Expansion at Joint indoor/outdoor slab interface

[McGill10]

Hello
Subject: Slab on grade construction on community cetner structure in TX (hot climate).
Here my concern is the interface detail between inside and outside slab.This structure is raised 3' above the grade level and the outside cover patio area (roof but no wall enclosure)is all around the building perimeter.
he question is: Do we need an expansion joint at the interface ( shown attached sketch). I assume it does not harm to place an expansion joint,other than joint mentainance (water penetraion eventhough sealant is placed). But if not of slab cracking issues- we may omit the expansion joint.

https://files.engineering.com/getfi...64-bc78cc5a8085&file=Slab_Expansion_Joint.pdf

I would really appreciate What you suggest and your experience on such situations.
Thank you.

 

[dik]

I would put one there and either key it in or provide a small ledge (widen the exterior beam a tad, even locally. Is your soil prone to moving either shrinking or swelling?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[McGill10]

Dik, The soil under the slab will be select fill- that way I feel a little better.
[tt][/tt]
Another question on this detail: As you see the retaining wall at the outside perimeter ( retaining a 3 ft of soil). Any provision for drainage required on the wall? I am seeing 15 mil vapor barrier under the slab and think it's fine without drainage or wheep holes.
thank you.

 

[dik]

The retaining wall should be drained to reduce pressure. Over time, the wall can crack and you can get some unsightly stains on the face. I nearly always use poly under SOG. Usually 6mil, and sometimes 10mil... I've never used 15mil. In additon, the slab should be sloped to drain.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik