Do I need ice and water shield on my roof, and how much?
What the code says
The International Residential Code requires an ice barrier at the eaves only in areas with a history of ice forming along the eaves, as designated by the local jurisdiction. Where required, it runs from the roof edge to at least 24 inches inside the exterior wall line. Check with your local building department, especially in the North Georgia mountains.
Where Georgia roofs need it anyway
- Valleys. Two slopes dump water into one channel, and debris like pine straw slows it down.
- Chimneys, skylights and walls. Flashing details are where most leaks begin.
- Pipes and vents. A patch around each penetration backs up the pipe boot.
- Low-slope sections. Porch roofs and shallow transitions drain slowly.
- Eaves on shaded or problem roofs. Optional, but helpful where gutters overflow or ice can linger.
How much to plan for
Most rolls are about 3 feet wide and cover roughly 200 square feet. Add up the valley lengths (one full-width sheet each), the roof-to-wall lengths, a patch for each penetration, and the eaves if you include them, then add 10 to 15 percent for laps and waste. Manufacturers may also require leak barrier in certain locations for their system warranties. More detail in ice and water shield in Georgia and roof flashing explained.