Secondary Framing
Base Angles and Base Channels for Metal Walls
Definition: A base angle is a light steel angle or channel fixed to the concrete slab edge or curb along the base of a wall. It supports and aligns the bottom of the wall panels, closes the wall at grade and helps keep water and pests out.
Key facts
- Commonly a cold-formed angle or channel, fixed with concrete anchors.
- Located at the outer edge of the slab or curb along each wall.
- Works with closures and sealant to reduce water and pest entry.
- A slab notch or step often helps shed water away from the panel base.
- Masonry dados replace base angles where walls start above grade.
Role in the structure
Wall panels are fastened at the bottom to the base angle, which transfers wind loads from the panel base into the slab. The base angle also sets the line and level of the wall, provides a surface for closures and sealant, and protects the panel edge from damage.
Why is the base angle detail important?
The bottom of the wall is exposed to splash, standing water, dirt and impact. A good base detail keeps water out of the building and away from the panel edge, which reduces corrosion and maintenance.
Common practice is to set the slab edge with a small notch or step so that the panel overlaps the concrete and water drips clear of the joint.
How is the base angle fixed?
Base angles are anchored to the slab with expansion anchors, screw anchors or powder-actuated fasteners at regular spacing. Panels are then fastened to the angle with self-drilling screws.
Anchor type and spacing depend on wind loads and concrete conditions, and should be shown on the erection drawings.
When is a base channel or masonry dado used instead?
Where impact from vehicles or forklifts is likely, a masonry or concrete dado wall is often built to a certain height, and the steel wall starts above it with a girt and trim.
Base channels are sometimes used to hold liner panels and exterior panels at the same line, or where sandwich panels need a seated base.
Materials & coatings
- Cold-formed galvanized or zinc-aluminum coated steel angles or channels.
- Concrete anchors suitable for the slab and exposure.
- Closures and sealants compatible with the panel profile.
Design considerations
- Wind loads at the panel base.
- Slab edge and notch detail.
- Drainage and splash zone.
- Impact risk and need for dados or guards.
- Corrosion environment at grade.
Fabrication
- Roll-form or brake-form angles to length.
- Supply with pre-punched holes where practical.
- Bundle by wall elevation.
Erection
- Set base angles to a true line along the slab edge.
- Fix anchors at the specified spacing.
- Install closures and sealant before wall panels.
Inspection & quality
- Check alignment and level of the base line.
- Verify anchor spacing and embedment.
- Confirm sealing at laps and corners.
What to include in your RFQ
- Slab edge detail and finished floor level.
- Dado wall height, if any.
- Wall panel and liner type.
- Exposure and drainage conditions.
3D model & IFC of this component
Rotate the model, isolate the component and download its IFC4 file for your BIM coordination model.
IFC entity: IfcMember. Illustrative geometry for coordination and learning. Final member sizes come from the project design.
Frequently Asked Questions
Who installs the base angle?
Usually the erector, after the slab is cast and before wall panels are installed.
Can base angles rust?
Coated angles resist corrosion, but poor drainage and soil contact shorten life. Good detailing and keeping soil away from the wall help.
Is a slab notch necessary?
It is not mandatory, but it is a common way to improve water shedding at the wall base.
Engineering content is general guidance. Every World Steel building is designed by qualified engineers to the code and loads of the project.
