When your roof starts to wear down, you may wonder: Can I just add a new roof on top of the old one? This is called roofing over or overlay roofing, and while it might sound like a smart shortcut, it’s not always the best choice—especially if you're trying to avoid roof leaks.

What Is Roofing Over?

Roofing over means putting a new shingle roof over your current one without tearing the old one off. This is often called a nail-over reroof or the bridging method. It works only if the underlying structure is solid and your layers of shingles are still in good shape. But here’s the problem: if your current asphalt shingles are already curling or breaking, adding more on top can trap heat, cause trapped moisture, and eventually lead to serious leaks.

Why Roof Leak Prevention Matters

Leaks are more than just annoying. They can cause mold, fungal and bacterial growth, and damage to your walls, ceilings, and insulation. That's why roof leak prevention should always be your first concern. Adding more shingles over curled or damaged ones—like old 3-tab shingles or even architectural shingles—can cause problems instead of solving them.

Teamwork Exteriors—Leak prevention specialists in Bismarck—helps homeowners make the safest choice by doing a full roof inspection before recommending an overlay or full replacement.

Is Roofing Over Allowed?

It depends on building codes in your area. In many places, you can’t have more than two layers of shingles. Why? Because extra weight can be dangerous. It can put stress on your ceiling joists, ridge beam, ridge board, and even the deck of the roof. Before you go ahead with overlay roofing, you should always check local codes or ask a professional roofer.

What's Under Your Roof Matters

Your shingles aren’t the only thing that protect your home. Underneath, there’s roof decking, felt paper, roof flashing, and sometimes systems like Armourbase Pro Plus. These materials protect your roof from water, heat, and wind. But if the original layers are already damaged or trapping moisture, you’re just covering up a problem.

The truth? If your tile roof, bitumen shingles, or asphalt shingle roof is showing signs of curling or decay, tearing it off is a smarter long-term move.

The Risk of Voiding Warranties

Another thing to keep in mind: most manufacturer’s warranties don’t cover overlay roofing. That means if something goes wrong later—like storm damage or poor sealing around roof penetrations—you might be stuck with the bill. Brands like IKO Cambridge 53, Fortified Roofing, or even experts like Bill Ragan Roofing and Lyons Roofing usually recommend full replacement if the roof is aging.

How to Prevent Leaks in Your Roof

If you're wondering how to prevent leaks in your roof, here are simple steps you can take:

• Choose quality roof materials and proper roof covering

• Make sure your ridge and hip covering and metal flashing are properly installed

• Hire a professional roofing contractor who understands storm protection

• Avoid putting new shingles over curling shingles

• Always start with a complete building inspection

These are the best methods for preventing roof leaks in Bismarck, ND.

What About the Cost?

While roofing over may seem cheaper, it's not always the best deal. The cost to reroof a house may rise if problems hidden under the old shingles aren’t discovered in time. In some cases, skipping the removal process may lead to more expensive repairs later. That’s why working with a local expert like Teamwork Exteriors—Leak prevention specialists in Bismarck is key. They’ll give you roofing solutions tailored to your home and budget.

Ready to get a reliable, fair roof estimate from a team that Bismarck trusts? Contact Teamwork Exteriors today for expert guidance, trusted roof warranties, and a roofing partner that puts your home first. Call (701)-955-0676 or book your inspection now!