can be done anytime after although I'd wait 14 days to let the concrete cure some.
This concrete option would also open you to conventional framing (16" or 24" o/c) and that's the best way to go if you plan on insulation and interior finishing.
The exterior finishes can be the same as a "pole barn" and you'd have the same cost advantage there. It's been my experience that the whole pole barn "thing" is a relatively inexpensive shelter for agricultural needs. The pole barn savings are in;
There's no foundation (huge)

Very little lumber (and labor) per sq/ft.

The fast and inexpensive. exterior.

If you have any thoughts of tricking this out, (with the concrete foundation) price out conventional framing and work those numbers. I learned this on one of my own buildings that had post on 8' centers, ended up framing inside 16" o/c for the insulation and wall finishes.
If you have a foundation for other reasons, (your aesthetics) that interior wall that is built to simply something to attach a good r19 insulation and drywall, it may as well hold up the building.
Too long, sorry but I hope it makes sense.

No that makes perfect sense. I guess what you are saying is that once you have built a costly foundation there is no particular magic in a pole barn structure, might just as well be a stick built garage. Since this building is somewhat visible and near the house (its not out in the back 40) a stick built might have more options for appearance. Not sure at this point if I'd trick this out on the interior, but at least we'd have that option with the stick built. Another approach to think about.

 

[3Ts]

Your situation is ideal for a monolithic slab. I have one that was poured at the end of my barn where one corner is 6' above finished grade. The slab portion is 15' wide and 75' long. One end is 3' above grade, the other 6' above grade. The way it was formed is that the exterior form work was put up and filled and compacted on the inside. Then the walls were dug out along the form boards. Rebar put in and then concrete poured so there are no joints and since I'd planned a steel roof, weld plates were embedded in the concrete before it set up.

The far corner is 6' above grade.

 

[ultrarunner]

Must be great to off load the pickup having your own private loading dock...

 

[DwayneB2021]

Your situation is ideal for a monolithic slab. I have one that was poured at the end of my barn where one corner is 6' above finished grade. The slab portion is 15' wide and 75' long. One end is 3' above grade, the other 6' above grade. The way it was formed is that the exterior form work was put up and filled and compacted on the inside. Then the walls were dug out along the form boards. Rebar put in and then concrete poured so there are no joints and since I'd planned a steel roof, weld plates were embedded in the concrete before it set up.

The far corner is 6' above grade.
View attachment 717417

That is a heavy duty barn! Thanks for the photo, yes that's exactly what the contractor was proposing a couple of years ago when I had some other slabs poured. Should have had it done back then I am certain the cost will be up 50% today. Your lot is less steep (mine goes from 0' to 6' over 24') but seems like the principal would be the same.

 

[Egon]

No worries Egon. Good to hear any and all ideas.

With the reread I’d suggest poured concrete walls filled with dirt and a concrete slab on top of that. The walls should have a few support abutments at 90 degrees to prevent bowing out of walls where they have the deepest fill. This should give a solid base that can be built on with no rot or support problems.

Excavating a little at the front may save a bit on concrete costs but is location dependant.

 

[DwayneB2021]

With the reread I’d suggest poured concrete walls filled with dirt and a concrete slab on top of that. The walls should have a few support abutments at 90 degrees to prevent bowing out of walls where they have the deepest fill. This should give a solid base that can be built on with no rot or support problems.

Excavating a little at the front may save a bit on concrete costs but is location dependant.

Yes I went out to the site again this morning and that's my conclusion too. So now it's off to get some quotes on the monolithic slab like "3ts" showed in his photo. Hopefully I can find someone to do this whole project, concrete + barn/garage construction.

 

[EddieWalker]

If money wasn't an option, then the suggestions of a solid foundation would be the best choice. If it was me, I would listen to the Amish and build a deck from wood and put the barn on top of the deck. It would be very easy to build it strong enough to park a vehicle in there. That's actually very simple, but it does have to be done right. Not like most people build decks next to their houses, it will require proper sized beams and joists. There are span tables online to figure this out, but if you are unsure, an engineer could work this out for you in about an hour.

 

[Iowachild]

Side hill?

Dig into the side hill wider and deeper than than the pole barn. Dig & fill method. Get a nice gentle back slope to the excavation. If suitable use the excavated material to pad out in front of the excavation. Finally make a drainage ditch around the side and back of the excavation. Then use ordinary building procedures With cement floor.

Six foot depth may/will end up as less using cut & fill method.

This is what I did for my 24' x 40' building. That back bank is 7 foot high.

 

[DwayneB2021]

If money wasn't an option, then the suggestions of a solid foundation would be the best choice. If it was me, I would listen to the Amish and build a deck from wood and put the barn on top of the deck. It would be very easy to build it strong enough to park a vehicle in there. That's actually very simple, but it does have to be done right. Not like most people build decks next to their houses, it will require proper sized beams and joists. There are span tables online to figure this out, but if you are unsure, an engineer could work this out for you in about an hour.

Yeah the Amish barn builder gave me a tour of a huge pole building they erected near me, no doubt their work is exceptional. But they aren't cheap, about the same as the concrete slab approach.

 

[Bentrim]

Have you considered precast concrete walls? or possibly poured concrete walls and the backfilled with stone for a solid floor?

 

[DwayneB2021]

Have you considered precast concrete walls? or possibly poured concrete walls and the backfilled with stone for a solid floor?

Yes that's probably the leading candidate at this point. Finding a good contractor who will handle both concrete and the construction isn't easy though.

 

[jthibodeau89]

When i had the pad built up for my 36x66 shop we had the entry area at mid slope. Material was moved from up slope side (5') to downslope (6+'). The fill is compacted clay chirt. When i noted that the slope on one corner went too close to a boundary fence, the contractor pulled the slope back to original grade for the 10' clearance to the fence and brought in 17ea 2'×2'×6' blocks (3500lb ea) to make a retaining wall 5' off of the slab edges at the offending corner. The blocks are keyed and produced from excess concrete material. The exterior face of the blocks has a round river stone appearance. My wall was 3' high (2 courses). These blocks stack vertically. I should note that we are in TN, and our frost line is 6".

 

[ning]

What's the minimum setback per local code? 8' is legal, or are you just going for it? (Here we're at 30' minimum! )

 

[JWR]

It really depends on what you want to spend. If it is a forever building, doing it once and have the money then do it with poured concrete walls and foundation. Install some posts in the middle for load bearing and go up from there with whatever structure you choose. I see no need to fill the foundation with stone or soil or anything else. Make sure it is drained well around the perimeter. If surroundings allow/fit/you like I would still put in an access door of some sort on the high back side for storage.
If money matters, simply use the Amish and let them do the entire job. Do they have excavation equipment or access to it? So far as wood is concerned do not be that worried. You can by "ground contact certified" wood that is WAY better than typical so-called treated lumber these days. The Amish know this. Insist that it be used. If you are concerned at all with rot, find somebody with a stash of creosote and add creosote to treat the 6x6 or whatever sized vertical wood. I think they should be set in fairly thick concrete bases.
I built a garage for my tractor and tools and lumber for projects, etc. about 40 years ago. I used ground contact treated wood for the vertical posts including several "in the middle." Poured cement around each post. Framed around the posts with 2x10 lumber and then built the floor over that base. My floor was 3/4" treated plywood over structural joists, etc. That part should be done depending on what loading you want to allow. I had a removable section of floor such that I could stoop underneath and go up under cars without using a lift for oil changes, etc. Above ground was ordinary frame construction with vinyl siding and custom ports in the left and right eaves to allow insertion of long length lumber for storage on inside shelves built under the steep hip roof rafters. I did the entire job myself. Cheap and permanent.

My lot was about what you say -- 25% slope. Within maybe 4 feet of a fence on one side and 12ft in the rear but woods outside of that.

Post mortem: A huge poplar tree some 70 feet tall and 2 to 3 ft diameter came crashing down on my building (during aftermath of a hurricane.) I had sold the property around 10 years before that happened. My "Spare Garage" was demolished except that my floor supported the trunk of that tree. The newer owners rebuilt the building using my same floor and post foundation which was still in tact and sound.

 

[BoylermanCT]

My pole barn had a 4' slope from front to back. We brought in truckload after truckload of fill to bring the site level. We compacted it every 4" as we went. We had the fill extend 6' past the back wall of the barn so I could mow behind it to keep it maintained. Then it slopes down at a 45 degree angle 4' to ground level. A 16 yard load of fill is $250 here in CT. We brought in somewhere around 10-12 truck loads so it added up, but was the best solution for my site.

I do like the giant block retaining walls referenced earlier. That would have been my second choice if fill did not solve the problem.

 

[civilian]

Any way to move the building forward? Towards the garage door side? Gives the potential to have more slope to the road behind. Also your picture with the markers and sizes, seem lke the road is hidden by trees/bushes? This would be a lot easier if the ground sloped up and not down from the front. Good Luck. Jon