Insulation (rigid) under and around a Monolithic Slab


Nigel8159
 Share

Recommended Posts

Has anyone had any experience with getting CA to place a rigid insulation layer around the perimeter and under a monolithic slab.  Under isn't as important as the perimeter is.  The layer at the perimeter affects the transition to the wall above and has an impact on the aesthetics of the exterior design (at least for the project I am working on).  Developing the CAD detail is easy enough for building permit purposes but the exterior elevations and renders won't show it making it difficult to accurately showcase the grade level transition.  I hope that makes sense.  

Link to comment
Share on other sites

I will try to post a CAD detail this evening.  I am using a Monolithic Slab system that has a 2-7/16" layer of rigid insulation around the perimeter of the concrete.  The structural exterior wall sits on the slab leaving up to a 2" difference below that will need to be capped.  I am hoping to be able to show the rigid insulation on the exterior vertical edge of the slab for the elevations and renders.

Link to comment
Share on other sites

I know that some builders don't like it but in this case I am using a system called Iso-Slab which is a rigid foam insulation form which stays in place after the pour. I will have no choice but to deal with the insulation at the edge. It creates a totally insulated floor and has some advantages for the climate here in Thunder Bay Canada. 

Link to comment
Share on other sites

You could do it with a pony wall I think, lower portion would have the 2" EPS layer or be spec'd as an ICF Wall , then add the Sheet Metal or whatever you plan to use to protect the Foam outside that.

 

Under Slab , just add the Foam to the Floor Structure Tab....

 

Please do you forum sig. as the Software version effects the Answers Given , see mine in Blue to do yours...thx

 

M.

Link to comment
Share on other sites

Mick, You are right, I use the pony wall all the time.  The OBC now requires rigid insulation outside the foundation wall in some circumstances.  The pony wall is the way to go.  That also lets you do a bubble membrane when clay or other water retaining soils are encountered.  

Link to comment
Share on other sites

6 minutes ago, Doug_N said:

Mick, You are right, I use the pony wall all the time.  The OBC now requires rigid insulation outside the foundation wall in some circumstances.  The pony wall is the way to go.  That also lets you do a bubble membrane when clay or other water retaining soils are encountered.  

 

thanks for the confirmation Doug , I don't have time this morning to play around in a Test Plan .

 

I usually spec the Delta Bubble Membrane and recommend it for all basements , since I see no point on relying solely on a sprayed on coating of bitumen or something similar. But no Monoslabs around here not even for garages.

 

M.

Link to comment
Share on other sites

Sorry gents, don't mean to be a lazy poster but with March Break starting and coaching hockey I'm swamped.  I was able to put this together in about 10 minutes so sorry for the crude line weights but I hope it will illustrate what I'm trying to do.  The Styrofoam Form is 2 7/16" thick at the vertical edge.  a 7/16" sheathing with 2" rigid on the wall system will make it about even at the outside face of the Styrofoam.  I'm not using a standard stud wall, but didn't have time to show the structural panel wall for this detail.  I am going to be using the 7.5" Greenstone Structural Solutions panels. https://www.gsbp.ca/.

 

I like the Pony wall idea and hadn't thought of that.  I will give it a try later tonight to see if I can make it do what I need.  I have also tried to activate my signature but just in case it doesn't come through I am using the CA X11 Beta right now, just changed over from X10 a couple weeks back.

Slab detail.pdf

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share