Continuous steel shelf angles that support brick and stone veneer interrupt the exterior insulation at every floor line. Because the angle runs the full perimeter of the building, it can be one of the largest thermal bridges in a masonry-clad wall.
A shelf angle thermal break separates the angle from the slab edge or embed with high-strength STB-1 pads or shims, reducing heat loss while keeping the veneer load path intact.
Ways to Thermally Break a Shelf Angle
- STB-1 shims at each anchor: discrete pads between the angle and the slab edge at each bolt or anchor location, with the gaps between left for insulation.
- Continuous STB-1 strip: a strip of STB-1 behind the full length of the angle where continuous bearing is required.
- Stand-off connections: the angle is held off the slab on brackets so insulation can run behind it, with STB-1 pads at the bracket-to-slab connections.
Each option trades thermal performance against detailing effort. Discrete shims and stand-offs leave the most room for continuous insulation.
Design Considerations
- Shelf angle loads are mostly vertical shear with eccentricity from the veneer, so pad bearing and bolt bending through the added grip should both be checked.
- Isolate anchors with thermal break washers and bushings so the fasteners do not bypass the pad.
- Coordinate flashing and drainage at the angle with the thermal break so water is shed outboard.
- Allow for adjustment: slotted holes in STB-1 shims can be machined to match the angle.
Final connection design, including bolt sizing, pad thickness and load checks, is the responsibility of the project’s structural engineer of record. We supply material data and fabricate to the approved design.
Supplied Ready to Install
We cut STB-1 shims and strips to length, drill or slot them to your anchor spacing and package them by elevation or floor. Standard thicknesses run from 1/4″ to 2″, and typical lead time is 5–7 days.
For spec language, see the structural thermal break specification.
Request a Quote or Data Sheet
Send us your connection drawings, bolt schedule or load requirements and we will quote STB-1, TBF, washers and bushings cut and machined to your specification. Data sheets and design support are available for engineers and architects.
Call 800-580-4195 or use the form below. STB-1 typically ships in 5–7 days; TBF in as little as 3 days.