Parts of a roof, explained.

Why it matters: It's the most exposed line on the roof. Wind lifts here first, and on most modern homes it's where hot attic air escapes.

What goes wrong: Cracked or missing ridge caps, caps that were nailed too high and blew off, and gaps in the ridge vent. From the ground, a wavy or sagging ridge line can point to a framing or decking problem.

Ridge caps are often the first shingles lost in high wind and take direct hail hits on both sides.

Why it matters: Hips make a roof sturdier in wind than a flat gable end, but every hip is another seam that has to be capped correctly.

What goes wrong: The same as the ridge: cracked, lifted or missing cap shingles, and caps fastened too close to their edges.

Hip caps stick up above the field shingles, so they catch both wind and hail.

Why it matters: Valleys carry more water than any other part of the roof, often from two big slopes at once, so they need extra protection underneath — typically ice and water shield.

What goes wrong: Shingles cut too short or too long, nails driven too close to the center, debris dams, and worn granules from fast-moving water. Valleys are among the most common leak spots.

Hail and heavy rain concentrate wear here, and debris from storms can block the channel.

Why it matters: Every drop of water that lands on a slope leaves at the eave. The overhang also shades and protects the walls below.

What goes wrong: Rotted decking or fascia from water backing up, missing drip edge, and ice dams in winter. In Kansas City, ice and water shield along the eaves is standard practice for this reason.

Why it matters: Wind gets under roof edges, and the rake is an edge that runs straight up the side of the house.

What goes wrong: Shingles with too little overhang (or too much, so they flap), missing drip edge, and rotted rake boards.

Wind uplift peels shingles from the rake and corners first.

Why it matters: Gable roofs shed water and snow well and leave room for attic ventilation, but their flat ends take wind head-on.

What goes wrong: Gable vents letting in wind-driven rain, siding damage, and short-circuited ventilation when gable vents are mixed with ridge vents.

Why it matters: Everything — decking, shingles, snow, and the roofer walking on it — rests on the framing.

What goes wrong: Sagging, cracked or water-stained lumber, and broken truss plates. A good inspector looks at these from the attic.

Why it matters: Shingles are only as secure as the wood their nails are driven into. Soft or rotted decking means shingles that blow off and roofs that feel spongy underfoot.

What goes wrong: Rot and delamination from leaks or poor attic ventilation, sagging between rafters, and missing gaps or H-clips. Damaged sheets are usually replaced during a re-roof and billed per sheet.

Why it matters: When ice dams form or wind drives rain uphill under the shingles, this is the layer that stops the water. Kansas City winters make it important.

What goes wrong: Left out to save money, not run far enough up the roof, or skipped in valleys. You can't see it once shingles are on — ask for it in writing on any roofing estimate.

Why it matters: It's the backup if water gets past the shingles, and it protects the deck during installation.

What goes wrong: Wrinkles that telegraph through the shingles, torn or brittle felt on older roofs, and seams lapped the wrong direction.

Why it matters: They fill the gaps under the first row of shingles and glue the roof's edges down — the edges are where wind gets underneath.

What goes wrong: Skipped starter, or regular shingles turned upside down so the sealant ends up in the wrong place. Missing starter is a frequent cause of shingles blowing off at the edges.

Properly sealed edges make the biggest difference in high-wind resistance.

Why it matters: They're the first line of defense against rain, sun, hail and wind, and they decide what your roof looks like.

What goes wrong: Granule loss, cracking, curling, blistering, lifted or creased tabs from wind, missing shingles, and hail bruises (soft spots where the mat underneath is fractured).

Hail of about 1 inch and larger can bruise or crack shingles; damage isn't always visible from the ground.

Why it matters: They seal the very top of the roof. Using cut-up regular shingles instead of real cap shingles is a common shortcut that cracks early.

What goes wrong: Cracks along the fold, caps blown off, and exposed nail heads.

The most exposed shingles on the roof in wind and hail.

Why it matters: Without it, water wicks back under the shingles and rots the decking edge and the fascia board. Most building codes now require it.

What goes wrong: Missing drip edge (common on older roofs), pieces that don't overlap, and drip edge installed in the wrong order so water runs behind it.

Why it matters: It closes off the roof edge from weather and animals and carries the weight of full gutters.

What goes wrong: Rot behind clogged gutters or missing drip edge, gutters pulling away, and peeling paint on unwrapped wood.

Why it matters: Walls and chimneys are where water most often gets behind a roof. Step flashing sheds it back onto the shingles one course at a time.

What goes wrong: Missing pieces, one long bent strip used instead of individual steps, rust, and caulk used in place of flashing — a common shortcut that fails within a few years.

Why it matters: Step flashing covers the joint at the roof; counter flashing covers the step flashing. Together they let the chimney and the roof move separately without opening a gap.

What goes wrong: Pulled out of the mortar joint, held only by caulk, cracked mortar, and rust.

Why it matters: Without one, water, leaves and snow pile up behind wide chimneys, and that backside is a classic leak spot. Many codes require a cricket on chimneys wider than 30 inches.

What goes wrong: Missing crickets on wide chimneys, rusted or poorly sealed metal, and debris buildup.

Why it matters: Without it, all the water running down the wall-side step flashing pours straight down the siding and into the wall. It's small, cheap, and prevents some of the most expensive hidden rot in houses.

What goes wrong: Missing entirely — very common on homes built before it became standard — and stains or rot on the wall below the roof edge.

Why it matters: Every plumbing fixture in the house is vented through the roof, and each pipe is a hole that has to stay sealed.

What goes wrong: The rubber collar cracks in the sun, usually years before the shingles wear out. A cracked boot is one of the most common roof leaks — and one of the cheapest to fix.

Hail can split the rubber collar and dent the base.

Why it matters: Ridge and box vents can only pull hot, moist air out if cool air can get in down low. Blocked soffits cook shingles from underneath and breed condensation and frost in winter.

What goes wrong: Vents blocked by insulation, painted shut, or never cut through; damaged panels letting in animals.

Why it matters: Hot, humid attic air rises and leaves through the ridge. Good ventilation keeps shingles cooler in summer and prevents condensation and ice dams in winter.

What goes wrong: A slot that was never cut, vents crushed or blocked, and mixing ridge vents with box or gable vents, which can short-circuit the airflow.

Why it matters: They let hot attic air escape on roofs without a ridge vent.

What goes wrong: Too few for the attic size, cracked plastic, and hail dents in metal vents.

Dented metal vents are one of the first things inspectors check to gauge hail size.

Why it matters: They keep water away from your foundation, siding, windows and landscaping. Overflowing gutters can also back water under the roof edge.

What goes wrong: Clogs, sagging or loose hangers, leaking joints, and pitch that lets water stand. Shingle granules collecting in gutters are a sign of wear.

Dents in gutters help show how large and dense the hail was.

Why it matters: A gutter is only as good as its downspouts. Each one drains a section of roof.

What goes wrong: Clogged elbows, disconnected sections, and water dumped right next to the foundation.

Dents and crushed elbows are common after hail.