Concrete slab question.

[JTCowpoke]

I bought my building from Metal Mart and they provided the concrete plan.

[Ironman]

Is that ledge 2 inches both ways, in and down? That would mean, ideally, that the slab dimensions should be 30' 4" x 40' 4", correct? Considering that the building is a true 30x40. I don't know if market standard building dimensions would be slightly smaller to fit on a market standard "notched" slab. Just curious. You know, kinda like a 2x4 board is not actually 2x4. Lol. Thanks.

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Sheet ledge is 1 1/2" x 1 1/2". Slab will be 30'3"x40'3". Been doing these things for over 40 years.

[BowPro73]

Who are you purchasing building from? I'm looking at one of these for a commercial processing place. I would think these are durable and way cheaper than finding a contractor to do a build out.

I don't have one yet. About to start looking here in the future. I've heard that there are good building kits out there that are cheaper than Mueller. Haven't researched any yet though.

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[miket]

Sheet ledge is 1 1/2" x 1 1/2". Slab will be 30'3"x40'3". Been doing these things for over 40 years.

The 2x4 on top is a good idea. Been using 2x2 furring strips for mine here at the house. 2x4 on top never occured to me Have the forms sitting right now waiting on a truck.....hopefully they will fit me in sometime this week.

[sendit]

Most contactors are going to use a 2x2 for the drip ledge for the R panel so add 3" to the total width and length you desire.

30'x40' building is going to have a slab that is actually 30'3"x 40'3"

X2 just in case the OP didn't read this

[Ironman]

The 2x4 on top is a good idea. Been using 2x2 furring strips for mine here at the house. 2x4 on top never occured to me Have the forms sitting right now waiting on a truck.....hopefully they will fit me in sometime this week.

Yes. Much better and faster than 2x2. Stiffens your form board so not as many kickers needed as well. Can re-use your 2x4. Just remember to set your form board 1 1/2" low, as the 2x4 on top will bring finished floor up to correct height.

[BowPro73]

The 2x4 on top is a good idea. Been using 2x2 furring strips for mine here at the house. 2x4 on top never occured to me Have the forms sitting right now waiting on a truck.....hopefully they will fit me in sometime this week.

Cool. I wasn't sure if all metal buildings were a true 30x40 measurement as advertised..... like the good ole' industry standard 2x4 board not being a true 2x4. Thanks

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[Ironman]

Cool. I wasn't sure if all metal buildings were a true 30x40 measurement as advertised..... like the good ole' industry standard 2x4 board not being a true 2x4. Thanks

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Yes. Out/out of the STRUCTURE is 30x40. Out/out of wall sheets will be 30'3"x40'3".

[Texastaxi]

The slab will be 3" bigger than you nominal building size, both directions. This was mentioned earlier. The 1 1/2" on each edge is for the sheet ledge, also mentioned above.

You will get a concrete PLAN with your building order, IF you use a reputable manufacturer. This PLAN is overall sizes, with door inlets, and anchor bolt locations.

The PLAN will not include DETAILS. Details are thickness of the slab, locations/dimensions of beams, and size and placement of rebar. You will need a geotech report and a structural engineer to get that part right (unless you just go crazy overkill on all of it). The slab is the worst place to try to cut corners. If it cracks or sinks, you'll spend a lot of money to get it back.

[dhall]

Make it 3" bigger each way

[dhall]

Any good concrete guy should know

[jrfan]

Just had my 40’x 40’ installed. Rafter-p construction built it and the slab was 40’3”x 40’3”
They used a 2x2 nailed around the top of the Form for the drip edge. It turned out great.

[Take Dead Aim]

The slab will be 3" bigger than you nominal building size, both directions. This was mentioned earlier. The 1 1/2" on each edge is for the sheet ledge, also mentioned above.

You will get a concrete PLAN with your building order, IF you use a reputable manufacturer. This PLAN is overall sizes, with door inlets, and anchor bolt locations.

The PLAN will not include DETAILS. Details are thickness of the slab, locations/dimensions of beams, and size and placement of rebar. You will need a geotech report and a structural engineer to get that part right (unless you just go crazy overkill on all of it). The slab is the worst place to try to cut corners. If it cracks or sinks, you'll spend a lot of money to get it back.

Nailed it. People skip the Geotechnical and engineering and take low price on concrete all the time. I see what people say they paid or were quoted and I'm dumbfounded. I pour concrete for a living and can't do it for cost of what some on here pay. I always wonder how long the slab will last at $4 to $5 a sqft?

[manwitaplan]

Nailed it. People skip the Geotechnical and engineering and take low price on concrete all the time. I see what people say they paid or were quoted and I'm dumbfounded. I pour concrete for a living and can't do it for cost of what some on here pay. I always wonder how long the slab will last at $4 to $5 a sqft?

Same boat as you. I pour concrete for a living and get called all the time by friends for help and they give me their guys price and no way I can do it for that. But we do it right every time.


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[Texastaxi]

Nailed it. People skip the Geotechnical and engineering and take low price on concrete all the time. I see what people say they paid or were quoted and I'm dumbfounded. I pour concrete for a living and can't do it for cost of what some on here pay. I always wonder how long the slab will last at $4 to $5 a sqft?

I DID pour my 40x80 for about $4.55 a square foot.

BUT, I work for an engineering firm, so I had a PE (that's a good friend) run the calcs to give me bar size, bar spacing, beam size and beam placement. I did the detail drawings and gave them to my contractor. He added a few things that he likes to add, like a 3'x3' chunk, where the beams intersected under the columns. He got it all dug out, then it rained. So my beam got re-dug, a little bit bigger. I bought all the rebar and hauled it to the site. I paid the concrete company direct, as well as the pump truck. Basically I eliminated the markup on the materials. The contractor was actually OK with it because he's a mom-n-pop shop and he didn't have to front any cash.

I know this won't work for everyone, but that's how I did it.