Frost wall/Pony wall Rear Walk-Out

[Munshaw]

Hi there,

First time poster, long time lurker. Have been slowly learning the program, and designing my house (Chief X5) for construction (maybe 2 years out still...) on a rear-sloping lot. Building a 2000 ish sq. ft home with 8" icf basement walls, rear walkout, with a 4' frost wall below basement slab. I was able to figure out how to step the footings properly through other threads on this site, but one step seems to be eluding me. The rear wall will be ICF frost wall below, and conventionally framed above grade. I will likely carry the ICF around the rear 90 corners for strength, but that is not (yet) reflected in the plan.

Anyway, my question is as follows: My understanding is that one way (the best way?) of constructing a frost wall below, with conventional framed wall above is to use a pony wall. However, my footing seems to want to stick to the bottom of the framed wall, rather than stay put below the frost wall when I do this. I've seem pictures of other plans who seem to have success getting the footing to stay put, but I keep getting this weird footing arrangement.

Is there a better way to do this? Or a way that will "trick" Chief to keeping the footing where it is?

Basement is 8'8" interior height, with 4' frost wall below grade, to allow for full courses of ICF forms (nudura, 18" high). Is there a problem with my pony wall settings? I'm setting the "height off floor" for 0", which gives me automatically "elevation of lower wall top" of -117 1/8" ???? Something doesn't seem right there, but I can't figure out what... Doing the inverse (elevation of lower wall top) results in ICF all the way up, with the footing at basement slab level (incorrect).

Please help! I have lots of time to figure this out, but this one has me stumped...

Thanks guys, this has been a real learning curve, but this forum has helped out immensely. Some very talented folks on here!



*note- door is just a place holder to determine grade from the exterior.

[Curtis Johnson]

Can you save your plan, close the plan, zip/compress it and then post it hear. Hard to decipher your predicament without being able to analyze what you have.

[Munshaw]

As requested!

[Munshaw]

Please excuse the rest of the design above the basement. I know I'm ahead of myself in several areas, and there are several structural problems. I did a layout up and dressed it up a bit to get approval from my better half of the concept, and am now working my way up resolving structural issues as I go. Any opinions on floor plan considerations are also appreciated! Finishing/ coverings are just concept placeholders for now. The roof took me forever to figure out, and the gable end walls are giving me some grief as well. I am pleased with the overall roof line however! Very different from what I typically see in my part of the country.

Edit: I was actually hoping you'd chime in here Curtis, I used several of your threads/posts as references to get me to where I am.

[David J. Potter]

Take a look at some of these help database articles I found using the search term "stepped foundation", one or more of them will address your concerns:

http://www.chiefarchitect.com/search...put=xml_no_dtd

DJP

[Curtis Johnson]

Munshaw:

You needed to set the pony wall at the proper elevation (basement slab). Also, X5 ICF main layer needs to be changed to outer foam or you'll see a notch in the corner of the ICF walls (lower pony wall). Your gable roof just needs to have the wall in the right location (and height) ... and make sure your roof planes butt up against the outer edge of the siding on the Dutch hip gable walls. I did have a little trouble with that pony wall footing as well until I looked at it in an elevation section and then selected it and pulled the bottom edge down to match the top of the other wall footings [I had done some other things with it so I needed to pull the bottom back down anyways].



You should select your siding wall and change the default siding material to your siding (via Plan Materials) ... assuming you are staying with the Cypress material. Build your terrain and set as needed and your deck/porch stairs will have a place to go to. Not sure how you plan to support the big overhangs since you have those on a shallower pitch! Are you planning to have more porch in those areas (and posts/beams)? You should make the one wall that is to have stone a pony wall as well with stone on the bottom .... you'll need that stone "pattern" for your vector view elevations. You need the real thing (stone) for any render or ray trace views. There should be one stone material in the library you can quickly get at without having to go to any of the manufacturer libraries (Cultured stone, Eldorado stone). You'll need to pull your floors out to support those nice columns (no overhangs). Some of your roof planes aren't completely joined ... select the edge of one, then click the # 2 on your key board and then the adjoining plane and the "should" join. If your stairs is going into that room area with the railing, you should put the stairs in soon before doing too much more ... stairs always take up more room that it seems like they should ... you may have to move your walls around to make things nicely fit.

Looks like a nice project ... good luck.

[Munshaw]

I'm going to take a little while to implement some of your ideas. With two kids under three at home, my time to spend with Chief comes in fits and starts. Thanks kindly for the advice. As far as the overhangs go, that is what I referring to with my structural issues. Those need to be addressed and supported as needed. The only thing I need more clarification on is what you are referencing with changing the layers to outer foam? You suggest not using ICF wall, and sizing an outer foam wall to match the thickness of an ICF wall instead? i.e. 13.5" ?

[Curtis Johnson]

If you have the time, definitely spend it with your children. I forgot about your comment about the structural issues. Regarding the ICF and changing the main layer, your presently set up to match the main layer of your ICF with the main layer of your framed wall. This is where the problem comes in since your present ICF wall definition (Chief's OB default setting) has the inner concrete core as the main layer. In other words, you'll be matching the outside of your stick wall framing to the concrete in the ICF ... check it out ... you'll see what I mean.

I design with ICF's all the time. I built homes with them for several years before exclusively switching to design work. I never have used Chief's X5 and earlier ICF wall definition for several reasons. I just use one layer that accounts for the space of the two outer layers of foam and the inner concrete core. That way I never had to worry out those corner notches, interior wall connections, etc.

Here's an image of what happens when the ICF concrete is the main layer:



This isn't exactly the issue you have that I was talking about but it stems from the same problem of using the ICF concrete at the main layer. When you fix your ICF foundation pony wall extending below grade and see how it connects with the perpendicular stepped ICF side wall, you'll see what I am talking about when you take a render view of the corner.

[Munshaw]

Curtis, I definately see what you're saying about having the face of the foam line up with the sheeting above. It does look much better all lined up. How does this play out in actual construction however? The construction of the last house I looked at with an ICF basement and framed first story, the rim joists of the first floor came flush with the outer edge of the concrete part, and not the foam. The foam was them capped with aluminum, and flashed up the sheeted wall, over which the stone veneer was applied. I suppose it would depend on the thickness of your choice in finishes it it looked good or not...

I have no experience working with ICF other than helping a couple friends with the actual pour, and seeing the house well after the framing is done, so I am not familiar with this connection point (yet!).

I plan on using Nudura ICF forms, which offer a top-course form that "flares" the concrete outward at the top course called a "Taper Top Unit", with a diminishing outer foam panel. Seems like that might be the product I'm looking for, which would result in the Chief plan being accurate with my actual construction technique and choice of form??? Thoughts??

(Sorry, I know we are not straying from original topic. I try to glean information where I can, when I can, from people who know more than I do! )

Edit: Looking at the details for the first floor/wall connections on the Nudura installation manual available on the website, your reccomendation would result in a "correct" representation on the outside of the building. The sill plate/gasket rests entirely on the concrete, and the rim joist is actually shown to be above, and flush with, the outer layer of foam. Interesting...

Learn more every day!

[Curtis Johnson]

Where you end the floor system on an ICF wall is all part of the design. Same goes for a gable roof. If you are going to sheath a gable truss with 7/16" OSB, then you would likely want the truss back that amount from the ICF wall (outer foam). With floor systems, as you said, it depends on what finish materials are used. I hardly ever do ICF only basements ... I have done a few but not that many. Most folks around here take the ICF's all the way to the roof which I think is the best way to go. Nevertheless, in the big picture, paying attention to good air sealing practices goes along way towards an energy efficient project. Lots of choices/lots of products to evaluate. I am designing mostly with Logix ICF's (used to do Arxx) ... they, as do others, also offer a one-sided or two-sided taper top as well as other form options. All of the ICF companies I have experience with have excellent design details (pdf, dwg/dxf) details you can use in your plans. You should be able to get good tech support as well. I see Nudera has been pushing their marketing pretty good lately with a number of their projects showing up in construction magazines I get (print or on-line). If you ever have any questions on ICF's, give me a call at (208) 935-1521. If I can't answer them I have a friend who is the Logix dealer for our area who is quite sharp on all things ICF.