Chimney leaks are one of the most common roofing issues homeowners face. Water running down the roof often gets trapped behind the chimney, creating a perfect spot for leaks, mold, and rot. This is where a roof cricket becomes essential. A roof cricket works with your flashing system to move water around the chimney, instead of letting it pool behind it. But many homeowners still ask: when should a chimney be flashed with a cricket?

In this guide, you’ll learn exactly when a chimney needs both a cricket and flashing, why proper installation matters, what building codes say, and how professionals—including Local Chimney Sweep Services and trusted companies like AAA Air Duct Cleaning—make sure your chimney stays safe and dry

What Is a Roof Cricket and Why Is It Important?

A chimney cricket, also called a roof saddle, is a small triangular structure installed on the high side of a chimney. Its job is simple. It diverts water away from the back of the chimney so water doesn’t sit in one place. Without a cricket, rainwater and melting snow can pool behind the chimney, soak into shingles, damage the flashing, and seep into your attic or interior walls.

The cricket works hand-in-hand with the flashing. If the cricket redirects water, the flashing creates a waterproof seal. Together, they stop leaks

When Should a Chimney Be Flashed With a Cricket? (The Simple Answer)

A chimney should be flashed with a cricket when the chimney is 30 inches or wider, measured perpendicular to the roof slope. This guideline comes from most U.S. building codes.

Any chimney wider than 30 inches creates a “dead spot” behind it where water naturally collects. A cricket is required to prevent leaks and protect the flashing. Without a cricket, the flashing alone cannot handle the constant moisture.

But size isn’t the only factor. There are several other signs and situations where your chimney should have both flashing and a cricket

Situations When a Chimney Needs a Cricket and Flashing

1. When the Chimney Is 30 Inches Wide or More

This is the most important rule. If your chimney is 30 inches or wider, a cricket is not optional. It is required by building code for proper water drainage and to protect the flashing system.

2. When You Have a Steep Roof

Steep roofs (like 6/12, 8/12, and higher pitches) push water downhill faster. When that fast-moving water hits the back of the chimney, it forms a pool unless a cricket redirects it.

A cricket helps slow water down and move it to the sides.

3. When You Live in a Heavy Rainfall Area

Homes in rainy regions need better water management. Rain can quickly overwhelm flashing alone. A roof cricket keeps water moving around the chimney so moisture doesn’t sit at the base.

4. When You Get Snow Accumulation

Snow buildup behind a chimney is one of the biggest causes of leaks. When the snow melts, water flows straight into the flashing seams. Areas with snow need a chimney cricket even if the chimney is slightly under 30 inches.

5. When There Are Signs of Water Damage

Even if your chimney is smaller than 30 inches, these signs indicate you need a cricket:

• Interior leaks near the chimney

• Dark stains on ceiling or drywall

• Damp attic insulation

• Water marks on bricks

• Moldy smell near the chimney

• Rotting wood behind the chimney

• Curling shingles around the chimney

These signs mean water is not draining properly. A cricket helps fix the issue.

6. When Flashing Has Repeatedly Failed

If your chimney flashing has been repaired multiple times, the real problem may be drainage—not the flashing itself. A cricket helps protect the flashing so it lasts longer and stays sealed.

7. When Replacing or Upgrading Your Roof

If you’re getting a new roof and your chimney meets the width requirement, it’s the best time to add a cricket. Putting one in early prevents future leaks and protects your new shingles.

8. When You Have a Large or Tall Chimney

Bigger chimneys block more water and often create shadows where moisture stays longer. A cricket helps water escape and prevents long-term damage

Why Flashing and a Cricket Must Work Together

Many homeowners think flashing alone is enough. But flashing only seals the bottom and sides of the chimney. It cannot stop water from sitting behind it.

The cricket redirects water.

The flashing seals the edge.

They must work together to create a full waterproof system.

If one is missing, leaks are much more likely

What Happens If You Don’t Install a Cricket When Needed?

Skipping a cricket can lead to costly problems:

• Constant moisture around flashing

• Water leaking into the attic

• Mold and mildew growth

• Rotting roof decking

• Damaged shingles

• Interior wall damage

• Higher repair costs

• Repeated flashing failure

Water damage spreads fast. A cricket is a simple solution that prevents thousands of dollars in repairs

How Professionals Install Flashing With a Cricket

Here’s how roofing teams and Local Chimney Sweep Services build and flash a cricket:

1. Inspect the chimney and surrounding shingles

They look for leaks, rot, moisture, and flashing damage.

2. Build a custom-sized cricket

The height must match the roof pitch for proper drainage.

3. Install underlayment and ice shield

This provides a waterproof base.

4. Add step flashing and counter-flashing

Each piece interlocks with the shingles and chimney for a watertight seal.

5. Seal all seams

High-grade sealants protect against wind-driven rain.

6. Test water flow

Experts check how water moves around the chimney to ensure proper function.

Why Professional Installation Matters

A cricket and flashing setup must be precise. If the height is wrong, if flashing overlaps poorly, or if angles are misaligned, the chimney will leak. This is why expert installation is important.

Professional Local Chimney Sweep Services and roofing teams know:

• Correct roof pitch calculations

• Proper flashing layering

• How to handle wide chimneys

• How to waterproof the base

• How to prevent long-term leaks

This ensures your chimney is fully protected

How AAA Air Duct Cleaning Helps Homeowners

If you live in the DMV area, AAA Air Duct Cleaning offers chimney inspections that include checking your flashing, moisture patterns, and whether you need a roof cricket. Their team provides:

• Chimney cleaning

• Moisture and leak inspections

• Flashing repair

• Cricket assessment

• Chimney cap evaluation

• Waterproofing recommendations

Their experience helps homeowners avoid major water damage and costly repairs

Conclusion

A chimney should be flashed with a cricket whenever the chimney is 30 inches wide or more, or when roof pitch, rainfall, or snow conditions create water pooling behind the chimney. Flashing and crickets work together to protect your chimney from leaks, rot, and long-term water damage.

If you’re unsure whether your chimney needs a cricket, reach out to Local Chimney Sweep Services or trusted experts like AAA Air Duct Cleaning. Their teams can inspect your roof, evaluate your chimney size, and ensure your home stays dry and safe.