Custom rooftop curb adapters
Rooftop Unit Transitions
Custom fabricated curb adapters and duct drops for matching new rooftop equipment to existing curbs, duct openings, and roof conditions.
- Used for RTU changeouts, equipment replacements, curb height changes, duct drops, duct opening shifts, and field condition corrections.
- Built to released curb dimensions, unit base dimensions, supply/return openings, duct drop details, height, pitch, and transition requirements.
- Confirm existing curb size, new equipment curb rail layout, duct openings, roof pitch, and installation responsibility before release.
MaterialG90 Galvanized Steel
Gauge range20 ga - 10 ga
UseRTU changeouts
Construction Standard
| Application | Custom curb adapters and duct drops for rooftop equipment replacements, curb-to-unit transitions, supply/return opening changes, height adjustments, and rooftop HVAC coordination. |
| Material | Galvanized steel is standard unless another material, coating, or finish is listed on the quote. |
| Construction | Adapters are fabricated to released dimensions using formed galvanized panels, welded or mechanically joined corners, internal dividers, top rails, bottom flanges, transition panels, and included gasket as required. |
| Dimensions | Existing curb outside dimensions, new unit rail dimensions, adapter height, duct openings, offsets, and roof pitch should be confirmed before fabrication. |
| Openings | Supply, return, economizer, exhaust, relief, duct drop, or blank-off openings can be coordinated from drawings, curb templates, or verified field dimensions. |
| Coordination | Adapters are built from approved drawings, sketches, templates, or field measurements. Equipment selection, roof structure, waterproofing, and installation are by others unless quoted. |
| Quality check | Curb adapters receive visual inspection before release. Structural engineering, load certification, field fit, or roof warranty acceptance are by others unless quoted. |
Build Quality
Made to specBuilt to released curb, unit, opening, and height dimensions.
Built toughFormed galvanized construction with reinforcement as quoted.
Quality checkedAdapters receive visual inspection before release.
Changeout readyBuilt to help new equipment fit existing curb conditions.
Fabrication Capabilities
| Adapter bodies | Rectangular curb adapters, transition bases, stepped adapters, raised adapters, duct drops, equipment changeout curbs, and custom field-fit adapters. |
| Transitions | Offsets, tapered sides, pitch corrections, supply/return shifts, duct drops, blank-off panels, and duct opening transitions. |
| Openings | Supply, return, exhaust, relief, economizer, duct drop, drain, access, or service openings can be fabricated when shown or quoted. |
| Reinforcement | Internal dividers, braces, bearing rails, top frames, bottom flanges, tabs, brackets, and special support details when requested. |
| Shop details | Wood nailers, insulation, gasketing, closures, seams, labels, piece marks, and shipping splits as quoted. |
| Release support | Built from released dimensions, templates, sketches, field measurements, or drawing packages with installation responsibilities clearly identified. |
Build Options
Adapter heightCustom heights can be fabricated to coordinate curb clearance, unit base requirements, and roof conditions.
Top frameTop rails, flanges, bearing surfaces, included gasket, or equipment rail layouts can be built to match the new unit.
Bottom fitBottom flanges, returns, pitch details, and existing curb dimensions should match verified field conditions.
InsulationInsulated curb adapter construction can be quoted when thermal, acoustic, or condensation control is required.
Adapter Options
Changeout
Old curb to new unitAdapters to match replacement equipment to existing curb conditions.
Duct drops
Air openingsSupply, return, relief, or exhaust drops coordinated to the curb and unit.
Pitch
Roof correctionSloped or tapered adapter details where roof pitch or curb condition requires it.
Insulated
Thermal controlInsulation, liners, or closed sections when specified and quoted.
Optional Accessories
InsulationInsulated panels, liner, rigid insulation, or closed sections where specified.
Included gasketGasket is included for standard curb adapter coordination unless a different seal detail is specified.
Wood nailerWood nailers, top rails, or roof attachment details when shown.
Custom detailsDividers, blank-off panels, access openings, tabs, brackets, labels, and piece marks.
Required for Quote / Release
- Existing curb outside dimensions, new equipment rail/base dimensions, adapter height, and quantity.
- Approved drawing, sketch, equipment submittal, curb template, or verified field dimensions.
- Supply, return, exhaust, relief, economizer, duct drop, drain, or blank-off opening locations and sizes.
- Roof pitch, curb condition, insulation, gasketing, wood nailer, reinforcement, and attachment requirements.
- Material, coating, load/engineering requirements, shipping splits, piece marks, and inspection requirements.
Not Included Unless Quoted
- Installation, hoisting, rigging, roofing, roof penetration work, anchoring, or field fastening unless quoted.
- Engineering, structural calculations, permits, inspections, roof warranty coordination, or listed-system certification.
- Equipment selection, load verification, field waterproofing, sealant, hardware, startup, or rework from changed release dimensions unless quoted.
Scope & Responsibility
Code note: Curb adapters may be governed by equipment submittals, project specifications, roof warranty requirements, structural requirements, mechanical code, local code, and AHJ direction. Empire fabricates adapters to released dimensions and quoted scope; final equipment selection, load path, roof attachment, waterproofing, structural approval, installation method, and field acceptance remain the responsibility of others unless expressly included.
Ready to Quote?
Let's get your duct package moving.
Send drawings, sketches, photos, or field measurements. Empire is ready to go to work for you.
quotes@empiremetalproducts.com
602-424-9980