A roof replacement encompasses more than just the shingles on your roof. When it’s time to get a new roof, you are replacing your entire roofing system. This includes every aspect of your roof, including ventilation, pipe boots, flashings, and several other components.
At AIC Roofing, we take pride in helping homeowners stay informed so you can make the best decision for your home. It’s important to understand each part of your roofing system and know exactly what you’re paying for during a roof replacement. By the end of this article, you’ll know more about roof decking, when to replace it, and what red flags to watch for when choosing a roofing contractor.
What is Roof Decking?
Under the shingles of your roof, sheets of plywood or OSB sheathing form your roof deck. Think of your roof deck as the foundation of your roof. Your roofing system relies heavily on your roof deck because contractors install and nail shingles directly to it. Your roof deck helps your shingles properly protect your home against UV rays, wind, water, and ice.
When a contractor replaces your roof deck with new plywood or OSB sheathing, this process is called redecking. Redecking allows contractors to install shingles correctly and helps your roofing system perform at its best.
When is Redecking Necessary?
Redecking is not required for every roof replacement. If your home is only on its first or second roof replacement, it’s unlikely you’ll need to replace all of the roof decking. Still, you may need to swap out a few boards, especially if your home is older. The more time has passed, the more wear you can expect. Your roofing contractor will check the condition of the decking once they remove the old roof and can then determine how much needs to be replaced.
Before your roofing contractor can start installing your new roof, the decking must be repaired if they discover any rotten boards. This is done in compliance with all applicable Kentucky state codes and regulations However, if your contractor determines that the integrity of your decking is sound, it can support your new asphalt roof.
Let’s examine when redecking is necessary, and how to navigate the process with your contractor.
Redecking will be necessary for your home:
1. If Your Home is Older and Undergoing its Third, Fourth or Fifth Replacement
Every time a home undergoes a roof replacement, each 4×8 sheet of plywood or OSB sheathing incurs between 115 and 175 nail holes. This means that the sheathing of houses built between the 1960s and the 1980s may have 300 to 500 nail holes per sheet! This roof decking has become too damaged to support new nails for another new roof. This wood is more like swiss cheese than wood! To remedy this, a contractor removes the old plywood or OSB sheets from the roof sheathing and replaces them with new ones. This creates a surface that is smooth and secure for securing roofing material.
2. Dry Rot is Present
It’s simple physics that hot air rises. Improperly vented attics can get very hot during the central Kentucky summer, often surpassing 170 degrees Fahrenheit!
These extremely hot attic temperatures result in a number of issues that compromise the strength and aesthetics of your roof. Mainly, it causes a thinning and warping of the OSB Sheathing or plywood on your roof deck. If an attic space has been improperly ventilated for several years the chances of a full redecking being necessary increase significantly due to the wear of the sheathing. Occasionally, dry rot can be so severe that a roof appears wavy and sagging when looking at it from the street. Even when the ventilation issues are corrected, if the plywood or OSB sheathing is not replaced, the integrity of your roof will be compromised.
Dry rot weakens the plywood and, in some cases, renders the decking completely unusable. We would recommend not only redecking your roof but also ensuring any ventilation issues are resolved – to ensure this issue doesn’t happen in the future. Replacing your roof and especially replacing your roof decking should be a rare occurrence.
It’s important to understand the different types of ventilation options. Some options may be more expensive, but their performance is so superior it would take fewer of the expensive vents to achieve the same effect, making prices more comparable.
3. Thin Plywood
Years ago, home builders used thin, 3/8” plywood over 24” rafters. This plywood will start to sag in between the rafters because it is simply too thin to properly hold the weight of the shingles. On these homes, the roof appears wavy. To remedy this, we remove these sheets of plywood and replace them with a thicker board that can accommodate this wider span and ensure your new roof starts out on the right foot. If you believe this case applies to your home – you should contact us today about a free roof inspection.
How Much Does Redecking Cost?
It’s tough to give an exact cost for replacing your roof decking because wood prices change often. The total also depends on how many sheets of plywood or OSB need replacement. The more material required, the higher the cost.
When you redeck a roof, you’re paying for both materials and labor, including the removal of damaged decking, installation of new boards, and proper disposal.
Your roofing contractor can’t give a full estimate until they remove the old shingles and inspect the roof deck for damage. After that, they can calculate how much material the job will take.
Red Flags
Prior to hiring a roofing contractor, it’s important to ask their opinion on the condition of your existing roof decking. Some roofing contractors may purposely undercut the competition on price by omitting this issue. This leaves you with a faulty roof or a surprise bill at the end of the project.
If severe dry rot is present or if your roof sheathing is too thin to accommodate the width of your rafters – an experienced roofing contractor should be able to express these concerns prior to the start of your roof replacement. If a contractor suggests redecking in the middle of your roof replacement, it’s OK to be skeptical, but this doesn’t necessarily mean something underhanded is happening- just ask questions. Redecking is a large investment and is critically important to the longevity of your home.
If you are in doubt that your roofing contractor is being honest, ask them for pictures of the damage. In today’s world, they should be able to easily showcase any damage they have discovered. At AIC Roofing, if we find an issue that was not obvious during our initial evaluation, we typically show our homeowners photos, so they can best understand what is happening on their roof.
Learn More About Your Roofing System
Roofs are expensive. The consequences of choosing to not re-deck your roof can be severe. If you’re installing new shingles on compromised decking – your roof will definitely not reach its full lifespan, and it could visually look bad. If new shingles are nailed into compromised sheathing, your roof may appear wavy and sagging in areas. Neglecting your roof deck also puts your shingles at risk of actually sliding off your roof in severe weather or wind. This would be a disaster after making such a significant investment in your home.
According to the National Association of Realtors Research Group’s 2022 Remodeling Impact Report, a roof replacement has a 100% return on investment. That means that typically every dollar you spend on your roof increases the value of your home by the same amount. It’s important to treat your most precious asset with the care it deserves!
In order to make sure you’re getting a great price on your roof replacement, we also recommend getting multiple bids from top-rated roofing companies in the Central Kentucky area. We outline tips on how to select a reliable contractor and make an apples-to-apples comparison across your roofing bids.
Roof decking is just one of the pieces that make up your entire roofing system. We created our Learning Center and YouTube channel, to help homeowners feel knowledgeable about each part of their roof and help answer important questions about the roofing process.
Final Thoughts
AIC Roofing has replaced over 10,000 roofs in the Lexington, Louisville and Richmond, KY area. We are in the top 2% of roofing contractors in North America that received the GAF Master Elite Certification. Working with a GAF Master Elite certified contractor should give you peace of mind that you’re working with an experienced roofer that has undergone rigorous training. Along with our GAF Master Elite certification comes an extended material and craftsmanship warranty. We renew this certification every year as part of our commitment to excellence.
We don’t cut corners on your roof replacement and pride ourselves on our best-in-class customer service and experience. If you’re preparing for a roof replacement or would like a second opinion – only trust your home to the best. Contact us today for a free estimate on your roof.