Chimney Cricket Installation – Redirecting Water Away from Your KC Roof
Shadow is the word I’d use to describe the real problem spot on most Kansas City roofs-that uphill side of your chimney where water stacks up out of sight, not the bricks you can see from the driveway. A chimney cricket is just a small peaked bump built on that uphill face to split the flow and send it around both sides of the chimney before it ever gets the chance to creep under your shingles and into your ceilings.
Why So Many “Chimney Leaks” in Kansas City Start Above the Brick
On more than half the “chimney leak” calls I run in Kansas City, the first thing I look for is the size of the chimney and whether there’s a cricket at all. Most of what I see labeled as a chimney leak is actually a roof design problem-water piling up in the shadow behind a wide chimney because there’s nowhere for it to go except sideways under the flashing. The masonry itself is fine. The mortar is fine. The problem is that nobody built a path for the water. A correctly framed and flashed cricket could have prevented years of ceiling staining and rotted decking on dozens of roofs I’ve been called out to fix.
One August afternoon, dead heat and no breeze, I was on a Mission Hills roof where the homeowner was absolutely convinced his skylight was leaking. I followed the water trail under the shingles and it started all the way over on the uphill side of his massive brick chimney-no cricket, just a flat wall catching every drop of every storm. The rain had been bouncing off that chimney face for years, sneaking under the flashing, and traveling a full ten feet across the decking before it finally surfaced at the skylight. We framed and flashed a proper cricket, and the “skylight leak” never came back, because it was never a skylight problem in the first place. And honestly, that’s not even an unusual story around here. If your chimney is wider than 30 inches and you’re in KC without a cricket, you’re gambling with every thunderstorm that rolls up from the south.
Early Signs Your Leak Is a Roof Design Issue – Not Just Bad Caulk
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✅ Stain appears 3-10 feet uphill or to the side of the chimney
Water traveled under shingles before surfacing – the chimney face is deflecting it laterally, not soaking it in. -
✅ Dampness is worse after long, steady rains than quick showers
A pooling problem behind the chimney fills slowly – it needs sustained rain to saturate and push through, not a ten-minute pop-up storm. -
✅ Slight dip or sag in shingles just behind the chimney
Visible from the yard on a bright day – that low spot is decking that’s been holding water for seasons. It’s a structural flag, not just cosmetic. -
✅ Previous “repairs” were caulk beads or tar smeared at the brick line
Sealant doesn’t redirect water – it just covers the evidence temporarily. The design problem behind the chimney is still wide open. -
✅ Ice dams or snow melt ridges form only at the uphill side of the chimney in winter
Water is pooling behind the chimney, then freezing in place – exactly the pattern you’d expect with no cricket to move it along.
What a Chimney Cricket Actually Is-and When KC Codes Expect One
Think of Your Chimney as a Rock in a Shallow Creek
Imagine putting a big rock in the middle of a shallow creek – that’s exactly what your chimney is to your roof, and the cricket is the little channel you carve so the water doesn’t eat away at the banks. A cricket is a small, peaked mini-roof framed on the uphill side of your chimney. It has two sloped faces that split and redirect runoff around both sides of the chimney rather than letting it pile up against the brick. Now follow that water in your mind: it comes down the main slope, hits the cricket’s ridge, divides left and right, and slides around the chimney corners through metal valley flashing. The decking behind the chimney stays dry. The shingles stay sealed. That’s the whole job – and it’s elegant in how simple the physics are once you see it.
Follow the Water: Size, Slope, and When a Cricket Becomes Mandatory
Here’s my honest opinion: if your chimney is wider than 30 inches and you’re in KC without a cricket, you’re gambling with every thunderstorm that rolls up from the south. That 30-inch number isn’t arbitrary – in most Kansas City jurisdictions and in manufacturer specs for major shingle lines, chimneys with an uphill face wider than 30 inches on a sloped roof are expected to have a cricket. Steeper roof pitches and taller chimneys gather even more water volume, so the threshold for “strongly recommended” starts a bit earlier, around 24 inches, especially on windward sides that catch our southerly storms.
I’ll never forget a January call in Blue Springs, 6:30 in the morning, windchill at two degrees. A townhouse owner had ice literally growing out of the ceiling paint near the fireplace. The builder had skipped the cricket on a wide chimney sitting on a low-slope addition, and every light snow KC got that winter was pooling and refreezing right behind the chimney. I had to chip through two inches of ice to even see the rotten decking underneath. We framed the cricket, re-decked the whole section, and the next snow just slid around the chimney the way it was supposed to. Here in KC, it’s not always the big February blizzard that does the damage – it’s those repeated light snows with hard overnight freezes and then a 45-degree afternoon melt. That freeze-thaw cycle, with wind pushing moisture from the south or southwest, turns a skipped cricket into a slow demolition project on your decking and rafters.
| Uphill Chimney Width | Roof Slope (approx.) | Cricket Recommendation in KC |
|---|---|---|
| Under 24″ wide | 6:12 or steeper | Cricket usually optional – proper step flashing and counterflashing are typically sufficient on steeper pitches that shed water quickly. |
| 24″-30″ wide | 4:12 – 8:12 | Cricket strongly recommended – especially on windward (south/southwest) sides that catch the bulk of KC’s heavy thunderstorm rain bands. |
| Over 30″ wide | Any sloped roof | Cricket typically required by code and manufacturer specs – no amount of sealant makes up for proper framing and runoff design at this width. |
| Wide chimney (any width >24″) | Low slope 2:12 – 4:12 | Cricket critical – water moves slowly on low-slope roofs, giving it far more time to pool behind the chimney. KC snowmelt and sustained spring rains make this a near-certain leak scenario without one. |
Don’t follow the stain – follow the water.
| Myth | Fact |
|---|---|
| “Crickets are only for fancy custom homes.” | A cricket is a standard roofing fix wherever a chimney is wide enough to block water flow – 1960s ranch, brick colonial, or new build. It doesn’t care what the house costs. |
| “Ice and water shield plus extra caulk means I don’t need a cricket.” | Membranes and sealants are your backup system – they’re not a substitute for actually routing water away from the chimney in the first place. One caulk failure and you’re back to a wet ceiling. |
| “My roof is new, so any leak must be the chimney masonry.” | A brand-new roof installed without the required cricket still funnels water behind the chimney on every rain. New shingles don’t fix a roof design problem. |
| “Crickets are just big blobs of tar and flashing.” | A real cricket is framed with lumber, sheathed with decking, covered in underlayment, and flashed with step flashing and counterflashing along defined valleys. It’s a small roof – built and detailed like one. |
How a Proper KC Chimney Cricket Is Designed, Framed, and Flashed
From Decking to Shingles: Follow the Water One More Step
Truth is, water doesn’t care how new your shingles are – if it hits a brick wall in its path, it’s going to find the easiest way underneath something. That’s my starting point every time I’m designing a cricket. I look at the chimney, figure out which direction the predominant water flow is coming from, then snap layout lines from both uphill chimney corners to establish the cricket’s ridge height and valley lines. The ridge has to be tall enough that both cricket faces shed water outward – not just barely tilted, but decisively sloped. From there it’s framing with proper dimensional lumber tied into the existing roof structure, sheathing with OSB or plywood, then underlayment lapped into the existing felt or synthetic on the main roof. Step flashing goes in along the cricket-to-chimney joints; counterflashing gets cut into the mortar joints or brick. In KC’s big downpours – and we get them, two inches in an hour is not rare here – even a small mis-angle or a low spot in the valley collects a lot of water fast. Every detail matters because the volume we’re dealing with is real.
What Goes Wrong With DIY “Crickets” After the First Big Storm
There was a job in Waldo where a DIY-minded engineer had built his own “cricket” out of leftover 2x4s and some bent aluminum flashing. He was proud of it – I could tell. First big spring storm, the water didn’t shed around the chimney. It funneled straight into the brick face because his little pyramid was pitched the wrong way – toward the chimney instead of away from it. By the time I got there on a gray Saturday morning, there was efflorescence blooming all over the chimney face and the interior plaster was bubbling from the moisture soaking through the masonry. We tore out the whole contraption, reframed a code-compliant cricket with proper ridge height and outward-facing slopes, and I walked him through the math right there on his kitchen counter with a salt shaker and a coffee mug as props. Here’s the insider tip I gave him, and I’ll give it to you too: a cricket that looks steep from the yard but is actually pitched toward the chimney is worse than no cricket at all. It takes water that would’ve spread across several feet of shingles and concentrates it into one narrow collision point against the brick.
Luis’s Chimney Cricket Installation Process in Kansas City
Verify decking condition behind the chimney, locate existing leak paths and rot, and map the water trail from uphill face to where it surfaces inside.
These three numbers determine cricket ridge height, slope angle, and which cricket face needs the most robust flashing.
Ridge and valley lines are snapped from the chimney corners up-slope. Framing lumber is sized and tied into existing rafters or trusses – not just toenailed into decking.
Plywood or OSB sheathing goes over the framing, then underlayment is lapped into the existing roof underlayment so there’s no exposed seam line.
Step flashing runs up each cricket-to-chimney joint course by course. Counterflashing is cut into the mortar or reglet and sealed. Metal valley flashing carries water off the cricket edges cleanly.
Shingles go on the cricket faces matching the main roof. Then I run a hose at the uphill face and watch where water actually goes – not where the plan says it should go.
⚠️ Dangers of Makeshift or Undersized Crickets
I see the same DIY errors come through on service calls, and most of them cause more damage than having no cricket at all:
- Framing not tied into rafters or trusses – a cricket nailed only into decking will shift under snow load or wind and open up flashing joints.
- Aluminum flashing nailed to the brick face instead of set into cut mortar joints – the face-nailed version separates after one hard freeze, leaving a gap water runs straight through.
- Cricket too narrow at the ridge – if the ridge doesn’t extend the full chimney width, water slams into the corners and finds the flashing joint at exactly the worst angle.
- “Tar pyramids” – roofing cement built up behind the chimney cracks after one freeze-thaw cycle and ends up holding water in the cracks rather than shedding it.
- Slope pitched toward the chimney – the single most damaging error. It concentrates all roof runoff into the brick face instead of diverting it, accelerating masonry deterioration and interior moisture damage.
What Chimney Cricket Installation Costs in the Kansas City Area
What you’ll pay depends on chimney width, how steep and tall the roof is, how easy it is to access that section of the roof, and how much damage is already waiting behind the chimney – rotten decking, compromised rafters, or failed original flashing that needs a full tearout. A one-story ranch with a modest pitch and minimal rot is a very different project than a 2.5-story Mission Hills home with a massive fireplace on a steeply pitched main roof. What I tell every homeowner is this: building a cricket correctly one time is almost always cheaper than two or three rounds of interior ceiling repair, insulation replacement, and mold remediation after several KC winters of ongoing leaks.
| Scenario | Scope of Work | Typical KC Cost Range |
|---|---|---|
| One-story ranch, moderate pitch, chimney just over 30″ wide, minimal decking damage | Frame new cricket, sheath, underlayment, step flash and counterflash, shingle to match existing roof | $900 – $1,800 Easy access and solid decking keep costs down |
| Two-story home, steep roof, existing minor leak staining but solid decking | Same framing and flashing work plus scaffold or staging on taller home; interior stain treated | $1,800 – $3,200 Height and pitch are the main cost drivers |
| Wide chimney on low-slope addition with rotten decking and damaged original flashing | Tear out damaged decking, re-deck, full cricket framing and flashing, tie into main roof system | $3,500 – $5,500+ Structural repair added to cricket build |
| Cricket added during a full roof replacement vs. retrofit as standalone project | Bundled during reroof: minimal added labor. Standalone retrofit: full mobilization cost, careful shingle matching required | +$600-$1,200 at reroof vs. $900-$2,500+ standalone Doing it at reroof time saves real money |
| “Do nothing” scenario with repeated leaks over 2-3 winters | Ceiling drywall replacement, insulation swap, potential mold remediation, re-painting, structural assessment | $4,000 – $12,000+ And the cricket still needs to get built at the end of it |
Questions to Ask Before Anyone Touches Your Chimney or Cricket
Treat this like a water-path investigation, not a shingle repair. Any contractor you talk to should be able to explain – in plain language, not trade jargon – where the water starts, what path it’s taking right now, and exactly how the cricket and flashing system will change that path. If they can’t walk you through it step by step, or if their answer is “I’ll just reflash it and seal it up,” that’s worth slowing down for.
Homeowner Checklist: Questions to Ask Any Cricket Contractor
- Can you explain whether my leak is from masonry, flashing, or the roof design behind the chimney? You want a clear answer, not a shrug and a tube of caulk.
- Will you show me photos of the uphill side of my chimney – any ponding areas, dips in the decking, or rot before work begins?
- Are you proposing a real framed cricket (ridge, valleys, sheathing, underlayment) or just adding metal flashing and sealant to the existing surface?
- How will the new cricket tie into existing roof underlayment and step flashing? This is where leaks live if it’s done sloppy – the seam between old and new.
- What chimney width and roof pitch are you basing the cricket size on? If they can’t answer that on the spot, they haven’t measured yet.
- Will you water-test the area after installation to confirm the runoff path has actually changed? Don’t skip this question.
Common Chimney Cricket Questions from KC Homeowners
Once you understand where water wants to go on your roof, a properly built cricket is almost always the cleanest and longest-lasting fix – and the one repair you won’t be redoing in three years. Give ChimneyKS a call and Luis will get up on your roof, trace the exact water path on a notepad, and design a cricket and flashing setup built for your specific Kansas City home, your roof pitch, and your budget.