STC Firewall Inspections (Legacy)






TO: Residential Contractors                                                                                                        SUBJECT: STC/Firewall Inspections

FROM: Building Official                                                                                                                DATE: Updated October 26, 2021


Section 113.3 of the Virginia Residential Code requires framing and insulation inspections for Sound Transmission Classification (STC)/Firewalls that separate attached dwelling units prior to installing any concealing materials.  The inspections may be requested via the Build Henrico Customer Portal at Build Henrico Log-In.   Both the Firewall Framing and the Firewall Insulation inspections require that the complete set of approved construction plans be on site for use by the inspector.

A third party “special inspection” may also be used to satisfy the required Firewall Framing and Firewall Insulation inspections.  The following conditions shall apply when using third party special inspections.

  1. The special inspections must be performed by, or under the supervision of, a Virginia registered design professional (i.e. Professional Engineer or Architect).
  2. A Firewall Framing and Firewall Insulation inspection shall be requested by the permit holder or the registered design professional no later than 7 a.m. on the day that the inspections are to be performed.  A message shall be entered on the inspection request to indicate that the framing and insulation inspections are being performed by the registered design professional and the approximate time of their inspection.  Both the Firewall Framing and Firewall Insulation inspections require that the complete set of approved construction plans be on site for use by the registered design professional.  A Residential Building Inspector or Plan Review Engineer may visit the site to audit the special inspection.
  3. The registered design professional’s report of the completed special inspection shall be filed with the Department of Building Construction and Inspections prior to obtaining a final inspection for either of the dwelling units served by the STC/Firewall.  A .pdf version of the inspection report shall be uploaded to the building permit as a supplemental document on the Build Henrico Portal. An email shall be sent to confirming that the report has been uploaded to the permit. The department will not accept photocopy or faxed reproductions of completed inspection forms.
  4. The registered design professional and contractor will be notified in the event that the inspection report is rejected.  The registered design professional’s report shall indicate the date, start and end times of the inspections.  The report shall also verify the materials used to construct the wall (e.g. studs, insulation, sheathing, fasteners, etc.), the method of construction applicable to the specified design, and confirmation that the wall was observed to conform with the approved plans.

Any STC/Firewall design that was required to be specified prior to issuance of the building permit, and was completed prior to obtaining the Firewall Framing and Firewall Insulation inspections, shall be subject to a field sound transmission test conducted in accordance with ASTM E336.  The test shall be conducted by, or under the supervision of, a Virginia registered design professional.  The test results shall confirm compliance with the STC rating specified in the approved construction documents and the Plan of Development/Subdivision approval.  The field test report shall be submitted to the Residential Building Inspections Supervisor and be approved prior to obtaining an approved final building inspection and issuance of the Certificate of Occupancy.  The ASTM E336 test procedure will not be accepted as an alternative to the required Firewall Framing and Firewall Insulation inspections for any building permit application filed on or after June 1, 2005.

Fire-rated and Sound Transmission classified floor-ceiling assemblies that are located between dwelling units will continue to be inspected during the routine framing and insulation inspections requested for each respective dwelling unit.

Please call our offices at (804) 501-4360 between 8:00 a.m. and 4:30 p.m. if you have any questions regarding these inspection procedures.

Gregory H. Revels, CBO
Building Official

Contact Us

Building Inspections

Physical Address
4301 East Parham Road
Henrico, VA 23228

(804) 501-4360
Automated Permit System
(804) 501-7770

Mailing Address
P. O. Box 90775
Henrico, VA 23273-0775

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