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Do You Have Rotten Roof Decking? Know the Five Signs

January 21, 2022 | 4 min. read

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Being a homeowner comes with a lot of responsibility. You are the one who will inevitably tackle any challenges or issues that arise in the home. 


But homeownership doesn’t come with a manual on every potential disaster that could affect your home. When it comes to recognizing when something is starting to go wrong, you could be lost entirely. 


Not knowing what to do in the face of the unknown is scary. Rescue My Roof has dedicated over a decade in the roofing industry to help homeowners like you. The ones who want to be actively involved with their homes to avoid future problems but don’t know where to start. 


We have educated homeowners in the Milwaukee area on how to tackle roofing issues like rotten decking – and today, we’re giving that education to you. 


We will give you the breakdown of the bank signs you may have rotten roof decking. Then we will tell you exactly what to do about it. 


In the end, you’re going to know exactly what to do when you recognize rotten roof decking in your own home. 


What is Roof Decking?


We’ll start with the basics.


Your roof isn’t just decked out in shingles. If it were, you would have many 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.


Like your floors have subfloors, your roof has a sub-layer that everything else is attached to. Without it, materials would 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. 


The Top Five Signs You Have Rotten Decking


The most common sign you will see when there is rotten decking is roof leaks. However, there are a few more things that should raise red flags as soon as you see them.


1. Sagging Roof


A sagging roof can be a sign of rotten wood deckingWhen excess moisture seeps into the wooden roof decking, there are significant consequences.


You may notice the wood in your attic beginning to warp. The boards will look wavy or bowed, like too much weight placed on them.


Additionally, as the issue worsens, you will be able to detect the sagging from the exterior of your home. 


There may be an entire section of your roof that has begun to sink lower than the rest. That is a tell-tale sign that something is wrong with the decking or the rafters.


2. Water Stains in the Attic


Water stains can be an indicator of rotten wood decking Have you taken a peek into your attic space recently? If you fear there may be an issue with your roof, that may be the first place to start looking.


When your roof decking has begun to rot, the wooden boards at the top of your attic will have water stains.


These stains typically appear as dark areas. These stains will tell you that moisture has crept its way to your decking, and it may be time to address the excess moisture before it’s too late. 


3. Mold or Mildew in the Attic Space


Mold growing in an attic space due to poor roof ventilation.
Mold growing in the attic space.

One of the issues homeowners pray they never have to face is mold or mildew growth.


When there is excess moisture in the attic space, and there isn’t proper ventilation to dry it out, it can result in mold and mildew.


You will notice the dark stains popping up all over the attic, as well as the smell of mildew. 


Mold and mildew can not only call for extensive repairs and treatment but can also negatively impact your family’s health. 


When you notice mold or mildew, rotten decking may be to blame. 


4. Roof Delamination


As we’ve said before, there are several layers of materials underneath the shingles that keep your roof water-tight.


These materials can adhere to your roof because of materials like nails and the wooden decking’s natural texture.


Rotten decking and excess moisture causes the glue to separate and the wooden boards loose structural integrity. As a result, materials will no longer stick to them (delamination).


When this occurs, You may notice missing shingles or visible flashing on your roof.


5. Roof Leaks


Decking is your roof’s last line of defense against water. And when it fails, the water will begin to come into your home.


Leaks can also be a cause of rotten decking. So when you notice a leak, it’s possible the rotting has already begun, or it has already grown severe.


What Do You Do When You Have Rotten Decking?


The only safe and reliable solution for the safety of your home is to replace the wood of areas that have been affected. 


This requires tearing off all roofing materials like underlayment and shingles to access the decking.


Professionals will then cut out the rotten boards and replace them with new wood.


This task can be daunting, especially for homeowners who do not have prior roofing experience. If you notice any signs, call in the professionals to repair the problem. 


Replacing Rotten Decking


The most important part of replacing rotten decking is not just the act of installing new decking; it’s diagnosing the underlying cause of the rot.


If an area of your roof is leaking, it’s essential that this issue is addressed so that you do not have to face these costly repairs again. 


The best way to handle any of the five signs is to call in the roofing professionals. They will send an inspector to your home to not only give you an estimate but diagnose the issue.


You can learn more about what happens at an estimation appointment with “What to Expect At Your Roof Estimation Appointment.”

Dealing with rotten decking, leaks, or need a roof replacement in the greater Milwaukee area? Contact Rescue My Roof today to get a free estimate and start your roofing journey.