Connecting a Flat Roof to a Shingled Roof

You may have a home with a sloped roof or a flat roof. If you need a new roofing system, it can get complicated. Shingles will not work on a flat roof. How should a flat roof and shingle roof be tied together? Take a look at the photos above from start to finish using CertainTeed shingles and find out more.

How to Tie a Flat Roof Into a Shingle Roof

Many Florida homes include a combination of sloped and flat roof section, especially over porches, additions, or garages. If you’re planning a roof replacement, you might be wondering: How do you properly tie a flat roof to a shingle roof? The answer is critical to keeping your home watertight and preventing leaks.

Why Shingles Don’t Work on Flat Roofs

Shingles are designed for pitched roofs where water can easily drain away. They overlap like scales on a fish, allowing rainwater to run off quickly. On a flat or low-sloped roof, however, water doesn’t drain as fast. If shingles are used, water can pool and seep underneath the layers, causing leaks, rot, and even structural damage. That’s why shingles should never be installed on a flat roof; instead a proper transition system must be used where the two roof types meet.

How to Tie a Flat Roof to Shingles the Right Way

The key to a waterproof connection is using a roofing membrane (such as modified bitumen or TPO) that extends up under the shingles. This creates a continuous barrier that channels water away from the seam and toward the roof’s edge or gutters.

At Triangle Roofing Inc., our experienced roofers install the flat roof membrane so it runs several inches up beneath the shingled section. Then the roofing shingles are layered over it to ensure proper drainage and a smooth transition. This prevents ponding water. The result? A clean, professional finish that looks seamless and performs well through Florida’s storms, humidity, and heat.

Get a Professional Roof Inspection

If your home has both flat and sloped roofing, it’s important to have a really good roofer evaluate how they tie together. Small mistakes in this area can lead to major leaks later.

Joseph, Sr. or Joe, Jr. at Triangle Roofing will come out and look at the type of roof you have so that you can install the best roofing for your home. It is hard to assess roof damage from the ground: you need a roofing expert to walk on your roof and use a trained eye to spot any problem areas. Do NOT get up on the roof yourself!

A new roof is a big investment and you need it done right! Give Joe at Triangle Roofing a call today at 386-673-6600 or send an email to: joe.delia@triangleroofingusa.com.