50x75 Mueller building - Concrete advice needed

[mdeisenhauer]

Hello, new to the group here and looking to get some advice if you have it. I recently made a down payment on a 50'x75' building with 16' eaves and 24' peak. Delivery is expected +/- 3rd week of June. I went to a coworker recommended concrete and erector guy and his proposed slab was monolithic, 4" field with 12"x12" perimeter beams. To me, with the vertical size driving higher loads to the 8 beams of loading, I don't think 12"x12" beams are adequate. Through a little research of a similar sized building, I've seen 24"x24" used and think that would be adequate. For good measure, but maybe overkill, I was thinking of adding two beams across the load bearing beams in the middle as well. To note, my soil is sandy down to 7 feet.

Does anyone have a similar sized building and can share your foundation details? Or, should I get plans engineered and if so, do you have any recommendations for someone who could do it? Thanks!

 

[bb29510]

just do what the mfg says

 

[mdeisenhauer]

Problem is, mfg doesn't offer any foundation support other than calculated loads. Customer is on their own for the foundation due to liability.

 

[600SL]

I sort of have the same problem. My manufacture will sell foundation planes for $3500. Last time I built a building from them 10 years ago is was about $1000 so I bought the planes. So now I'm using those planes as a guide for my new foundation. But I think the old planes I have a really over kill with lots of rebar. Fortunately my town does not seem to be nit picky about it. Maybe because CT is almost solid rock.

I think the planes I have are overkill because they are not around to evaluate your soil so a local designer may be the best bet.

 

[cvairwerks]

If you are sandy soil, you need someone that knows how to deal with that, to design the foundation. Where one of my places is at, they build a new, 1400 sqft house and it took 20 piers almost 15 feet deep to crate a stable foundation. When they did the perk test for our new spetic system, they went down over 84 inches and had nothing but red sand in the diggings.

 

[jmountainjr]

I can't tell what part of the country you are in, but will assume to start frost protection isn't a factor. Regardless of where you are, you need well drained soil that is compactable. Typically 12" deep of gravel or stone dust. Many states have adopted International Building codes, so I would make sure of your area before committing to a plan. Both frost protection and energy conservation requirements can impact the concrete design. Generally around here once you exceed 600 sq.ft. it may be cheaper to go with perimeter wall and separate floor than floating slab on grade. Especially for a steel building. Depending on what you will do in the building, a 4" thick floor may be on the lite side. Good luck with the project.

 

[Hobby_Man22]

Is this red iron? Everywhere there is a column, there is a beam that goes across, along with a beam around the perimeter. Then you have hook style anchor bolts that go into the slab before its poured. I guess it depends on the local code. I had an engineer make a foundationn plan that appeased the local codes. My beams are 12x24. Like I said, that's just my building yours may be different. I've heard up north that the beams have to be 5 or 6ft deep to prevent frost damage

 

[Hobby_Man22]

Problem is, mfg doesn't offer any foundation support other than calculated loads. Customer is on their own for the foundation due to liability.

Due to different building codes. You need a local engineer to make a foundation plan. The building company tells you where the anchor bolts are supposed to go

 

[My Old Tools]

In some places with very stable sandy soils you can get away with a flat slab or minimal beams. In more active soils like black gumbo around Dallas, you can go to China and it will still move.

 

[chad215]

did this concrete guy use the actual reactions provided by the manufacturer or did he just basically say "this is how we do it"? These foundations should be designed for the actual loads given by the manufacturer- every building could be different.
My 40x50 in Texas was 5" nominal with 18x18 perimeter and cross beams.

 

[rancherbill]

Problem is, mfg doesn't offer any foundation support other than calculated loads. Customer is on their own for the foundation due to liability.

No manufacturer will recommend a foundation because EVERY SITE in EVERY STATE in EVERY SOIL CONDITION in EVERY CLIMATE requires it to be built differently.

You have to talk to a local builder or go to your local building inspectors or state Dept. of Agriculture to see what is locally the right way to go.

 

[Hooked]

Try a local foundation engineering firm, if any are available in your area. That's what I did for our 40'x60' with 14' eaves. I think the cost was around $200.

 

[readhead]

For that size building there should be concrete tie beams between the rigid frame piers.
This is not a guessing game. You should be talking to a structural engineer about designing a foundation plan.
The reactions supplied by the building company are to be used to design the foundation.

 

[mike93lx]

Try a local foundation engineering firm, if any are available in your area. That's what I did for our 40'x60' with 14' eaves. I think the cost was around $200.

How long ago was that? $200 feels like the cost of taking the phone call

 

[strutaeng]

The few foundations that I've designed for pre-engineered metal buildings (PEMB) have a "tie beam" at the structural bend or frames.

The PEMB specs will give you the loads or reactions at the base of the bends. There are horizontal forces at the bottom of the bends towards the outside of the building face, in addition to the gravity reactions. The tie beams resist this outter thrust forces. I would recommend you get your foundation engineered.

As mentioned, the PEMB don't do foundation design, so you have to hire an engineer for the foundation. Pretty standard procedure around here.

 

[Moss]

When I was planning the foundation for my red iron shop I had a few concrete guys come out to quote and they didn't even look at the plans. Even after I had an engineered slab design done (24" thick edge FYI) they still just talked about there normal foundation plans they did on stick built and quoted that. I ended up with a great concrete guy and we got new plans and built it on a wall built up a foot above grade with larger footings at post locations. I am very happy with that decision. Shop is high and dry.

 

[dcg9381]

Hello, new to the group here and looking to get some advice if you have it. I recently made a down payment on a 50'x75' building with 16' eaves and 24' peak. Delivery is expected +/- 3rd week of June. I went to a coworker recommended concrete and erector guy and his proposed slab was monolithic, 4" field with 12"x12" perimeter beams. To me, with the vertical size driving higher loads to the 8 beams of loading, I don't think 12"x12" beams are adequate. Through a little research of a similar sized building, I've seen 24"x24" used and think that would be adequate. For good measure, but maybe overkill, I was thinking of adding two beams across the load bearing beams in the middle as well. To note, my soil is sandy down to 7 feet.

I have a Mueller 40x60x16. Mueller isn't going to give concrete advice. That's normal. Want a real answer, this is an "engineered concrete foundation" question that you can have answered for a few dollars ($1-2k?) after you do a soil samples test.

The steel building concrete guys do this so often they just throw it down. That always makes me nervous. You're gambling because they're not going to come back and fix it.

I took a risk on it too. Non-engineered. But I knew I was building on a limestone shelf and I also have guy who has probably done 30-50 of these buildings over the last 5 years and he knows what works in the area.

This is the foundation that I designed and how we did it:




I'd recommend adding these details on these buildings also:

• Rat lip around the perimeter
• Drop the concrete where the garage doors. Slope or step down.

 

[dcg9381]

I sort of have the same problem. My manufacture will sell foundation planes for $3500. Last time I built a building from them 10 years ago is was about $1000 so I bought the planes. So now I'm using those planes as a guide for my new foundation. But I think the old planes I have a really over kill with lots of rebar. Fortunately my town does not seem to be nit picky about it. Maybe because CT is almost solid rock.
I think the planes I have are overkill because they are not around to evaluate your soil so a local designer may be the best bet.

I don't see how these are worth a dime other than checking the box of some local jurisdictions. I did my own (see above). If you need an engineered foundation, you need to know what's under it.

 

[mdeisenhauer]

I have a Mueller 40x60x16. Mueller isn't going to give concrete advice. That's normal. Want a real answer, this is an "engineered concrete foundation" question that you can have answered for a few dollars ($1-2k?) after you do a soil samples test.

The steel building concrete guys do this so often they just throw it down. That always makes me nervous. You're gambling because they're not going to come back and fix it.

I took a risk on it too. Non-engineered. But I knew I was building on a limestone shelf and I also have guy who has probably done 30-50 of these buildings over the last 5 years and he knows what works in the area.

This is the foundation that I designed and how we did it:




I'd recommend adding these details on these buildings also:

• Rat lip around the perimeter
• Drop the concrete where the garage doors. Slope or step down.

Thanks for the info, that's basically what I have worked up so far, but I'm old enough to have mine drawn on engineering paper and not CAD. I actually know more than I let on to, I took Reinforced Concrete as an elective way back in my college days. I shouldn't have sold the book back for beer money though. Since I'm new to the group, I was just feeling things out with my question. I'll run some calculations and just error conservative. Now the real hard part, to find a decent contractor!

 

[dcg9381]

Thanks for the info, that's basically what I have worked up so far, but I'm old enough to have mine drawn on engineering paper and not CAD. I actually know more than I let on to, I took Reinforced Concrete as an elective way back in my college days. I shouldn't have sold the book back for beer money though. Since I'm new to the group, I was just feeling things out with my question. I'll run some calculations and just error conservative. Now the real hard part, to find a decent contractor!

I make ZERO claims to any special concrete knowledge. And certainly hand drafting is just as good as CAD (I learned both, but I'm much faster with 2D CAD). This foundation is my design, based on some consultation with several GCs, looking at several buildings, and knowing what is under the pad.

I did "engineer" a house foundation and we ended up having to put in 12 10' piers... We build a garage on "unknown spoils" that were not native soil.

Again, a lot of this depends on what is under that shop. We had a foundation done in Michigan - totally different...

Where I do know something is that the "rat lip" and dropping the concrete for the doors are nice features to have.

 

[Hobby_Man22]

I'm sure they have some kind of software that allows them to design something like this in 15-20 minutes

 

[Hooked]

How long ago was that? $200 feels like the cost of taking the phone call

LOL.....about 15 years ago

 

[mike93lx]

LOL.....about 15 years ago

Ok, so 2500 in today's dollars

 

[dcg9381]

I'm sure they have some kind of software that allows them to design something like this in 15-20 minutes

And an education that requires 4-6 years to graduate, assuming you can pass the PITA PE test... Then you can use that software and add your own stamp.

You can't design jack squat until you know what the soil conditions are.

 

[mdeisenhauer]

Ended up pouring earlier this week. I went a little overkill due to getting such a sweet deal on make up and finishing (guys did the make up and finishing for $2.65 sqft). They furnished the forms and I bought the steal/poly/chairs/stirrups/etc. 12"x24" beams for the building, 12"x12" for the porch and one additional 12"x12" interior beam for a planned load bearing wall. Used 4,000psi concrete and the field is 5 1/2" thick. 105.5 yards total