What are the underlayment requirements for a metal roof in Georgia?
Short answer. Under the residential code Georgia enforces, metal roof panels and metal shingles need an approved underlayment, such as code-listed felt, synthetic or self-adhered sheets, applied with the specified laps and fastened enough to stay in place until the metal goes on, with stricter fastening only in high-wind zones. The panel manufacturer's instructions add their own requirements, often high-temperature products, and most of Georgia does not require an ice barrier at the eaves.
Code basics
- Approved materials: the code lists acceptable standards for felt, synthetic and self-adhered underlayments, and the product label should cite them.
- Application: laid shingle fashion from the eave, with the horizontal and end laps the code and manufacturer specify.
- Fastening: enough to hold it in place in most of North Georgia; where design wind speeds reach the code's high-wind threshold, a grid pattern with cap nails applies.
- Ice barrier: required only where the local jurisdiction designates a history of ice damming at the eaves. Most of Georgia does not, though it is worth asking in the mountain counties.
Georgia's code edition
Georgia moved to the 2024 International Residential Code with state amendments on January 1, 2026, and local building departments issue reroof permits and inspect. Rules and inspection practices vary by city and county, so ask yours.
Manufacturer requirements
Panel makers often require high-temperature underlayment, specific laps, slip sheets under certain metals, and solid decking beneath their panels. Their warranties depend on following those details.
Low slopes
Low-slope metal roofs benefit from, and many manufacturers require, a self-adhered membrane over the full roof.
Practical checklist
- Get the panel maker's installation guide for your profile.
- Confirm the underlayment product and the standard on its label.
- Ask the building department about permits and local amendments.
- Make sure valleys, penetrations and wall intersections get membrane.
See roofing permits in Georgia and ice and water shield in Georgia.