Tips For Finding and Repairing Roof Deck Damage Before Restoration

Western Colloid Damaged Roof Decks
March 31, 2023 at 6:00 a.m.

By Western Colloid.  

Fluid-applied roof system experts share their secrets to repairing roof deck damage without a complete tear-off. 

When you’re ready to apply a fluid-applied roof system on an existing roof surface, it’s imperative that you determine if there is deck damage underneath. But how do you know if you can’t see it?  This is a common question we at Western Colloid hear all the time from consultants, building owners and contractors. The traditional practice has been to tear off the old roof, but not only is this wasteful, it can add additional labor costs to the project. In many cases, deck damage exists only in small areas or pockets and can simply be repaired prior to restoration. Our experts share how to find damaged deck areas and what to do about them.     

There are in fact several ways to find out if you have problems with a roof deck. First, in the Western United States, roof deck construction is typically made from plywood decks, and those become soft and spongy when the deck underneath is damaged. When you or an inspector walks a roof for an evaluation, you should easily see the roof deflections and ponding areas; this will help you determine if the deck is soft underneath.  

Another method is to inspect underneath the deck for leaks from the interior of the building. This helps you or your roofer pinpoint the location of the leaks and narrow down where the damage is going to be.  There is another method preferred by specifiers and consultants, to either fly a drone over or do some moisture testing. This is ideal but not always available.  

Your roofer could also take a core cut sample that exposes the entire history of the roof. This allows inspection of specific areas without tearing too much of the roof off. Your roofer can do isolated core cuts around a suspected problem area, then they can evaluate down to the deck. After that, it's a matter of opening more of the roof up to inspect the extent of the damage.  

A good place to always inspect are the areas around drains and penetrations. These are common areas to have deck damage problems. If you do find deck damage, it’s normally a small area of a large project such as five or six squares out of a 200 square project for example.  

A good contractor can open up a damaged area and if there's two or three squares of soft deck that need to be replaced, they might open up four or five around it to make sure everything is isolated.  They will replace the deck with the appropriate decking material and then go back with a similar membrane and make it watertight. Then, the new fluid-applied membrane is installed over the whole roof system.   

It's a little different on concrete decks and metal decks that you find in wet weather areas such as the Midwest and East Coast. Metal decking, for example, can be repaired, even heavy gauge metal decks. Once isolating the damage, a metal deck contractor can replace the damaged areas.  

About 10 percent of the time a roof has been soaking up water with rotting wood or metal corrosion for 30 years. If this is the case, the contractor will have to tear it off and put something else on. Every roof cannot be saved, but about 90% can be repaired and restored.   

Keep in mind there may be wet insulation issues. Certain insulation can hold water that can be replaced, or in some types of insulation, you can add a vapor relief vent, which allows it to dry out. In the west where there are wood decks, they tend to dry out over the period of the summer. This is because there's a lot of air movement and moisture that can be drawn away through the wood and evaporated through the structure. This will all depend on what type of insulation you find when you do a core cut and whether or not it’s going to hold in water.  

Whoever is working on your roof must be experienced, and part of that includes working with a quality contractor who knows what they're looking for. If they don't, Western Colloid is here to help. A great contractor is one who's comfortable looking at a roof and evaluating it. They understand that a roof isn't just what you see on the surface. There's so much more to a roof.  

This is a large part of what our Western Colloid technical support people do. They're out there every day walking roofs with contractors, consultants and building owners, looking to see if it's a candidate for restoration.   

It's always a great solution to restore the roofs when you can. It reduces waste and keeps it out of the  landfill, and more importantly, it saves the building owner thousands of dollars. Our President Greg Hlavaty has a great analogy: “We don't tear up our floors and replace them. We refinish them, we recondition them, or we recover them. Your roof can be the same thing.”    

Please contact Western Colloid about your next project and let our experience and expertise advise if your roof can be saved!  

Have a question? AskARoofer.  

Find your local roofing contractor in the RoofersCoffeeShop® Contractor Directory.

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