Even Poured Wall Height to T.O Ftg?

[JR55]

I recently had someone bring up that they typically detail continuous poured walls with an even dimension (whole feet) from top of wall to top of footing. I've always detailed using a 12" thick footing for small structures and used the wall height below grade to achieve frost depth (for example, 6' above grade, 2'-4" below grade then the footing). This results in a 'total' poured wall height with dimensions like 8'-4" or 6'-6".

From a constructability standpoint, should this be designed as a 8' wall with a thicker footing, simply to achieve an even dimension on the wall? Or even a 9' wall with a 12" footing and push the bottom of footing below frost depth? I've never had a contractor push back on the way I've done it up until now, so I'm wondering what standard practice is. I don't want to waste concrete, but don't know if that makes construction difficult.

 

[JStructsteel]

I detail the height they need to be. With all the genius contractors, I assume they can read more than feet.

Below grade, its down to the frost depth, bottom of footing. Wall height is less the footing thickness.

Design as required with the footing. A 6' wall with a 4' footing is a 10' structure. The soil pressure does not ignore the 4' footing height. I think thats what you are asking. Obviously the wall design is only 6'

 

[MotorCity]

Same as JStructsteel.....design it as you need it.
The client should not be financially penalized to pay for more concrete because the contractor can't read a tape measure.

 

[XR250]

I imagine they do this because the formwork comes in 12" increments and they like to screed to the top of the formwork.
Honestly, this has never come up in any job I have done to my knowledge. I think they just fudge the ceiling height to the next higher foot.

 

[dauwerda]

Having formed and poured plenty of walls, it doesn't matter. While some contractors may prefer to screed to the top of the formwork, it is just as easy to screed below the top. Whether it be screeding to a chalk line at the correct elevation (we used to use Symons forms with a wood face, so would drive finish nails every foot or so on the line to have something easy to float too without needing to see a line), or simply make a screed that looks like a cruciform, where the vertical portion is slightly less than the width of the wall, and the horizontal portion is attached such that it can run across the top of the forms while maintaining the bottom of the screed at the correct height.

 

[jhnblgr]

Concrete forms typically are 4’, 8’ and maybe 10’ tall. Also trying to float past 12” into forms in difficult to do and to see. But also adding stacker forms takes more time so more concrete is cheaper than labor. Get field experience to better understand how things work and where the cost actually exists.

 

[dauwerda]

My experience has mainly been with Symons Steel-Ply Forms, I know for a fact all of their form sets come in 1ft increments, starting at 3ft tall and going to 10ft tall.
The same is true for Western Aluminum Forms, except they start at 1ft tall.

https://www.daytonsuperior.com/docs...res/steel-ply-brochure.pdf?sfvrsn=7ae9dd60_19

https://www.westernforms.com/_files/ugd/bca8bc_e2fa011fb092433eb1bd79798657b500.pdf