Monolithic slab foundation with exterior rigid insulation

[djhplanning]

Can anyone suggest how to add rigid insulation to the exterior of my monolithic slab foundation?  I want 2" rigid insulation around the perimeter of my thickened edge slab and be flush with the exterior wall sheathing.  (Frost protected shallow foundation)  My slab edge thickness will range from 12" deep to 24" deep because of a slightly sloped site.  I want to 2" insulation to show on the foundation plan.  I have the slab edge showing with a solid line and the footing with a dashed line ok but just can't figure out the best way to show the 2" rigid as well.  I have tried also to set up a wall type that has the insulation but maybe I am not doing that correctly.  It seams like there should be an option through the build foundation dialog that you could add exterior insulation if you want.  Any help would be appreciated.

[Alaskan_Son]

Might be a better way, and its not a condition I've ever had to draw up, but what comes to mind is to set the foundation offset for your main walls to the width of your insulation then go down to the foundation level, select the Exterior Room, Make Room Molding Polyline, and then make the molding the height and width of your insulation.

[jbaehmer]

I agree with Michael - I have had a similar situation and did exactly what he said.

[justmejerry]

Draw it without monolithic slab.Try a regular concrete stem wall with 2" insulation layer. Set foundation to 24" and no footing checked on wall. Set floor to 4" concrete instead of joists and 0 for room height in foundation room structure. You will have to make two adjustments in section view. 1. slab will go over top of insulation - just drag polyline back after auto detail. 2. you will not have chamfer showing - just adjust polyline to show this after auto detail. You can set your wall lines to be dashed in wall dbx if you choose to show more accurately.

 

[glennw]

I can get this:

 

or this:

 

with an auto mono slab.

The first one has the footing under the insulation.

The second one doesn't have the chamfer.

[DRAWZILLA]

Just add it to your foundation wall definition, and use that wall in your mono slab, here in California it required unless you can make it up somewhere else using the computer method of calculations.

[glennw]

Just add it to your foundation wall definition, and use that wall in your mono slab, here in California it required unless you can make it up somewhere else using the computer method of calculations.

 

Perry,

That gives you my first pic.

You get the insulation on the foundation wall. but you can't get the insulation on the footing.

And you can't reduce the height of the footing to anything less than 100mm (about 4"), which gives you the footing under the insulation.

[DRAWZILLA]

Your right Glen, I haven't done it b/c ,here we never use the perimeter mono slab insulation, we make it up in a multitude of ways in the Calcs. No one around here really want to add the insulation at that spot b/c you can see it and weathers very badly and looks bad, and too much trouble. You would think that would work though.