Roof Over Roof Installations: Is Reroofing a Good Idea?

When your roof starts showing its age or springs a leak, it’s decision time. You’ll likely be weighing your roofing options, wondering which one fits your needs best.

If patching up your roof won’t cut it anymore, but it’s not quite time for a full replacement, you should consider re-roofing. This means installing a new roof right over your existing one.

It’s a less drastic (and less expensive) option than a complete tear-off. But, there are key factors to consider. We’re here to help you make your next big decision: Roof over roof, or replacement.

How Do Contractors Install a New Roof Over Your Old One?

Going scorched earth and installing a new roof for your home is expensive. But costs shouldn’t be the only factor. If you want to install a roof over your old one, here’s what to expect:

Inspection and Preparation

The contractor begins with a thorough roof inspection, checking for any damage, leaks, or structural weaknesses. Then give you an estimate of the cost or how much roofing material you need. Any necessary repairs are completed before moving forward.

Cleaning, Debris Removal, and Underlayment Installation

Next, the roof is meticulously cleaned, removing debris, moss, or algae that could hinder the new shingles’ adhesion. Depending on the existing underlayment’s condition and local building codes, a fresh layer might be added for extra protection against leaks.

Shingle, Flashing, and Ridge Vent Installation

Then comes the installation of the new shingles, starting from the bottom and working upwards, ensuring proper overlap and alignment. Flashing around chimneys, vents, and other penetrations is replaced or installed to prevent leaks, and ridge vents might be added for better attic ventilation.

Important Considerations When Doing Roof Over Roof Installation

Reroofing isn’t always the answer. Local building codes might restrict the number of shingle layers, and your existing roof needs to be in good condition without major damage or sagging.

The added weight of new shingles is also a factor. Your roof structure must be able to handle it. While reroofing is generally quicker and more budget-friendly than getting your roof replaced, keep in mind that the final look might be slightly uneven due to the old shingles underneath.

When Should You Consider Doing a Roof Over Roof Installation

Before committing to doing a roof-over-roof installation, consider if it makes sense for your exact needs. Here are the benefits and some clear signs that reroofing is for you.

When Reroofing Makes Sense

Reroofing is a smart choice when your roof is showing signs of wear and tear but its underlying structure remains solid. Think of it like this: your shingles might be faded or losing granules due to age and weather, but they’re not leaking or curling. That’s the perfect scenario for adding a new layer of shingles over the existing ones.

The Benefits of Layering

Adding another layer of quality shingles acts like an extra shield for your roof. It teams up with the underlayment, roof deck, and original shingles to create a powerful barrier against leaks and damage. Consider it an upgrade, a rejuvenation. It also helps channel water into your gutters and downspouts, preventing pooling and potential problems.

More Than Just Protection

Reroofing is an opportunity for a fresh look. Maybe you want a new color or style, or you’re renovating your entire home and want the roof to match. Even if aesthetics aren’t your primary goal, a new shingle layer adds depth and a subtle three-dimensional appearance, enhancing your home’s curb appeal.

The Financial Advantage

Reroofing is a budget-friendly alternative to a complete roof replacement. Since there’s no need to tear off the old roof, you save on labor, disposal fees, and time. Your roofer can get straight to work installing the new layer, making the whole process faster and more cost-effective.

Signs You SHOULDN’T Do a Reroofing Project

The prospect of saving some serious cash with a reroofing project is enticing. However, there are clear signs of when reroofing won’t be the best choice for your home such as:

When Your Roofing Contractor Tells You It’s a Bad Idea

Trust the pros. When they tell you it’s not going to work out—chances are, it’s not. Any reputable contractor will be upfront about whether your roof can handle reroofing.

That’s the whole point of a thorough inspection—to assess your roof’s condition and recommend the best course of action. It’s always wise to get estimates from a few different contractors to ensure you’re making the right choice and finding the perfect fit for your needs.

Your Roof Isn’t Made From Asphalt Shingles

One clear-cut reason why reroofing might not be possible is if your roof isn’t made of asphalt shingles. Layering only works with shingles on shingles; you can’t mix roofing materials or install a new layer over slate or wood tiles.

If Shingles are Curling

Curling shingles are another red flag. A new layer can only be installed on a flat and level surface. If your shingles are curling due to age or weather, you’ll need to address that issue first, possibly by replacing the damaged shingles, before considering reroofing.

When There Are Already Two Shingle Layers

Reroof your house once, save some cash. Do it twice, save some more. Three times? That’s generally not a good idea. Stacking shingles on top of each other adds a lot of weight.

The extra weight could put too much strain on your roof structure. And finally, if your roof has extensive visible damage, covering it up with another layer isn’t the solution. A complete tear-off is necessary to fix the underlying problems and ensure a safe, long-lasting roof.

Why You Shouldn’t DIY Roof Over Roof Installations

If you’re thinking about things you can DIY roof repair—roof replacements probably aren’t one of them. It’s doable for people with experience and the right tools. But, reroofing isn’t something you can learn after watching a few videos on YouTube.

Reroofing Made Simple

Reroofing is a smart choice when your roof is nearing retirement but still in decent shape. It’s perfect if your shingles are showing their age but the underlying structure is sound.

But before committing to a roof-over-roof installation, make sure to have your roof inspected by professionals. That’s where Trenton Roofing comes in. Get a free quote today!