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Roof Installation

The Basics of Roof Decking

September 22, 2021 | 5 min. read

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If you need a new roof or are thinking of making a cosmetic change to your home, research will lead you to believe that roofing is complicated. Roofs have layers -a lot of them.


All of the fancy names and jargon can be frustrating. It gets in the way of truly understanding the roofing process. When you’re making such a vast investment in your property, you deserve to know what is going on. 


With a decade in the roofing industry, we have seen every sort of decking scenario. We know everything there is to know about decking, and we’re here to teach you all of the technical terms. Then they will no longer get in the way of fully understanding the roofing process.


We are often asked: What is decking? How much does it cost? What are the basics of decking? 


In this article, we will be answering those exact questions. This way, you’ll seldom be surprised with any common decking problems that arise in the roofing process.


What is Roof Decking? 


Your roof isn’t just decked out in shingles. If it were, you would have a ton of issues with leaks and storm damage.


Your roof is equipped with many layers that keep your home protected. Shingles protect all of the under layers, the ice and water barrier helps to keep ice and water out. But your decking serves a mighty purpose: it sets the foundation for the rest of the roof’s layers to lay upon.


Just like your floors have subfloors, your roof has a sub-layer that everything else is attached to. Without it, materials would simply fall into your attic space. 


The decking in most houses consists of either plywood or OSB (oriented strand board). These are the most common within the roofing industry, but if a customer is very specific about what material they want, they can discuss it with their future roofer. 


How Much Does Decking Cost?


When you begin to talk about a new roof with your roofing contractor, they will give you an estimate. Many aspects of this estimate, like the cost of demolition and the dumpster, are set in stone.


However, there is one component of the estimate that can make the price fluctuate: decking.


Because roof inspectors cannot tear away pieces of your roof during the inspection, there is no way to see the extent of any water damage underneath all of the shingles.


Inspectors can get a pretty good idea of how much decking will need to be replaced by looking in the attic space, but that is still no guarantee. Once the roof installation begins, they may find more damage than they had anticipated.


If this is the case, you will be paying for additional decking materials. And depending on the amount of damage, you may have to cover the costs of re-decking your entire roof. However, in Rescue My Roof’s experience, this is a rare occurrence. 


Unfortunately, there is no set cost for wood materials. With the COVID-19 pandemic and supply shortages, the price of wood has gone up drastically, and that price reflects onto the customer.


We have seen wood prices range anywhere from $20 per sheet to $60 per sheet in the midwest. If you want a better idea of what wood prices look like near you, we recommend calling local wood suppliers to get a better estimate. 


Or, you can read “How Much Does a Roof Replacement Cost?” to find out more about how materials impact the cost of your roof replacement. 


How Long Before Decking Has to Be Replaced?


Because the price of wood can be daunting, it’s ideal that if you do have to replace the decking of your home, you only have to do it once.


However, the longevity of the decking depends on many factors. Workmanship and ventilation being two of the most important.




The workmanship is important for obvious reasons: you want high-quality work done on your roof.


However, it is especially important when talking about decking. Not only do you want it to be installed properly so you don’t see any sagging in your roof, but waterproofing is also essential to maintain the longevity of decking.


The poorer the workmanship, the higher the likelihood for leaks, and the sooner you will have to replace the decking.


And unfortunately, when you have to replace that decking down the road, it’s not a simple fix. All of the shingles and underlayment will have to come off first to access it. So you may have to do a project similar to a small roof replacement. 


To avoid all of the hassles later, you’ll want to find a reputable roofing contractor to handle the job right the first time. 




Ventilation on your roof is a system of intake and exhaust vents that keep air circulating throughout your home.


The attic tends to hold a lot of hot, humid air which if left for too long can begin to cause mold and rot in your attic space and decking.


Having a good ventilation system with a proper amount of vents for the size of your household will keep this air from staying stagnant and causing problems. With proper circulation, it should keep your decking nice and dry.


If you want to learn more about the ins and outs of ventilation and how it prevents problems with decking, you can check out 7 Signs of Poor Roof Ventilation and How to Fix It.


So, How Long Does Decking Last?


By using the two standards above, workmanship and proper ventilation, decking can last the lifetime of your home.


However, if you have recently moved into a new home that is an older property, you may want to have the decking inspected. Especially if you notice signs of mold, loose shingles, and sagging in your roof. These could be signs that there is damage to the decking, and it needs to be replaced.


If you don’t notice these issues but your home was built before the 1940s, it would also be in your best interest to get an inspection. 


Older homes are more likely to have damage as they have had a longer exposure to the elements. They are also more likely to have skip decking, which requires the deck to be sheeted over to ensure every shingle can be secured to the roof decking properly. 


These issues with older homes will make it more likely that you will need new decking, so it’s best to get it checked now before you encounter leak issues later. 


What Should I Do If I Think I Need New Decking?


Now that you know all of the technical aspects of decking, it’s time for the next step: evaluate your home and determine if it’s time for an inspection.


Is your home built before the 1940s? Age alone is enough to justify an inspection. 


Have you noticed leaks? Water damage? Mold in the attic space or sagging on your roof? It’s time to call a reputable roofing company for an inspection.


While an inspection won’t guarantee a look into all of the work that needs to be done, it can give you a better idea of if the work needs to be done at all. If the inspector doesn’t find any issues with your roof, you will know you’re in the clear.


If the inspector does find issues with your roof and you know it needs a replacement, you can read the articles below to get a better idea about the roofing process and the cost. 


Read more: 

How Long Will My Roof Replacement or Repair Take?

How Much Does a Roof Replacement Cost?

If you live in the greater Milwaukee area, you’re in luck! Rescue My Roof is always scheduling inspections and estimate appointments at no cost. Do you think you might be in need of new decking? Contact us today.