Introduction
When installing or upgrading the decking under your roof, two popular options are oriented strand board (OSB) and radiant barrier.
But OSB vs radiant barrier have key differences in cost, performance and installation that impact their suitability.
Here’s an in-depth comparison of using either as roof decking.
OSB Delivers Structural Support at a Cost
OSB roof decking consists of compressed wood chips and adhesives formed into solid 4’ x 8’ structural panels.
As the substrate directly under roof rafters, OSB provides:
| Property | Performance |
|---|---|
| Shear Strength | OSB rated for loads up to 2,500 lb/ft2 |
| Impact Resistance | Withstands hail, falling tools |
| Moisture Protection | Waterproof resins resist swelling |
“We used 7/16” OSB for the roof decking – it’s sturdy enough to walk on while shingling without any give. OSB stands up to weather just as well as plywood at a lower cost.” – Lee D., roofer
The price of OSB ranges from $15-30 per sheet, with additional charges for delivery and labor. For a 1,500 sq ft roof, costs tally:
| Item | Cost |
|---|---|
| OSB Materials | $2,250 |
| Delivery | $300 |
| Labor | $1,200 |
| Total | $3,750 |
So while OSB has structural strengths, prepare to pay more upfront. Long 50+ year warranties mean panels likely last as long as the roof itself.
Radiant Barriers Offer Budget-Friendly Heat Protection
Radiant barriers for roofs contain a thin, reflective foil layer that blocks up to 97% of solar radiation. As an alternative for decking, key qualities include:
| Factor | OSB Roof Deck | Radiant Barrier |
| Cost (1500 sq ft) | $3,750 | $300 to $600 |
| Installation | Professional | DIY Friendly |
| Lifespan | 50 years | 10-20 years |
So radiant barriers deliver substantial energy savings at a fraction of the price. While durability lags OSB, the lower cost makes replacing the barrier over time affordable.
OSB vs Radiant Barrier
Beyond upfront and ongoing costs, how do OSB vs radiant barriers compare across other performance factors?
Structural Strength and Support
- OSB rating: Up to 2,500 lb/ft2 rating
- Radiant barrier: Needs solid substrate; no rating
Winner: OSB for shear strength and weight bearing
Weather and Water Protection
- Equal moisture resistance with waterproof resins (OSB) and foil layer (radiant)
- OSB hides imperfections; radiant barrier shows through
Tie for weatherproofing ability
Temperature and Heat Control
- Radiant barrier deflects up to 97% of solar heat
- OSB has R-1 insulation capability
Winner: Radiant barrier for energy savings
Additional Factors: Fire Safety, Eco-Impact, Warranties
Beyond the core performance differences, a few other considerations:
So both options align with green building standards. OSB offers better long-term guarantees, while radiant barriers simplify future swaps.
How To Decide What’s Best: OBS vs Radiant Barrier
Choosing between OSB vs radiant barrier under your roof depends on whether structural integrity or energy efficiency matters most.
OSB roof decking is stronger, more durable, and moisture-resistant while meeting fire safety codes. But higher materials and labor costs take a higher investment upfront.
Radiant barriers deliver substantial summer cooling by blocking up to 97% of solar heat gain for a fraction of the price.
But as thin, reflective layers under the roof, they require solid decking support rather than providing it.
Ultimately, factor in lifespan, performance needs, and budget when deciding between OSB’s sturdy support or a radiant barrier’s heat savings.
Conclusion
OSB roof decking and radiant barriers take very different approaches to protect and enhance roofs. OSB provides durable, structural decking capable of bearing loads, weather, and time.
Radiant foil layers offer affordable summer cooling by blocking solar heat gain. Factor your climate, budget, and needs like entertaining weighty crowds on the roof deck.
OSB brings 50-year reliable support at a higher cost, while radiant barriers judiciously conserve energy for lower investment. Ultimately choosing the best roof deck system means weighing strength against heat savings.
FAQ’s
Is radiant barrier roof decking worth it?
In hot, sunny climates, radiant barrier can lower peak attic temperatures by up to 30°F. For just $300-600 compared to $3,750 for OSB on a 1,500 sq ft roof, this energy savings can justify the cost.
What is the downside of radiant barrier?
The foil layer tears easily if not protected and warranted for only 10-20 years. Reflective surfaces also hamper solar panel efficiency. As a thin membrane, it requires additional decking support rather than providing shear strength itself.
Is OSB good for roof decking?
Yes, OSB makes excellent structural roof decking able to bear heavy snow loads, high winds and foot traffic during roofing projects. It resists moisture, swelling and cracks better than cheap plywood. Warrantied to last 50+ years, it’s a sound long-term decking investment.
Does OSB with radiant barrier work?
While less common than foil barriers, some manufacturers like LP Building Products make OSB infused with reflective backing. This combines sturdy decking with heat resistance. The OSB side goes down securing rafters, while the radiant side reflects sunlight upwards.
What is the R-value of OSB?
OSB alone has an R-Value around R-1 per inch. Adding rigid foam insulation under OSB is recommended to achieve a combined R-30 insulation value meeting code minimums for roof decks in most climate zones.