Why does slab floor go THRU the stemwall? Plan file attached!

[GeneDavis]

Walkout basement plan.  At the walkout framed walls, the pony wall break, stemwall below, framed wall over, is at the rough basement floor elevation.  The floor slab, which is built as 4" concrete over 2" rigid foam, comes through the wall to coincide with the main layer outside.  How can this be controlled?  I'd like to have the floor bear INTO that wall 2" from the inside, which we can do by blocking 2" foam pieces in the wall forms before pouring concrete.

 

But I sure don't like seeing the lines in elevation, or the foam in 3D views.

[javatom]

Click on the foundation walls and change the structure to hang from wall.

[GeneDavis]

That does not work, but thanks.

 

I stripped all the trees (wow are they a space hog!) and all the fixtures and furniture from the plan, and it is attached.

Stripped.zip

[GeneDavis]

And I cannot reproduce this when sketching up a quick new simple plan.  Never seen it before in doing walkout basements, and almost everything I do has a walkout basement.

 

In the stripped file I have posted here, see above, I can make the floor behave properly by pulling (in plan view) any of the three interior walls, that butt to the pony wall (framed over stemwall), just back enough to disconnect.

 

What could this be?  See the pic attached for the walls, any one of which if separated from the pony wall, makes the floor-thru problem go away.

[HumbleChief]

Apologies in advance as I'm not sure I understand the problem completely but does this setting help?

[GeneDavis]

No.

[HumbleChief]

...or might you create a small 2" "room" around the perimeter of the basement floor and define it as you'd like?

[HumbleChief]

Gene, try adding another layer to the concrete pony wall, seems to eliminate that bleed through of the foam layer.

[GeneDavis]

I'd like not to use a workaround.  The floor needs to stop at the inside face of the wall.

 

What is the one little thing in the plan that's causing this unwanted behavior?

[Doug_N]

Gene,

 

I did a little slicing to see what was going on.  This is some sort of visual artifact and should be reported to CA support.  The floor is not being clipped correctly and if you change the floor to only have one layer of concrete, the problem disappears.  

What is happening here is a Z fight at the surface of the stem wall and shouldn't be happening at all.  A work around is to place the insulation as a slab stopping at the footings.  That is, obviously, a manual operation and is just a bit of kludgy work around, but it will work.

 

Doug

[HumbleChief]

4 minutes ago, GeneDavis said:

...The floor needs to stop at the inside face of the wall.

What is the one little thing in the plan that's causing this unwanted behavior?

Yes the floor should stop at the inside face. I think it's called a bug. Did you send it into tech support.

[GeneDavis]

I guess I'll have to.

[HumbleChief]

Gene, if you define the concrete floor as framing and 'hang from wall above ' it seems to build better/OK? Turn on auto build framing.

 

 

[SNestor]

@GeneDavis -

Not sure why you got what you got...but the fix is simple. Watch the video...very short

 

Gene Davis - Slab Floor at Walkout Basement - Watch Video

[rgardner]

1 hour ago, SNestor said:

@GeneDavis -

Not sure why you got what you got...but the fix is simple. Watch the video...very short

 

Gene Davis - Slab Floor at Walkout Basement - Watch Video

I have to concur this presents like a bug.  I didn't spend much time but after watching Steve's video and seeing what he did I went into the model.  @GeneDavis Already has the floor set correctly with the 2" insulation and regardless of setting it to detail as insulation the problem goes away once you have removed it and put it back (closing out the dbx first.)  Funny thing is that when I did that for the middle room it cleared it from the room to one side but not the other... I am sure that removing and replacing the insulation would fix that issue on the other side as well but that is something that should be taken to tech support.

 

CAVEAT:  I did this in X14 because X13 is behind us...

 

[GeneDavis]

Thanks, Steve, for the work and the video.  And thanks, Ryan, for your observations.  I sent the file in with a ticket to Chief, and I also sent them this test file, same kind of condition, which does NOT exhibit the problem.  There is something screwy in my job file.

Test floor.plan

[glennw]

Gene,

Here is another way that works.

Make this selected wall (or some other walls as well) a Furred Wall.

Why not try making those double walls as a single wall definition?

It may be worth a try.

I have no idea why changing that 1 wall to Furred effects walls on the others side of the building.  

I have also gotta ask because I don't do any walkout basements - is there any particular reason why you put a full liveable floor on level 0 and don't have a seperate Foundation on level 0 and the first liveable floor on level 1?

 

 

[GeneDavis]

Glenn, I am just following what I believe to be the conventional wisdom as re walkout basement builds.  Here is Chief's Scott showing us how.

 

https://www.chiefarchitect.com/videos/watch/51/creating-a-walkout-basement.html?playlist=101

 

Here is a file of a model I did for Chief's techs out in the support office, where I filed my ticket about this problem with my job model.  It did not exhibit the behavior, but I did not build any framed walls to fur against the foundation.  

Test floor.plan

[rgardner]

4 hours ago, glennw said:

Gene,

Here is another way that works.

Make this selected wall (or some other walls as well) a Furred Wall.

Why not try making those double walls as a single wall definition?

It may be worth a try.

I have no idea why changing that 1 wall to Furred effects walls on the others side of the building.  

I have also gotta ask because I don't do any walkout basements - is there any particular reason why you put a full liveable floor on level 0 and don't have a seperate Foundation on level 0 and the first liveable floor on level 1?

 

 

I do quite a few "Daylight" Basements as well.  I have tried both techniques and there are benefits to both but I believe it is a little faster and have had less issues with putting the basement on level 0.

 

That being said I have modeled this identical situation lots of times and never seen this happen.  With Furred walls In many cases the furred walls are not full walls as they are just to hide the partial concrete wall at the bottom half where part of the wall is in the ground.  This is generally the case to use a second wall instead of a single definition wall.  However I consistently use a second wall for entire basements with an air gap as the exterior of the wall and mark it as a partition wall and snug up against the basement walls.  The perpendicular walls continue through to the foundation wall to give room definition.  The different techniques have different issues within 3d but that technique for me has given the least amount of issues.

 

[dshall]

5 hours ago, glennw said:

.......

I have also gotta ask because I don't do any walkout basements - is there any particular reason why you put a full liveable floor on level 0 and don't have a seperate Foundation on level 0 and the first liveable floor on level 1?

 

 

 

Something I have always believed in.  Walkout basements on level 1 and the foundation on level zero.  If you do not need to use level zero,  no problem,   you can still get your model finished using all levels except for level zero.

 

Joey advocates for the walk out basement on level zero,  it seems to work for him,  but that being said,  nobody has given me a reason why putting walkout basement on level 1 does not work.