What are the material options for roof decking?
Short answer. The main roof decking options are OSB and plywood sheathing, which cover nearly all modern Georgia homes, plus solid board decking on older houses and tongue and groove boards for exposed ceilings. Specialty choices include radiant barrier sheathing, integrated water-resistive panels, fire-retardant treated plywood and insulated nailbase.
The common two
- OSB (oriented strand board): wood strands pressed with resin into large panels. Consistent, affordable and widely used. Its weakness is edge swelling when it stays wet.
- Plywood: thin wood veneers glued in cross layers. It usually costs more, tends to recover better after getting wet, and many roofers prefer how it holds nails. CDX is the typical grade.
Older and traditional decks
- Board or plank decking: 1x6 or 1x8 boards on older homes. Often still sound, but gaps between boards can be too wide for shingles, so sections may be overlaid or replaced.
- Tongue and groove boards: thicker interlocking boards used where the underside is exposed, such as porches and vaulted ceilings with beams.
Specialty panels
- Radiant barrier sheathing: OSB with a foil face toward the attic that reflects radiant heat. Useful in hot Georgia attics, though it does not replace ventilation.
- Integrated water-resistive panels: sheathing with a factory coating and taped seams that adds a layer of water protection.
- Fire-retardant treated plywood: used where codes call for it, such as near shared walls in some attached homes.
- Insulated nailbase: rigid foam bonded to a wood top layer, for roofs with no attic.
How to choose
For a reroof, the choice is usually about repairs: replace damaged sheets with the same thickness as the surrounding deck. For new construction or a full redeck, compare OSB and plywood on cost and moisture tolerance, and consider radiant barrier panels if your attic runs hot.
See OSB vs plywood roof decking and attic heat and shingles.