A field guide to every residential roof form we work on in the Kansas City metro, what the pitch means for your material choice, and how to name the part that is giving you trouble.
Two houses on the same street with the same square footage can be completely different roofs. What separates them is shape and pitch: how many planes the roof has, how those planes meet, and how steeply they run. Those two things decide what materials are allowed, how long the job takes, where it will leak first, and what it costs.
This page is the reference we wish more homeowners had before calling for a quote. Start with the anatomy, because being able to name the part that is wet turns a confusing phone call into a dispatch.
Know what you are looking at
1Ridge and ridge ventThe horizontal peak. The vent hides under the cap shingles and is the exhaust half of your attic ventilation. Cap shingles blow off here first, because the ridge takes the most wind uplift.
2ValleyThe internal angle where two roof planes drain toward each other. It carries more water per foot than anywhere else on the roof, which is why it is one of the most common places a leak starts.
3Chimney flashing and cricketA chimney wider than 30 inches across the slope needs a cricket, a small peaked saddle on the uphill side, so water splits around it instead of ponding. Tar smeared on brick is a repair that fails.
4Roof-to-wall step flashingWhere a roof plane runs up alongside a wall, water is held back by many small interwoven L-shaped pieces, one per shingle course. Never a single strip and never caulk.
5Pipe bootThe rubber collar sealing each plumbing vent. The collar dries out and cracks in about 10 to 15 years, well before the shingles do, which makes this the most common small leak on a roof and usually a repair rather than a replacement.
6Eave and gutterThe level lower edge, where water leaves the roof. This is the ice dam zone in a Kansas winter. Water pouring off the front of the house in a storm is usually a clogged gutter, not a roof leak.
7RakeThe sloped edge running up the gable end. Easy to confuse with the eave, so remember it this way: the eave is level, the rake is sloped. They fail differently and are flashed differently.
8Soffit and fasciaThe underside of the overhang and the board the gutter hangs on. The soffit is also the intake half of your ventilation, and attic insulation blocking it from the inside is common and invisible from the ground.
Most leaks start where the roof meets something else, a wall, a chimney, a pipe or another roof plane, rather than out in the open field of shingles. Seven of the eight callouts above are one of those transitions.
Slope decides your options
Pitch is written as rise over twelve inches of run. A 6:12 roof climbs six inches for every foot it travels horizontally. It is not a style choice, it is a constraint: below a certain slope, shingles are not permitted at all.
The part almost nobody accounts for
A valley is always shallower than the two roof planes that create it. The NRCA puts a number on it: where two 4:12 planes meet, the valley itself runs at only about 3:12.
So a roof specified at 4:12 is quietly draining its most water-loaded line at 3:12, below the 4:12 the NRCA recommends for shingles and only one step above the 2:12 code floor. It is the reason cross-gabled and cross-hipped roofs leak in the valleys rather than in the open field, and the reason a complex roof should be designed steeper than the minimum rather than at it.
Slope band
Pitch
What it takes
Why
Flat
Under 2:12
Membrane only: TPO, EPDM or modified bitumen
Asphalt shingles are not permitted here. IRC R905.2.2 sets 2:12 as the hard floor for shingles.
Low slope
2:12 to under 4:12
Shingles permitted, with a double layer of underlayment
The double underlayment is a code requirement at this pitch, not an upgrade. Metal and membrane also work well.
Conventional
4:12 to 9:12
Anything: shingles, metal, tile, shake
Walkable for a roofer, standard labor rate, and where most Kansas City homes sit.
Steep slope
Over 9:12
Anything, but installed with fall protection
Harnesses, roof jacks and slower work. Expect a meaningful labor premium over an identical area at 6:12.
Every shape we work on
Twelve forms, drawn on the same footprint so you can compare them directly. Find yours, then read what tends to go wrong with it.
Gable
Very common
Two planes meeting at a central ridge, leaving a triangular wall at each end.
4:12 to 9:12 typical
Works well
Sheds water and snow efficiently
Cheapest shape to frame and to re-roof
Simple ventilation: intake at the eaves, exhaust at the ridge
Generous attic volume for its footprint
Watch for
The gable end is a large flat face for wind to push against
Rake edges peel first in straight-line wind if the starter course was skipped
The default across Johnson County. It performs well here as long as the rake edges are properly started and the ridge caps are purpose-made rather than cut from field shingles.
Hip
Very common
All four sides slope down to the walls, meeting at a ridge shorter than the building.
4:12 to 8:12 typical
Works well
No large flat gable face, so it sheds wind load better than a gable at shallow pitches
Eaves and gutters on all four sides
Self-bracing geometry
Watch for
Four hip lines mean more cap shingles and more places for caps to crack
Less attic space, and ventilation needs more planning
Costs more to frame and to re-roof than a gable of the same area
The dominant form in post-1970s subdivisions here. Worth knowing that the wind advantage shrinks as pitch rises: wind tunnel work found hip and gable peak suction close to equal by about 7:12, which is inside the normal range for these houses.
Cross gable and combination
Very common
Two or more roof sections meeting at right angles, producing valleys where the planes intersect.
Varies by section
Works well
Allows L-shaped and T-shaped floor plans
Architectural interest, dormers, and wings
Watch for
Every intersection creates a valley, and valleys carry more water per foot than anywhere else
More linear feet of flashing means more places to get it wrong
Debris collects where two planes meet
Most larger Johnson County homes are some version of this. When we quote one, the valley count matters more to the price than the square footage does.
Pyramid hip
Occasional
Four triangular planes rising to a single point, with no ridge line at all.
4:12 to 8:12 typical
Works well
Sheds water in every direction equally
No ridge and no gable face, so very little for wind to catch
Works on square footprints, porches and detached garages
Watch for
Four hips converging at one point, and that point has to be capped correctly
Every course is cut, so waste and labor run higher than the area suggests
No ridge means ridge venting is not an option; exhaust has to come from elsewhere
Usually seen here on porch roofs, garages and square additions rather than whole houses. The ventilation question is the one people forget.
Gambrel
Occasional
The barn profile: a steep lower slope and a shallow upper slope on each side.
Lower slope 20:12 or steeper, upper often 4:12 or less
Works well
Maximum usable volume under the roof
Distinctive, and the reason Dutch Colonials look the way they do
Watch for
The shallow upper slope is the weak point and needs proper underlayment for its pitch
The break line between the two slopes is a hinge that must be flashed correctly
Steep lower slopes need fall protection, which raises labor
Uncommon on tract housing but regular on older farm properties and Dutch Colonials in Lawrence and the older parts of the metro.
Mansard
Rare
A near-vertical lower slope on all four sides with a nearly flat deck on top.
Lower slope up to 70 degrees, upper deck often under 2:12
Works well
Turns the top floor into full-height living space
The steep faces suit slate, tile and metal shingles
Watch for
The flat top deck cannot take shingles and needs a membrane
That makes it two different roof systems on one house, meeting at a joint
Drainage on the upper deck is the whole ballgame
You see these on a handful of 1970s builds and commercial conversions. They almost always need a membrane specialist for the top and a shingle crew for the sides.
Shed and skillion
Occasional
A single plane sloping in one direction, with no ridge at all.
3:12 to 15:12, wide range
Works well
Simplest possible roof to build and to inspect
No valleys, no hips, minimal flashing
Ideal for solar because one plane can face south
Watch for
All runoff concentrates along one eave, so the gutter there works hard
Low-pitch versions need the right covering for the slope
Mostly seen on additions, porches, detached garages and modern infill builds.
Flat and low slope
Occasional
A single plane with just enough fall to drain, typically a quarter inch per foot.
Under 2:12
Works well
Usable deck space
Simple, safe access for maintenance
Straightforward for rooftop mechanical equipment
Watch for
Asphalt shingles are not permitted below 2:12, so this needs a membrane such as TPO or EPDM
Ponding water is the primary failure mode
Needs inspecting more often than a pitched roof, not less
Common on commercial buildings across the metro and on a small number of modern homes. The material decision is made by the pitch, not by preference.
Saltbox
Rare
An asymmetric gable, with the ridge set off centre so one slope is much longer than the other.
6:12 to 12:12 typical
Works well
The long slope sheds wind and water well
Colonial character, and extra space under the long side
Watch for
The two slopes age at different rates because they get different sun exposure
The long run needs careful underlayment at the eave
The off-centre ridge sends unequal water to two equal gutters, so the long-slope gutter is usually undersized
Occasional on Colonial revival homes. Worth noting that the south-facing slope will usually wear out first.
Butterfly
Rare
Two planes sloping inward to a central valley, shaped like a pair of open wings.
Low, usually under 4:12
Works well
Striking modern architecture
The central valley can feed rainwater collection
Tall glazing on the outer walls
Watch for
Every drop of water on the roof runs to one internal valley
That valley must never be allowed to clog, freeze or pond
Usually needs a membrane rather than shingles
Very rare here, and honestly a demanding shape for a climate with our freeze-thaw cycling. When we do see one it needs a maintenance plan, not just a roof.
Hexagonal and polygonal
Rare
Six or more triangular planes meeting at a central peak, with a hip running down to every corner.
Often steep, 8:12 and up
Works well
Sheds water in every direction
Strong geometry with no large flat face for wind
Distinctive on gazebos, turrets and octagonal additions
Watch for
Every corner is a hip, so a small roof can have six or more hip lines
Nearly every shingle course needs cutting, which drives labor and waste
Cutting the caps correctly at the peak is the whole job
We get calls for these specifically, usually gazebos, turrets and hexagonal additions, because many crews will not quote them.
Geodesic dome
Rare
A sphere approximated by a lattice of triangles, with no flat plane anywhere on it.
Continuously curved, from near vertical to near flat
Works well
Exceptional structural strength for its weight
Very efficient enclosed volume
No large flat surface for wind to load
Watch for
Asphalt shingles cannot lie flat on a compound curve, so the detailing is unlike any other roof
The pitch changes constantly, so one covering rarely suits the whole dome
Hundreds of triangular seams, each one a potential water path
Skylights and vents interrupt the lattice and need custom flashing
The single most declined roof in the metro. We take these calls because we would rather scope it honestly than tell you to find someone else.
Conical turret
Rare
A cone over a round tower, usually as an accent rather than a whole roof.
Steep, often 12:12 and up
Works well
Sheds water and snow readily
The signature detail on Victorian and Queen Anne homes
Watch for
Continuous curvature means every course is tapered and cut
Where the cone meets the main roof there is a valley that is rarely straight
Steep pitch means fall protection on a small, awkward surface
Found on historic homes in Lawrence, Leavenworth and the older parts of Kansas City. Almost always a specialty repair. For scale, the National Park Service puts an experienced slater at two to three squares a day on clear roof, and under one square a day once dormers, valleys and complex geometry are involved.
The roofs other crews decline
Hexagonal, turret and geodesic dome
People find us by phone for these, usually after being told no a few times. It is worth being honest about why: they are harder, and the difficulty is geometric rather than a matter of effort.
A shingle is a flat rectangle. It lies down happily on a flat plane. On a hexagonal turret every course has to be cut to a taper, and six hip lines converge at a point that has to be capped without leaving a hole. On a geodesic dome there is no flat plane anywhere, the pitch changes continuously from near vertical at the base to near flat at the crown, and the lattice creates hundreds of seams.
So the answer is often not shingles at all. Sometimes it is a membrane, sometimes standing seam or a panel system, sometimes a hybrid where the steep lower band and the shallow crown are treated as two different roofs. We would rather scope that properly than quote something that will fail in five years.
A dome has no flat plane on it anywhere. Every panel meets its neighbours at an angle, and every one of those joints is a place water can find.
What you are seeing, and what it usually means
Most of what homeowners describe as a roof leak turns out to start at a transition rather than out in the open field of shingles. This is roughly how we triage a call.
“Water pouring off the front of the house in a storm”
Usually a clogged gutter, not a roof leak
“Small ceiling stain that grows when it rains hard”
A pipe boot, or a valley above it
“Stain where an upstairs wall meets the ceiling”
Step flashing on a roof-to-wall run
“Wet spot near the fireplace”
Chimney flashing, or a missing cricket
“Icicles, and water dripping in behind the gutter”
An ice dam at the eave
“Drips around a skylight”
Skylight flashing, or condensation from poor attic ventilation
“The wood under the roof edge is going soft”
Soffit and fascia, caused by a gutter or ice dam above
“Shingles in the yard after a storm”
Field shingles or ridge caps, and a question about the starter course
None of this replaces getting on the roof. It does mean that when you call, we can bring the right thing on the truck.
Common questions
What is the most common roof type on houses?
The gable, two planes meeting at a ridge with a triangular wall at each end. It is the cheapest shape to frame, sheds water and snow efficiently, and gives generous attic volume. Across Johnson County the hip roof is close behind, and most larger homes are a combination of the two.
What is the minimum roof pitch for asphalt shingles?
Two in twelve. Under IRC R905.2.2 asphalt shingles may only be used on slopes of 2:12 and greater, and between 2:12 and just under 4:12 a double layer of underlayment is required. Below 2:12 you need a membrane such as TPO, EPDM or modified bitumen, not shingles.
Does roof shape affect how much a replacement costs?
More than square footage does, past a point. Valleys, hips, dormers and changes of pitch all add cut shingles, flashing and labor. Two houses with the same roof area can differ by thousands if one is a simple gable and the other is a cross-gabled roof with three dormers.
Do you work on hexagonal roofs, turrets and geodesic domes?
Yes, and we get calls for them specifically because many crews will not quote them. They are genuinely harder: a dome has no flat plane anywhere on it, so shingles cannot lie flat and the detailing is unlike any other roof. We will scope one honestly and tell you if a different covering makes more sense than shingles.
Which roof shape holds up best in Kansas wind?
A hip roof, but with a caveat most contractors leave out. Wind tunnel research found a hip roof cut worst-case peak suction by up to half compared with a gable, and that finding is where the whole hip-is-better claim comes from. It was measured on 4:12 roofs. Later work testing hip roofs across pitches found the advantage shrinks as the roof gets steeper and is close to gone by roughly 7:12, which is inside the normal range here. Shape also matters less than installation: a properly started and fastened gable roof outperforms a hip roof whose rake edges and ridge caps were cut from field shingles.
How do I know what pitch my roof is?
Pitch is the rise in inches over twelve inches of horizontal run. From the ground you can estimate it by comparison, but the reliable way is from inside the attic with a level and a tape measure, or by having someone measure it during an inspection. Pitch decides what materials are permitted, so it is worth knowing accurately.
Every code figure on this page is checkable. If a claim is a rule of thumb rather than a code requirement, we have said so in the text rather than dressing it up as a standard.
Which code applies to you. Kansas City, Missouri and the State of Kansas have both adopted the 2018 International Residential Code, but Johnson County cities, including Overland Park, Olathe, Lenexa and Leawood, adopt and amend independently and on their own schedules. Treat the sections below as the model code, and confirm the detail with your jurisdiction before making a decision that hinges on it. We pull the permit on every job, so we do that check anyway.
The masonry chimney version of the cricket rule, including the required cricket height for a given chimney width and roof slope. Adds an exception where the chimney intersects the ridge.
Requires a flashing that diverts water away from where the eave of a sloped roof meets a vertical sidewall. This is the kick-out flashing requirement, although the model code never uses that word.
Where a history of ice forming at the eaves exists, an ice barrier must extend from the roof edge to a point at least 24 inches inside the exterior wall line.
The valley-slope rule quoted above, verbatim: where 4:12 planes intersect, the valley runs at about 3:12. Also the NRCA minimums, which are steeper than code for every steep-slope material.
Every roofing contractor working in Kansas must hold a state registration, and the public directory where you can verify ours.
One claim you will not find here: the figure that a fixed percentage of roof leaks originate at flashings. It is repeated across the industry and attributed to the NRCA, but it does not appear in any NRCA publication we could locate, so we have left it out and said only what the NRCA does state, that the joint between a horizontal deck and a vertical surface is the most vulnerable part of any roof.
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