When homeowners think about a roof replacement, most of the focus naturally goes to shingles, colors, and warranties. While those elements are important, the most critical part of any roofing system is what lies beneath the shingles. The roof decking serves as the foundation of the entire system, and if it is not properly prepared, even the best shingles can fail prematurely. At ABJ Roofing, we install 7/16 OSB over old board decking to ensure every roof we install is built to last.
What’s the Issue With Old Board Decking?
Many older homes were originally constructed using individual wooden boards as roof decking rather than modern plywood or OSB. While this type of decking was standard decades ago, it was never designed to support today’s roofing materials. Over time, exposure to temperature changes, moisture, and natural aging causes these boards to move, warp, and weaken.
One of the most common problems with old board decking is an uneven surface. As boards expand and contract, they can cup or separate, creating highs and lows across the roof deck. When shingles are installed over an uneven surface, they do not seal correctly, which can lead to early deterioration and reduced performance.
Another issue is the presence of gaps between boards. Older decking often has noticeable spacing that increases with age. These gaps can allow the roof system to flex, creating weak points that increase the risk of leaks and moisture intrusion.
Nail holding strength is also a major concern. Over time, older wood becomes brittle and may split or fail to hold nails securely. This reduces the roof’s resistance to high winds and storms, increasing the likelihood of shingle blow-offs or lifting.
Why These Issues Matter During a Roof Replacement
Installing new shingles over problematic decking does not solve underlying issues—it hides them. Without addressing the roof deck, problems such as leaks, wind damage, and premature shingle failure can develop long before the roof reaches its expected lifespan. In many cases, homeowners are left dealing with repairs that could have been avoided with proper preparation.
Roofing manufacturers also require proper decking conditions for warranties to remain valid. An unstable or uneven deck can void coverage, leaving homeowners unprotected if issues arise. That is why addressing old board decking is not just a recommendation—it is a smart investment.
Our Solution: 7/16 OSB Overlay
To eliminate these issues, we install 7/16 OSB directly over the existing board decking. This process creates a smooth, solid, and uniform roof deck before any underlayment or shingles are installed. By overlaying OSB, we provide a consistent nailing surface that meets modern roofing standards and manufacturer requirements. This step ensures the new roofing system has a strong foundation and performs as designed.
The Result: A Stronger Roof System
Installing 7/16 OSB over old board decking provides clear, long-term benefits for homeowners.
The roof installation is flatter and more uniform, allowing shingles to seal properly and look better overall. Improved nail penetration and consistent fastening increase wind resistance and help prevent shingle blow-offs during storms. Most importantly, the entire roof system lasts longer by reducing movement, stress, and premature failure.
No Shortcuts. Built the Right Way.
By addressing the roof deck before shingles are installed, we eliminate issues that can shorten the life of a roof. Installing 7/16 OSB over old board decking creates a solid foundation that allows the roofing system to perform at its best. It’s a proactive investment in strength, durability, and long-term reliability—because a quality roof isn’t just about what you see on top, it’s about what’s built underneath.
If you suspect your home has old board decking or you’re planning a roof replacement, ABJ Roofing is here to help. Contact us today for a professional inspection and expert guidance on building your roof the right way.
