I don't know anything about concrete, but have a project coming up soon. Is the below specs enough for a 30x50 steel building? Am i getting ripped off at $7 a square foot that I was quoted?

4" Slab
8" beam around the outside edge + one down the center
#3 rebar 16" on center
3500psi concrete
moisture barrier

10,500

 

How many quotes did you get ?
Should get at least three and that would give you an idea as to what pricing is in your area.

 

I am not, but been watching alot of Victory's videos. He is a concrete guy out of Wisconsin.
Helps if you can see some of the similar jobs they have done as well in progress.

Also agreed, I would get a few Quotes.

 

the best quote that I received before this one was 13,500. The company that I bought the steel building from recommended him for the concrete work. it was all a very spur of the moment purchase. I stopped by a metal structure place on the side of the highway to look at a carport and they were wrapping up a memorial day sale that expired yesterday. I spent a lot of money not expecting to spend.

30x50 with 14' walls and a 3/12 pitched roof. I upgraded the frame from 14 to 12 gauge, and the walls from 29 to 26 Gauge. 2 12x12 electric roll up doors and a few other little details. I'm hoping closed cell foam is in the budget along with A/C and lifts.

 

@strutaeng

 

Not a concrete expert but looking forward to seeing your build

 

@TXsilverado You are in the Austin area, right?

I've got compadres that do have concrete contracting business and I can for rough prices. That unit rate seems about right for DFW area though.

I'm a structural engineer, so maybe I can offer guidance on the design:
1. Do you have an idea on the metal building manufacturer? Will it have perimeter load-bearing walls? Or frames? Load distribution matters somewhat.
2. How deep is the perimeter grade beam? I would recommend at least an 18" deep x 12" wide beam. Reinforcement can be (2) #8 top and bottom bars with stirrups at 18" on center. Use #3 dowels between the slab and the grade beams. This is kind of overkill and will drive the cost up, but see why below.
3. I'm sure you know this but most of our Texas soils along the I35 corridor, and east suck because they move a lot with moisture variations throughout the year. The deeper grade beam and reinforcement is more to resist (but not eliminate) that movement.
4. Adding things like brick veneer and Sheetrock on walls will make things more challenging if you like in an area with expansive soils. That's really a site-driven issue and requires a geotechnical engineering soils boring/report. In few areas, limestone or caliche are very shallow, which is great because they don't move around like the fat clays.
5. If you have a lift planned, you can do a thickened slab in the general area of the posts. An area 4' square, 8" thick is probably good enough. Garage journal is filled with guys having issues installing a post lift and blowing through their regular thickness slab. SMH

I hope this helps.

 

Thanks. I'm in a suburb on the north east side of Houston. New Caney if you are familiar with the area. Like i said, I'm a concrete moron so a lot of what you posted above is greek to me. It gives me some terms to search up and learn the lingo though. The specs that they posted above is all i've been told.

The frame will be a 2.5" 12 ga square tube so I doubt that the walls will be load bearing. They said 8" beam. Is that the same as the parameter beam?

 

Ouch those prices hurt.

We have pretty good soil here and i built on top of a hill.

Me and father-in-law did all the dirt work and forming and footings for house and shop so only thing i sub'd out was the finishing.

Im no expert but i know if they suggested a 12x12 footing is enough then i went larger and added more rebar and wire haha.

If i recall correctly i think we only spent $22k on 150 yards of concrete, rebar, wire, moisture barrier, and finishing.
I did 6" thick 4000psi for the shop and house which the house is a red iron building i just covered all the iron.
The footings where each post landed have 36x36 footings with rebar and wire.
None of the walls are "load bearing" since they are free standing and not necessarily connected to the iron.

Thinking back now tho, those were pre covid prices so that makes a big difference



If your post/rafters are only 2.5" sq tube then i dont see you needing a whole lot of fancy footing work to support that.
Are they going to do metal weld pads in the slab to weld the post to?

 

8" perimeter grade beam? Probably. Not sure if that's the depth or the width? Both? Some very small buildings like a shed you can get away with something like that. It's basically a thickened perimeter slab edge, not a true grade beam. They problem is over the years, you will likely get some soil erosion and the underside might become exposed. On my design projects, I've normally seen 18" or 24" deep grade beams minimum on the geotechnical reports. The geotechnical engineers I've asked why, they tell me it's to help create a seal to mitigate moisture changes, which is what causes the slab to move around. Again, it's not prevent it, but to minimize it.

My recollection of north Houston back many years ago when I was surveying hurricane damage, was the soils were pretty expansive. Houston soils in general are like that, same for DFW.