Why Proper Cricket Flashing Roof Install Matters for Your Home
Cricket flashing roof install is a specialized roofing technique that protects your home from water damage around chimneys and large roof penetrations. Here’s what you need to know:
Quick Answer: Essential Cricket Flashing Installation Steps
- Assessment – Determine if your chimney needs a cricket (typically required for chimneys wider than 30 inches on the upslope side)
- Frame Construction – Build a peaked structure using 2×4 or 2×6 lumber to match your roof’s pitch
- Sheathing – Cover the frame with plywood and waterproof underlayment
- Flashing Installation – Apply metal flashing (copper, aluminum, or galvanized steel) with proper overlaps
- Sealing – Secure all joints with counterflashing, lead wedges, and polyurethane sealant
- Integration – Weave shingles and valley flashing to match your existing roof
When you spot a leak around your chimney, there’s often a simple explanation. As one professional roofer discovered when investigating a persistent leak: “Measuring nearly 7 feet wide, the chimney sat like a dam at the bottom of a steep roof, with no cricket to divert water around the sides.”
Without a properly installed cricket, water pools behind your chimney instead of flowing off your roof. This pooling leads to rot in your roof deck, damaged masonry, and costly interior water damage—especially problematic in St. Louis where we experience heavy rain and snow loads.
The International Residential Code requires crickets for chimneys wider than 30 inches, but the National Roofing Contractors Association recommends them for any chimney over 24 inches wide or on roofs with slopes of 6:12 or steeper. Even smaller chimneys benefit from this protection.
What is a Roof Cricket and Why is it Essential?
To the uninitiated, the term “cricket” might bring to mind a chirping insect or perhaps a long-winded British sport. However, in roofing, a cricket (also known as a chimney saddle) is a vital structural component designed to save your home from the slow, destructive power of water.
By definition, a roof cricket is a double-sloped, triangular structure built onto the high side of a chimney or any other roof projection that sits perpendicular to the slope. Its primary job is to act as a diverter. Instead of allowing rainwater to slam into the back of your chimney and sit there like a pond, the cricket splits the flow and sends it safely around the sides.
According to Dictionary.com, the origin of the term “roof cricket” remains a bit of a mystery. Some suggest it comes from the word’s archaic meaning as a “low stool,” implying it’s a small seat for the roof. Others have joked that roofers used to sit on them during breaks, though we certainly don’t recommend that! And no, despite the popular myth, Disney’s Jiminy Cricket wasn’t named after a chimney cricket—though he was a “minced oath” for a different historical figure.
Whatever the name’s origin, the function is clear. Without a cricket, the area behind a wide chimney becomes a “dead zone” where leaves, snow, and debris accumulate. This damp pile traps moisture against the shingles and masonry, leading to:
- Wood Rot: Moisture seeps into the roof deck and rafters.
- Masonry Erosion: Constant water contact causes mortar joints to fail.
- Mold Growth: Damp conditions inside the attic space.
Ensuring you have a proper cricket flashing roof install is one of the best ways to extend the Understanding the Lifespan of Your Home’s Roofing. In our experience serving homeowners in St. Louis and Chesterfield, a well-built cricket can be the difference between a roof that lasts 30 years and one that needs a major overhaul after ten.
When is a Cricket Flashing Roof Install Required?
We often get asked, “Do I really need one?” While we believe most chimneys benefit from a diverter, building codes and industry standards provide specific mandates.
The 2015 International Residential Code (IRC) is the gold standard here. It explicitly states that a roof cricket is required for any chimney that is 30 inches or wider (measured parallel to the ridge) if it is located on the upslope side of a roof. You can find these guidelines in the 2015 International Residential Code for chimneys.
However, many professional organizations, like the National Roofing Contractors Association (NRCA), suggest even stricter standards. They recommend crickets for:
- Chimneys more than 24 inches wide.
- Any roof with a slope of 6:12 (27 degrees) or greater.
- Areas with high snow or debris accumulation (which definitely includes our service areas like O’Fallon and St. Peters).
If your roof is particularly steep, the height of the cricket must increase to ensure water doesn’t “overtop” the peak of the diverter. Using the wrong dimensions is one of the most Martin & Sons LLC’s Guide to Common Roofing Problems we see during inspections.
Cricket Height Requirements by Roof Pitch
| Main Roof Pitch | Cricket Height (as a fraction of chimney width) | Example: 36″ Wide Chimney |
|---|---|---|
| 12:12 | 1/2 the width | 18″ high |
| 8:12 | 1/3 the width | 12″ high |
| 6:12 | 1/4 the width | 9″ high |
| 4:12 | 1/6 the width | 6″ high |
| 3:12 | 1/8 the width | 4.5″ high |
Determining the Correct Slope for a Cricket Flashing Roof Install
The goal of a cricket is efficient drainage. To achieve this, the minimum recommended slope for a roof cricket is 1/4 inch per foot. However, in practice, we usually aim to match the pitch of the main roof. This not only looks better but also makes the framing math much simpler.
If you live in a part of St. Louis prone to heavy snow, like Florissant or Creve Coeur, a steeper slope is often better. A steep pitch ensures that heavy slush and ice don’t sit on the cricket, which can lead to “ice damming” at the very spot you’re trying to protect.
Step-by-Step Guide to Building a Watertight Cricket
Building a cricket is a blend of carpentry and specialized roofing. While it might look like a simple “mini-roof,” the details in the flashing are what actually keep the water out. If you’re tackling this as a DIY project, make sure you Buy Fall Protection at Amazon before stepping onto the deck.
Here is how we handle Residential Roofing: How We Can Help during a cricket installation:
1. Framing the Structure
We typically use 2×4 or 2×6 pressure-treated lumber for the frame. To make life easier, we often build the frame on the ground.
- The Gable End: This is the vertical triangle that sits against the chimney.
- The Ridge: A double-beveled board that runs from the peak of the gable back to the roof deck.
- Sleepers: These boards sit flat on the roof deck and provide the “footprint” of the cricket.
Pro Tip: For metal crickets wider than 18 inches, the NRCA recommends wood framing be installed at the underside for support. This prevents the metal from “oil canning” or sagging under the weight of snow.
2. Sheathing and Underlayment
Once the frame is secured to the roof deck (using structural screws, not just nails), we cover it with 1/2-inch or 5/8-inch plywood. The most critical step follows: Ice and Water Protector. We wrap the entire cricket and extend the underlayment at least 12 inches up the chimney and 12 inches onto the main roof deck. This creates a secondary waterproof barrier.
3. Choosing Your Materials
The “best” material often depends on your budget and the look of your home:
- Copper: The gold standard. It’s beautiful, lasts a lifetime, and can be soldered for a perfectly watertight seal.
- Aluminum: A great, cost-effective option that doesn’t rust.
- Galvanized Steel: Strong and traditional, though it requires proper coating to prevent corrosion over time.
Preparing the Deck for a Cricket Flashing Roof Install
Before the new wood goes down, you have to “start fresh.” You cannot simply build a cricket on top of old shingles. This is a common mistake that leads to trapped moisture and rot.
When calculating Roof Installation Costs: Key Factors That Affect Pricing, labor for “tear-off” is a factor.
- Shingle Removal: Strip the shingles at least 2 feet away from the chimney on all sides.
- Sheathing Inspection: Check for soft spots. If the wood is punky or black, replace it now.
- Debris Clearing: Remove old nails and dried-out caulk.
- Layout Marking: Use a chalk line to mark the center of the chimney and the “wings” of the cricket.
Critical Flashing Techniques for a Watertight Seal
This is where the magic happens. A cricket flashing roof install is only as good as its edges.
- Reglet Cutting: Instead of just gooping sealant on the brick, we use an angle grinder to cut a “reglet” (a thin groove) into the mortar joints. The top edge of our metal flashing is tucked into this groove.
- Lead Wedges: To keep the flashing in the reglet, we drive small lead wedges into the gap. This provides a mechanical hold that won’t pull out as the house shifts.
- Apron Flashing: This is the piece that sits at the very bottom of the chimney. We use double bends to ensure water is kicked away from the corner.
- Step Flashing: Along the sides of the cricket, we install L-shaped metal pieces between every single course of shingles.
- Counterflashing: This is the “shield” that covers the top of the step flashing. It’s what gets tucked into the reglets we cut earlier.
- The Solder vs. Sealant Debate: In critical corners, we prefer soldering copper. If using aluminum or steel, a high-quality polyurethane sealant is essential. Avoid cheap silicone; it doesn’t bond well to masonry over the long term.
Frequently Asked Questions about Roof Crickets
How much does it cost to install a roof cricket?
The cost of the cricket structure itself is typically at least $100 to $200 in materials. However, the labor for a cricket flashing roof install is where the price varies.
- A basic aluminum retrofit might cost between $500 and $1,500 depending on the roof pitch.
- A custom copper cricket with soldered joints on a large chimney can exceed $2,500.
In the St. Louis market, factors like the height of the chimney and the type of roofing material (slate vs. asphalt) will influence the final quote.
Can I install a roof cricket on an existing roof?
Yes! This is called a retrofit. While it’s easiest to do during a full roof replacement, we often perform standalone cricket installs for homeowners in Maryland Heights or O’Fallon who have persistent chimney leaks. The process involves carefully removing the surrounding shingles, building the frame, and then “weaving” the new shingles back into the existing field.
Do all chimneys need a cricket?
Technically, no. If your chimney is narrow (under 24-30 inches) or if it sits right at the very peak (the ridge) of your roof, a cricket isn’t necessary because there is no “upslope” water to divert. However, if your chimney is on a slope and is wider than two feet, we almost always recommend one as preventative maintenance. It’s a small investment that prevents a $10,000 masonry repair bill later.
Conclusion
A cricket flashing roof install might seem like a small detail, but it is one of the most important components of a high-performance roofing system. By diverting water away from vulnerable intersections, you protect your home’s structural integrity and avoid the headaches of chronic leaks.
While a handy homeowner might be able to frame a basic cricket, the technical nature of masonry reglets, lead wedges, and watertight flashing is best left to the pros. At Martin & Sons, we’ve spent years perfecting the art of the watertight chimney.
Whether you’re in St. Louis, St. Charles, or Maryland Heights, we offer:
- No upfront deposits: You only pay when you are 100% satisfied.
- Lifetime labor warranties: We stand by every piece of flashing we install.
- Expertise: We know how to handle the unique weather challenges of the Gateway City.
Don’t wait for the next heavy St. Louis downpour to find out your chimney is acting like a dam. Top Benefits of Professional Roofing Services include peace of mind and long-term savings.
Ready to protect your home? Schedule your roofing maintenance today and let us ensure your chimney is ready for whatever Mother Nature throws its way.