When to retrofit and when to redo

By Emma Peterson. 

From building capacity to the original roof material, learn what to look for when choosing between redoing an entire roof and retrofitting it.  

Retrofitting has become a popular option in recent years. In comparison to traditional tear-offs, this option has many positive factors that owners consider favorable in the long run, such as the economic and environmental benefits of retrofitting. In this episode of Roofing Road Trips®, Roger Russ from Tremco stopped by The Coffee Shops™ to chat about the art of retrofitting and how to tell when it might be the right solution for a project.  

The first step of retrofitting is to determine if a roof is a good candidate. Rodger shared, “The very first thing you do when you're going to do a retrofit on any building is look at the existing structure. We do this to see if it has the ability and capacity to add extra weight to put that new roof system on there. A new retrofit will typically weigh anywhere from a pound and a half to maybe three and a half pounds of additional dead load. So that structure must be able to handle that existing weight and stay within the current codes.”  

That last bit about codes is especially crucial, as many roofs that are considered for a retrofit were built four to five decades ago. Being built that long ago means that the codes were probably different when they were constructed than they are today. But even if a roof doesn’t have the capacity for a retrofitted roof on top of the existing one based on the original codes it was built to meet, there are still solutions. Rodger explained, “One of the companies we work with called Roof Hugger has done extensive testing that allows us to design and add structural elements that gives a building more capacity... So, putting on a retrofit with these structural members can increase that capacity and be a huge benefit to the customer because now they're getting what they want and they're not spending tons of money trying to reinforce this structure.” 

After you figure out the capacity of the roof and if you are adding structural members, it’s time to consider the existing roof material and products. Rodger gave an example, “Quite often a roof will be designed, or a building will be built, and the roof will be installed, say with a built-up roof. One of the big issues with these roofs is that, over time, they will be compromised, and water will begin to intrude. Before you can retrofit anything, you must scan that roof and find out if it's wet.” If a roof has too many large wet patches, you can’t retrofit it.  

But let’s say you scan it, and there are a few small spots that you can repair. What’s next to consider? The details. Rodger explained, “Because you're actually attaching through a roof and typically into a different substrate or substructure, retrofitting contractors have to be acutely aware of what they're screwing into and what's beneath it. As an example, if you haven't done your due diligence, you might find electrical conduit buried in the old roof and you could easily take screw guns and long screws and be screwing into items that they shouldn't be.”  

Ultimately, the entire process of retrofitting requires working with a little more attention to detail than your typical run and gun new install. But, when installed correctly, the benefits for the building owner can be game-changing. 

Read the transcript or Listen to the episode to learn more about roof retrofitting.