Curbs & Adapter Curbs

Secure rooftop installs with curbs and adapter curbs that align with your commercial RTU for fast, code-ready replacements.

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Curbs & Adapter Curbs

For licensed contractors and property managers handling light commercial buildings, the right curb is essential for mounting rooftop HVAC units safely and efficiently. Our selection includes OEM-compatible and precision-fabricated curbs that elevate and seal units above the roof deck, simplify crane sets, and provide a stable, weather-resistant base-all at budget-friendly pricing.

Adapter curbs let you adapt new RTUs to existing roof openings and duct layouts, minimizing roofing work and interior rework during replacement. Model-specific transitions align supply/return openings and base rails to your current curb, so you can reuse penetrations and maintain proper airflow. Options include insulated walls, wood nailers, and taller or pitched profiles to handle drainage and snow clearance.

Sizing is driven by the unit-not efficiency ratings. Curbs do not carry SEER2 or HSPF2 values and do not change BTU output, tonnage, stages, voltage, or refrigerant. Instead, select by exact brand/model, tonnage footprint, and orientation (supply/return side). Confirm curb height and flashing details per local code and roof construction.

Whether you’re setting a first-time curb or coordinating an RTU swap, choose purpose-built assemblies compatible with economizers, hail guards, and service clearances. Most adapter curbs are built to order; lead times vary by brand and season. Standardized OEM patterns help keep projects on schedule and on budget.

Top Brands for Curbs & Adapter Curbs

Shop Daikin and Rheem OEM-compatible curbs alongside precision-fabricated solutions from McDaniel Metals. These trusted names deliver durable, model-matched curb and adapter assemblies for dependable rooftop installations.

Frequently Asked Questions

  • What is an adapter curb and when do I need one for an RTU replacement?

    An adapter curb transitions between an existing roof curb/duct opening and a new RTU footprint, avoiding reroofing when replacing different models or brands.

  • How do I match a curb to my Daikin or Rheem rooftop unit model?

    Provide the full unit model number, tonnage, and supply/return orientation. The curb is then matched to OEM submittals for an exact fit.

  • Can an adapter curb allow reuse of an existing roof opening and duct layout?

    Yes. Adapter curbs are designed to align new base rails and openings with your existing penetration, preserving the roof opening and duct connections.

  • Are these curbs field-adjustable or built-to-order, and what lead times should I expect?

    Most adapter curbs are built-to-order for the specific RTU. Typical lead times range by season; confirm availability at time of order.

  • Do I need a licensed contractor or roofer to install a curb and ensure proper flashing?

    Yes. Professional installation is required. HVAC sets the unit; a roofer handles flashing and sealing to meet code and protect the warranty.

  • What measurements are required to quote the correct curb size and orientation?

    Share existing curb inside/outside dimensions, duct sizes and positions, curb height, roof pitch, parapet clearance, and the new RTU model and orientation.

  • Are these curbs compatible with economizers and hail guards on the RTU?

    Properly matched curbs maintain clearances and openings for economizers and hail guards. Verify accessory overhangs when selecting curb height.

  • What materials and coatings are used for weather resistance and roof code compliance?

    Commonly G90 galvanized steel with welded corners, internal insulation, and wood nailers. Some models offer coatings; all are built for rooftop durability.

  • Do curbs affect SEER2, BTU/tonnage, or refrigerant selection?

    No. Curbs have no efficiency rating and don’t change capacity or refrigerant. Selection is based on the unit footprint and model match.

  • What is included with a curb order?

    Typically the welded curb or adapter assembly with insulation and nailer. Gasketing may be included; fasteners and roof flashing are by the installer.

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