Reshingling Over Your Existing Roof

Is Reshingling Over Your Existing Roof a Good Idea?

Leaks and other issues may crop up as your roof nears the end of its lifespan. So, when it comes time to make roofing decisions, many Colorado homeowners wonder, “Is reshingling over your existing roof a good idea?” While some municipalities may allow two layers of shingles, the majority do not and most reputable roofing companies, including Just Roofs and Gutters, will not shingle over existing material.  For example, the Colorado Springs Roofing Codes state that roofers must remove existing layers before they can install new shingles. So, let’s break down why it’s not such a good idea to add more than one layer to your roof. 

Overlaying vs. Replacement

Overlay, also called reroofing, is when a new layer of shingles gets installed on top of the existing roof. Extra material on the roof means excess weight, which can strain the rafters. Some think overlaying is better because it’s less labor-intensive and thus more cost-effective. However, the extra weight is not good for your structure. In contrast, replacement involves tearing off the existing roof cover and installing new shingles. This is indeed much more labor intensive, but there are benefits to tearing down the deck and replacing the covering. 

Is reshingling over your existing roof a good idea?

Some cities, like Denver, require roofs to be removed and replaced after two layers of roof covering. So, homeowners might think it’s a good idea to add a second layer if the underlying support is still sound. However, shingles are heavy, and your roof decking may not be strong enough to support a second layer. It is also important to note that shingles nailed into multiple layers and not directly to the deck don’t hold nearly as well – which can result in ‘blow-offs’ in high winds.  A roofing professional can check your structure and recommend the best course of action and advise whether you’re within your manufacturer’s warranty since many manufacturers will void their material warranties if their installation instructions are not followed and all of them insist on a smooth nail-able surface.  

When is reshingling a bad idea?

Over time, roofs wear out due to weather and age. After about 20 or 30 years, shingles lose their granules and become bald. Some people opt to add an overlay if they live in a place that allows that. However, they definitely need to be torn down and replaced the next time. Two layers are heavy enough. Likewise, laying over curling or bulging shingles is a bad idea. Roofers need a level surface for reshingling, or you risk water leaking underneath. An experienced roofer can inspect and provide a roof health report that gives you valuable information on your roof needs. 

Is it cheaper to roof over existing shingles?

Roofing over existing shingles may be a budget-friendly option in the short term. On average, overlay jobs are less expensive than complete shingle replacement due to reduced labor costs. However, new roofs tend to have better durability and a longer life span. That extra durability protects your roof against Colorado hail storms and may cost less in the long run.

Get Expert Advice

Reroofing isn’t an option for most homes in Colorado due to municipal regulations. So when you’re asking, “Is reshingling over your existing roof a good idea,” get advice from a roofing professional who knows the codes. The Just Roofs and Gutters experts can inspect your roof and provide advice on taking care of your roof. Give us a call at 719-374-8304.

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