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International Code Council

IMC (mechanical code)

The mechanical code governs how HVAC work is installed: duct construction and support, combustion air, ventilation rates, condensate handling and the clearances a service technician will need later.

Adoption varies by jurisdiction — confirm the edition your authority having jurisdiction enforces before you run a walk against it.

What it covers

  • Duct construction, sealing and support
  • Combustion air and flue arrangement
  • Ventilation and exhaust requirements
  • Condensate drainage and equipment access

What the evidence looks like

  • Duct sealing photographed before insulation covers the joint.
  • Equipment clearance measured in frame, ahead of the walls closing in.
  • Condensate trap and termination shot, including the primary and secondary path.

Common questions

What is IMC (mechanical code)?
Mechanical installation — ductwork, combustion air, ventilation, condensate. It is published by the International Code Council. The mechanical code governs how HVAC work is installed: duct construction and support, combustion air, ventilation rates, condensate handling and the clearances a service technician will need later.
What does IMC (mechanical code) cover?
Duct construction, sealing and support; Combustion air and flue arrangement; Ventilation and exhaust requirements; Condensate drainage and equipment access.
What does a field inspection against IMC (mechanical code) look at?
Duct sealing photographed before insulation covers the joint. Equipment clearance measured in frame, ahead of the walls closing in. Condensate trap and termination shot, including the primary and secondary path.
Which edition of IMC (mechanical code) applies to my project?
Adoption varies by jurisdiction — confirm the edition your authority having jurisdiction enforces before you run a walk against it.
Which checklists verify work against IMC (mechanical code)?
3 free checklists in the RTI library reference this family — each listed on this page with the photo evidence every item needs before it can be submitted.

A standard is only met if the evidence exists

RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.

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