Architectural Metal Trim
Summary
Architectural metal trim is a family of aluminum, stainless steel, zinc, brass, and coated-steel profiles used as corner and edge protection, reveals, shadow lines, and transitions between finishes. Pick the profile, metal, and finish with the adjacent materials, and coordinate it with the gypsum board or tile detail so the trim is set before finishing.
Cols
Terminology
- Cornerbead: accessory that protects an outside corner of gypsum board
- Edge trim: accessory that finishes a board edge, including casing beads, bullnoses, and stops
- Control joint: accessory that allows movement in a gypsum board surface
- Reveal and shadow mold: recessed profile that creates a clean line between surfaces
- Transition profile: strip that joins two floor finishes at a change in material or height
- Movement joint profile: trim with a flexible insert for tile and flooring joints
Standards
- ASTM C1047: accessories for gypsum wallboard and gypsum veneer base, covering cornerbeads, edge trims, and control joints
- Steel accessories under C1047 must not show red oxidation after 192 hours of salt-spray testing
- AAMA 611: anodized architectural aluminum; Class I minimum 0.7 mil, Class II 0.4 to 0.7 mil
- Profile families for tile and floors include wall, floor, countertop, stair, cove, movement joint, and LVT profiles
Materials
- Zinc-coated steel and rolled zinc: drywall accessories, with zinc to ASTM B69 Type I
- Zinc-aluminum alloy-coated steel: referenced in newer editions of C1047
- Anodized or painted aluminum: reveals, edge trims, and transitions
- Stainless steel: durable and wet-area profiles
- Brass and bronze: decorative trim and nosings
- Plastic and paper-faced accessories: edges and ends in gypsum board work
Detailing
- Choose the profile before framing, board, or tile is installed, since reveals set board edges
- Set trim to the board and finish thickness so joint compound can feather over flanges
- Match the metal and finish to adjacent fixtures and hardware
- Allow for movement where profiles bridge control joints or structural movement
Uses
Specific uses
- Corner and edge protection on gypsum board
- Reveals and shadow lines at ceilings and wall junctions
- Tile edges, wall trims, and stair nosings
- Floor transitions between different finishes
- Movement joints in tile and flooring
Pros and cons
Pros
- Protects corners and edges from impact
- Gives clean, consistent lines
- Available in many metals and finishes
Cons
- Must be coordinated with board and finishing before installation
- Custom reveals add cost
Manufacturing and cost
Construction
- Profiles are roll-formed or extruded in lengths, then coated, anodized, or finished
- They are installed with fasteners, adhesive, or embedded in setting material
Main manufacturers and suppliers
Trade association: National Association of Architectural Metal Manufacturers.
Sources
- iTeh Standards: ASTM C1047 accessories for gypsum wallboard and gypsum veneer base, https://standards.iteh.ai/catalog/standards/astm/a57c24cd-91bf-45c1-a561-5bd04bd819c6/astm-c1047-19
- ASTM International: C1047 document center, https://document-center.com/standards/show/ASTM-C1047
- Schluter Systems: profile categories, https://www.schluter.com/
- National Association of Architectural Metal Manufacturers, https://www.naamm.org/