slabs for wood construction

[peter spellman]

Should floor slabs in simple wood-frame construction start inside the exterior walls or should the walls sit on the slabs?

[Anonymous]

An ArchiCAD question?... but slabs(joists/floor system) have to sit on walls for support right? Additionally in ArchiCAD if you have a brick veneer that wall will have to reach the next floors wall since you can't have the brick around a slab..

[Anonymous]

could be either

walls sitting on 'slab' is a more common method

but 'slab' meeting continuous external wall (balloon frame) is also quite normal

up to you



bill

[__archiben]

all depends on the external cladding material doesn't it? the 'slab' that represents the floor framing would be aligned with the outside of the wall framing (the 'core'), no? and the walls would butt up to it below and spring from it above . . .

~/archiben

[__archiben]

. . . but then you have your party walls which might sail all the way through . . .

as the man said: up to you!

~/archiben

[Rick Thompson]

Rashid wrote:
An ArchiCAD question?... but slabs(joists/floor system) have to sit on walls for support right? Additionally in ArchiCAD if you have a brick veneer that wall will have to reach the next floors wall since you can't have the brick around a slab..

What I do, which works just fine for me, is have a composite I wrap the floor slab with (10" for 2x10 and 3/4" sub-floor as an example)... just like the real thing. It has sheathing and siding/brick.. etc. I place it on a secondary layer (exterior walls misc) and have that layer off for printing since it passes through the window and door openings. This makes sections simpler since the floor slab/wall intersections look just like they should, with the sheathing and siding on the appropriate edges (obviously not where a porch might be.. etc). This way you build the model as you would build the real building... walls on slabs, ceilings on walls.. whatever.

The only down side I have is tweaking the material list since I end up with a category with exterior walls misc, but I add those to the main categories.

The only better solution I know of would be to have the ability to add composites directly to slab edges, but that's a long standing wish.

[Anonymous]

What we've done (successfully, I think) after trying multiple methods is "draw it as it's built". That means the slab extends to the edge of the stud/ sheathing or any other such normal location. Then the walls at the exterior run all the way to the top of the slab and come section time, just SEO (or mask) the intersection (subtract slab from wall below).

This allows for:
1. Seamless exterior for elevations, and normal cuts in slab (material wise).
2. No worry about an additional wall on a hidden/construction layer.
3. Easier updates if floor elevations and/or wall heights change.
4. etc.