COLUMN BUILDING SCIENCES As Per Structural, e.g., 36 in. to 48 in. o.c. FIGURE 10 Relieving Angle Thermal Bridging. Typical steel stud construction on a concrete frame with relieving angles welded to slab edges are huge thermal bridges. Such relieving angles often go completely around the building. Adding continuous insulation reduces the thermal bridging of the steel studs but does not address the thermal bridging of the relieving angle. Weld Cast-In Plate Concrete Slab Exterior Grade Sheathing Cavity Insulation Optional (Dependent on Climate and Type) Water and Air Barrier Lapped Shingle Fashion (Or Liquid Applied) Concrete Block Gypsum Board Closed-Cell Spray Polyurethane Foam All Around the Floor Slab Metal Defl ection Steel Studs Tracks Insulation Retention Washer Adjustable Tie Steel Drip Flashing (Optional) Flexible Self-Adhered Membrane Flashing Steel Shelf Angle (4 in. × 4 in.) on Steel Stand-Offs FIGURE 12 Continuous Exterior Insulation. The " stand-off " allows insulation to run past the relieving angle in a continuous manner. edges are huge thermal bridges. Such relieving angles often go completely around the building. Adding continuous insulation reduces the thermal bridging of the steel studs but does not address the thermal bridging of the relieving angle. The best way to deal with relieving angles is to hang them off of the building with a " stand-off " (Figure 11) and then spread them out every second or third fl oor. The stand-offs can be welded to plates cast into slabs or welded to structural steel supports. This allows insulation to run past the relieving angle in a continuous manner (Figure 12). Similarly, lintels supporting brick over punched openings should be held away from the structural " back-up " wall assembly allowing the insulation to be Flexible Membrane Loose Lintel Sealed End Dam Metal Flashing Window Frame as Air Barrier Hat Channel Clip Anchor Screwed to Stud to Minimize Water Leakage and Thermal Bridging FIGURE 11 Relieving Angle " Stand-Off. " The best way to deal with relieving angles is to hang them off of the building with a " stand-off " and then spread them out every second or third floor. The stand-offs can be welded to plates cast into slabs or welded to structural steel supports. Adhesive Masonry Veneer, Stone or Precast Water Resistant Barrier (Drainage Plane) Rigid Insulation Air Space Flexible Transition Membrane Overlap 6 in. Over Water Resistant Barrier and Adhered to Metal Flashing min. 2 in. Upturned Membrane Beyond Jamb to Form End Dam Weep Holes at 24 in. o.c. Prefi nished Metal Flashing with Drip Edge 0.75 in. Min. Continuous Sealant Beads Below Metal Flashing Flashing Termination Continuous Sealant Beads Below Metal Flashing FIGURE 13 Controlling Lintel Thermal Bridging. Lintels supporting brick over punched openings should be held away from the structural " back-up " wall assembly with " stand-offs " allowing the insulation to be continuous. continuous (Figure 13). Time to get serious about this thermal thing-the heat is on-don't want to get " Frey'd. " # #Glen Frey sang " The Heat Is On " for the fi lm " Beverly Hills Cop " (1984). Note that the Toronto Maple Leafs fi nished last in the entire NHL that year. J A N U A RY 2 0 2 2 ashrae.org ASHRAE JOURNAL 45http://www.ashrae.org