There's no way around it, sometimes a roof just needs to be replaced. Too much time has gone by and there's too much damage or too much deterioration to the roof and there remains no reasonable way to restore what's there.
Since this scenario tends to be the most costly of the roofing options, it is imperative that you understand your options and avoid wasting money on a product or installation method that will ultimately fail.
But what do we mean when we say “replacement?” To fully understand what replacement means, it’s probably best to compare and contrast the terminology as it relates to the various ways a roofing need can be addressed.
The 3 Basic Roofing Scenarios
- A roof replacement generally describes the process of removing one or more existing roofing systems before installing a new roofing system in its/their place.
- A roof recovery generally describes the process of leaving an existing roofing system in-place and installing a new roofing system on top of it. The term “recovery” is often used interchangeably with the term “overlay.”
- A roof restoration generally describes the process of restoring a roof to a like-new condition by enhancing it appearance, "watertightneess," and performance against the elements, and is usually accomplished by the installation of a fluid-applied membrane or elastomeric coating.
- Instead of being a 4th roofing scenario, the term reroof is a catchall term that typically refers to either (1) roof replacement or (2) recovery/overlay. So a reroofing project could be a replacement scenario in which some form of tear-off is required or it could be a recovery scenario in which the exiting roofing system remains in-place and a new roofing system is installed on top of it.
Is a Tear-Off Required?
Whenever a tear-off is required, as in the case of a roof replacement, the costs are usually much higher than other methods. In addition to the increased costs, tear-offs are usually noisy, messy, disruptive, and add a lot of roofing debris to the landfill.
If a roof is addressed before it deteriorates beyond the point of no return, a roof restoration is often the best option. But when restoration is not an option, you’ll be left with either a replacement or a recovery scenario. Which one is best? Well that depends.
Building codes for most jurisdictions around the country do not allow for more than 2 roofing systems to be in-place. So that means if your roof already has 2 roofing systems installed – like the original roof and then a second roof install 15-years later – then both roofs will need to be torn off down to the roof substrate before the new roof and be installed.
If you only have one roof installed, a recovery (a.k.a. “overlay”) could be done. Core cuts are usually done to determine how many roofing systems are installed and such information is a requirement of the permitting process.
The requirement of a tear off carries with it 2 main benefits: First of all, it helps to prevent unnecessary weight from being added to the roof, which protects the integrity of the structure’s load-bearing properties. Secondly, it allows for a good look at the substrate so that any damage that is found can be repaired. Your new roofing system is no good to you if your roof structure caves in due to too much weight or because the substrate rusted through (metal) or rotted out (wood).
Sometimes when you're in a situation where you only have one roof installed, the cost to do an overlay versus that of a restoration might actually be comparable in cost. In fact, a high-quality roof restoration system may be a little bit more expensive than an overlay.
A Final Thought
With all the options and possible scenarios that may be unique to your roof, it is critical to work with a contractor that understands the importance of such concepts as roof substrates, structural integrity, code compliance, in addition to the various installation types and methods.