● ActiveHVHZ approvedLast checked Oct 21, 2026
Owens Corning WeatherLock G / MAT Granular Underlayments
Florida product approval and Miami-Dade NOA.
Check: Not for tile roofs; no recover over existing membranes; max 30 days exposed. HVHZ approval is from the Miami-Dade NOA; FL9777 is the statewide (non-HVHZ) approval.
FL #FL9777-R18
Miami-Dade NOA24-0701.03
NOA expires04/03/2028In 18 months
Approval details
- Manufacturer
- Owens Corning · One Owens Corning Parkway, Toledo, OH 43659
- Category
- Roofing · Leak barrier · Self-adhered SBS, granule or film surfaced
- Approved in HVHZ
- Yes
- Deck type
- Wood
- NOA approved
- 08/08/2024 · replaces NOA Revises NOA 24-0207.01
Official documents
PDFMiami-Dade NOA 24-0701.03miamidade.govPDFFL9777-R18 evaluation report, WeatherLock Underlayments (non-HVHZ; names WeatherLock G and Mat)floridabuilding.org
Verify on floridabuilding.org ↗Products this NOA lists
WeatherLock G · WeatherLock MAT · AC Granular · Tri-Built Granular
Quick answers
What is the FL number for Owens Corning WeatherLock G / MAT Granular Underlayments?
FL9777 (HVHZ). The Miami-Dade NOA is 24-0701.03.
Is Owens Corning WeatherLock G / MAT Granular Underlayments approved in the HVHZ?
Yes, on wood decks. The NOA expires 04/03/2028.
Public record. Always verify on the official source before you permit.