Steel Shelf Angle Thermal Break

[CTSeng]

6 stories, composite floors with brick clad exterior (metal stud back-up) in a cold climate. We're detailing a brick shelf angle at each floor welded to the edge pour angle and/or beam. Done this many times in the past successfully but this architect wants to have a thermal break on the edge angle so the steel inside doesn't sweat from condensation. Any thoughts are appreciated.

 

[Lion06]

Consider bolting the shelf angle to the bent plate and providing a korolath plate as the thermal break between the two.
I've done a similar detail for beams going from outside to inside and provided an endplate moment connection with the korolath plate, but never for a brick shelf.
Maybe the bolting detail is no good because you can't use slip-critical bolts with a korolath plate (I don't think you can anyway).
Where in the detail is it transitioning from outside to inside? That is where you want the thermal break.

 

[hokie66]

Would not the flashing on the shelf angle provide the required break between the brick and the structure? I have never seen any kind of break between the shelf angle and the supporting structure, and don't think it is desirable.

 

[Mauleflyer]

I agree with Hokie66. I have done many buildings like this and never had a thermal break. Many times the angle is welded to metal stud panel and the panel is bolted to the pour stop.

 

[apsix]

Probably your best bet is using a bracket/angle system such as shown here;

http://www.halfen.co.uk/products.asp?productID=13

Thermal bridging is greatly reduced compared to fixing the angle directly to the slab edge.

 

[lkjh345]

Agree with the above.

I do brick cladded office buildings pretty regularly (architects in this part of the world seem to love brick), and I have never done, or seen, a thermal break between the brick shelf angle and the structure.

I think your architect is over thinkingthe problem.

 

[jike]

I have done many office buildings in cold climate without thermal breaks. I try to minimize the number of connections back to the structure from a cost standpoint and this will help limit the cold transfer issue.

Once in awhile you will have an inexperienced architect requesting a thermal break without understanding the structural ramifications. I know of no way to accomplish the thermal break without jeopardizing the structural integrity.

 

[Gumpmaster]

I've used bolted connections with Micarta plate as a thermal break in alaska before. I used the coefficient of friction between Micarta and steel and designed the connections as slip critical. Thermal breaks are fairly common in industrial buildings in the far north.