Slab at top of ICF Wall

[LevisL]

I'm trying to model this ICF foundation with a slab sitting on top of it.

 

 

I've tried a couple methods, but both have their drawbacks:

1. Build foundation with the slab at the top of the stem wall (main floor slab provided by foundation).

 

The problem with this method is that the slab sits INSIDE the stem wall instead of ON TOP. It requires a bunch of CAD work to mask it and show like I want in sections. You also end up with an odd gap at the inside foam layer for some reason...

 

2. Set my main floor structure to be a concrete slab.

This method looks much closer to what I want, except the siding extends down to the bottom of the slab – I want the siding to start at the top of the slab/bottom of framing. This appears to be hard-coded in Chief. Am I missing something?

 

Any other suggestions?

 

Thanks in advance,

[ShaneK]

Use the slab or poly solid tool and do what you want. 2 minutes and 47 seconds.

ICF on top.plan

[AvoyeDesign]

Pick the one that gets you the closest to what you want and use cad overlays to get the sections right.

[LevisL]

Thanks guys. Appreciate your feedback.

 

Rod, that's pretty much what I ended up doing. I also added a couple material regions on the exterior to mask where the siding extended lower than I wanted it for my exterior elevations and renders.

 

ShaneK – your solution achieved the same result as setting the main floor structure as a slab... the siding still extends too low! 

 

I was hoping I was just missing something, but I guess not! It would be nice if we could control if we want the siding to cover the edge of the slab or not when we set the main floor as a concrete slab.

[ShaneK]

You can control siding height with pony wall or wall material region or polysolid or,,,,,,,,,,, nothing is a one click and that's the trick!!! lol

[rlackore]

15 hours ago, ShaneK said:

You can control siding height with pony wall

 

Yes, Method 2 with the upper floor using a pony wall with height above floor set to 0":

[LevisL]

1 hour ago, rlackore said:

 

Yes, Method 2 with the upper floor using a pony wall with height above floor set to 0":

 

I thought of doing that, had the grading been flat around the house. Since the grading slopes down and I needed to add wall material regions for my parging anyway, I just made those material regions a bit taller to cover the edge of the slab. It was a bit of a pain to get the corners to look nice since the material regions don't wrap around (I ended up using small slabs on the corners), but it worked.

[Kbird1]

9 minutes ago, LevisL said:

 

I thought of doing that, had the grading been flat around the house. Since the grading slopes down and I needed to add wall material regions for my parging anyway, I just made those material regions a bit taller to cover the edge of the slab. It was a bit of a pain to get the corners to look nice since the material regions don't wrap around (I ended up using small slabs on the corners), but it worked.

 

I use Method 2 as well  ( Method 1 would only happen if Hang Floor inside Walls was checked I believe? ) but I use a Pony Wall with the ICF already Parged so it does that all Auto, the height of the pony wall controls the height of the parging.

 

Building the Foundation at 4" Slab, Auto detailing, then Setting the Floor to the thickness of the Siding Hang down ( 1-1 1/2" typ) , and hitting Auto Detail again , gives you multiple CAD Boxes to play with and sending them to Front or Back Drawing Group, makes it all look good in section and seems to work Ok.

Replacing the ICF AutoDetail Insul. Fill will let you cover the PonyWall line BTW.

 

Have to ask......Is the Siding really only brought to the bottom of the Framing ...just seems like a bad idea to me re water penetration.....

 

 

[LevisL]

9 minutes ago, Kbird1 said:

 

I use Method 2 as well  ( Method 1 would only happen if Hang Floor inside Walls was checked I believe? ) but I use a Pony Wall with the ICF already Parged so it does that all Auto, the height of the pony wall controls the height of the parging.

 

No, I did not have 'hang floor inside walls' checked. That's just how slab at top of stem wall seems to work.

 

I also use the pony wall method for my parging when the grade is flat, but it doesn't work well for sloped sites (in this case 2.5 ft drop from front to back)... at least for how I like to show my exterior elevations! I only want the parging to show above the terrain, so I use material regions, like this:

 

And I'm not overly concerned about water penetration by having the siding stop at the top of the slab, as long as they properly flash and caulk that joint (which I've detailed). It's only for part of the building anyway, as the siding actually steps down lower where the footing steps lower. Plus, the siding for this project is wood 2x6 log siding, so I'd rather keep it up higher above grade so it doesn't sit in wet snow too much in the spring!

[Kbird1]

7 minutes ago, LevisL said:

That's just how slab at top of stem wall seems to work.

 

 Ahhhh that's the difference , I don't use that Checkbox ever since I want the Slab on Top of the Foundation Wall not level with it ( which is what I thought you wanted too? ) that's why I though you must have checked the Hang Floor inside Foundation Wall Box as I had forgotten about this Checkbox too

[LevisL]

5 minutes ago, Kbird1 said:

 

 Ahhhh that's the difference , I don't use that Checkbox ever since I want the Slab on Top of the Foundation Wall not level with it ( which is what I thought you wanted too? ) that's why I though you must have checked the Hang Floor inside Foundation Wall Box as I had forgotten about this Checkbox too

 

Yeah, I don't do this type of foundation too often, so I wasn't sure the best way to go about it. I remembered seeing 'slab at top of stem wall' as an option when building the foundation, so I figured I'd try it. In my mind 'at top' meant 'on top', but I see now that I was wrong! Oh well... method 2 with pony walls if I ever have to do another foundation like this again!

[Kbird1]

1 hour ago, LevisL said:

 

Yeah, I don't do this type of foundation too often, so I wasn't sure the best way to go about it. I remembered seeing 'slab at top of stem wall' as an option when building the foundation, so I figured I'd try it. In my mind 'at top' meant 'on top', but I see now that I was wrong! Oh well... method 2 with pony walls if I ever have to do another foundation like this again!

 

Well, you and I wouldn't be the only ones confused by some of the wording in Chief's DBX's I am sure

 

M.