Quick answer
A ridge cap is the row of shingles bent over the peak of a roof, and over its hips, to seal the joint where two roof planes meet. Most are made from hip and ridge shingles, a separate product sold just for this job.
On many roofs the ridge cap also covers a ridge vent. It is priced by the linear foot on most quotes.
Quick facts
- Also called
- Hip and ridge shingles, cap shingles
- Order of work
- Hips first, then the ridge 1
- Example exposures
- 5 in (CertainTeed Shadow Ridge), 6 in (Owens Corning ProEdge), 8 1/4 in (IKO UltraHP) 124
- Example coverage
- 30 linear feet per bundle (CertainTeed Shadow Ridge) 4
- Nails
- Same code rule as field shingles: 12-gauge, 3/8 in head, 3/4 in into the deck 5
Key takeaways
- A ridge cap is the line of folded shingles that covers the peak and the hips of a roof.
- Hip and ridge shingles are a separate product made for this job. They are not the same as the shingles on the rest of the roof.
- Each cap product has its own install sheet with its own exposure, nail spots and vent rules.
- Cap shingles carry their own wind rating. CertainTeed lists ASTM D3161 Class F for its Shadow Ridge cap.
- Quotes usually price the ridge cap by the linear foot. Check that hips and ridges are both measured.
What a ridge cap is
Every sloped roof has lines where two planes meet at an outside corner. The top line is the ridge, the peak of the roof.
On a hip roof, the sloped corners that run from the peak down to the eaves are called hips. These lines are where the field shingles stop. Something has to cover the gap and shed water off both sides. That something is the ridge cap.
A ridge cap is built from short pieces of shingle that are bent over the line and laid one over the next, like the field shingles but running along the ridge.
Each piece covers the nails of the one before it. The last piece at the end is nailed through the face, and its nail heads are sealed with roof cement 1.
Most roofers now use hip and ridge shingles for this. These are made just for caps. CertainTeed describes its Shadow Ridge accessory shingles as used to finish the hips and ridges of your roof 4.
IKO says its UltraHP product is designed for use as hip and ridge shingles only 2. Owens Corning's ProEdge comes perforated so each piece separates into three cap shingles 1.
How a ridge cap works
Water runs down a roof. At the ridge, it has nowhere to come from except the sky, so the cap's job is to keep rain and wind-driven water from getting in at the top joint.
Each cap piece overlaps the one before it, and the exposed part points away from the prevailing wind. That way wind pushes over the laps, not under them.
That is why the install sheets say where to start. Owens Corning says to apply the ridge after the hips, beginning on the end of the ridge opposite the prevailing wind direction 1.
IKO says to begin at the bottom of the hip, or at the end of the ridge opposite the prevailing winds 2.
The cap is held two ways, like the field shingles. Nails hold each piece down, and a sealant strip bonds it to the piece below.
The Owens Corning sheet warns not to put nails in the sealant strip 1.
In high wind areas, IKO says to seal each UltraHP piece down with two 1-inch spots of roofing cement 2.
The ridge is also where warm, damp attic air wants to leave. On many roofs a slot is cut in the deck along the peak and a ridge vent is laid over it. The cap shingles then go on top of the vent, hiding it and keeping rain out while air escapes from the sides.
- Cap shinglesLapped away from the prevailing wind, nailed clear of the sealant strip 1
- Ridge ventLaid over the slot; must not be wider than the cap allows 2
- Field shinglesFinished up to the ridge before any cap goes on 1 2
- Slot in the deckCut along the peak so attic air can leave
- AtticWarm, damp air rises and exits through the vent sides
On an unvented ridge the stack is the same minus the slot and the vent; the cap still has to shed wind-driven rain on its own.
Types of ridge cap
Ridge caps come in a few forms. Check the field shingle maker's list of matching caps, since the cap is part of the roof system.
| Type | What it is | Notes |
|---|---|---|
| Pre-cut hip and ridge strips | Flat strips perforated to split into pieces, bent over the ridge on site | Owens Corning ProEdge splits into three pieces 1 |
| Pre-formed or high-profile caps | Thicker pieces made to sit over the ridge without hand bending | IKO UltraHP needs no hand bending 2 |
| Single-layer accessory cap | One layer that can be doubled for a heavier look | CertainTeed Shadow Ridge can be double-coursed 4 |
| Cut 3-tab shingles | Field shingles cut into pieces and bent over the ridge | Check whether the shingle maker allows it |
| Metal ridge cap | Formed metal trim along the ridge of a metal roof | Made by the panel maker; see metal roofing |
| Tile or slate ridge | Special ridge tiles set in mortar or on fasteners | Follows the tile or slate maker's rules |
Cap shingles also come in impact-rated versions. IKO says its UltraHP IR should be used with impact resistant shingles 2.
Why hip and ridge shingles are a separate product
Laminated architectural shingles are thick and stiff. They are built to lie flat, not to fold over a sharp ridge. Bend one and the layers can crack.
So makers sell a separate cap product that is made to bend, or that comes pre-shaped.
IKO's Cambridge instructions recommend its own pre-cut hip and ridge products or the pre-formed UltraHP for hips and ridges 3.
Caps are also tested on their own. CertainTeed lists its Shadow Ridge cap as UL Class A for fire and ASTM D3161 Class F for wind 4. The cap is a product with its own labels, not just leftover field shingles.
Matching matters for warranties too. CertainTeed says Shadow Ridge accessory shingles carry the same warranty as the shingles they are applied over 4. A cap from another maker, or cut field shingles, may not carry that link. Read the warranty terms for your shingle line before choosing.
Worked example: reading the ridge cap line on a quote
Say a quote lists 60 linear feet of ridge and 80 linear feet of hips for a hip roof, using CertainTeed Shadow Ridge. Here is how the numbers work, using the maker's coverage figure 4.
| Step | What you check | Result |
|---|---|---|
| 1 | Total cap length | 60 ft of ridge + 80 ft of hips = 140 linear feet |
| 2 | Coverage per bundle | CertainTeed lists 30 linear feet per bundle |
| 3 | Bundles needed | 140 ÷ 30 = 4.67, so 5 bundles before waste |
| 4 | Double course? | If the cap is doubled for looks, the bundle count roughly doubles |
| 5 | Ridge vent | If a ridge vent is planned, check its length is listed as its own line |
Coverage varies by product, so use the number on the bundle you are buying. The point of the check is that hips and ridges are both measured and that the bundle count makes sense for the length.
Where ridge caps go
Caps cover every outside corner line on a shingle roof: the main ridge, any smaller ridges on dormers or wings, and every hip. A plain gable roof has only a ridge.
A hip roof has a short ridge and four long hips, so it uses far more cap. Our roof pitch guide explains how slope changes the length of hips.
Caps do not go in valleys, which are inside corners where water flows together. Those need valley flashing or a woven or cut valley instead.
Some makers allow caps at the rake edges too. IKO says UltraHP may also be installed at gable and rake edges for added roof definition 2. That is a look choice, not a code rule.
On a ridge vent, the vent sits on the deck over the slot, and the cap goes over the vent.
IKO says that when UltraHP is used with a ridge vent, the vent must be 9 inches wide or less 2.
CertainTeed says Shadow Ridge can go on shingle-over vents or right over the centerline of the hip or ridge 4.
What a good ridge cap does
- Seals the top joint of the roof against rain and wind-driven water
- Covers the nails at the top of the field shingles
- Hides and protects a ridge vent while letting air out the sides
- Adds a wind-rated layer on the most exposed line of the roof 4
- Can match the warranty of the field shingles when the maker's cap is used 4
- Gives the roof a clean, finished line from the street
Limitations
- The ridge takes the strongest wind on the roof, so caps are a common place for blow-offs.
- Cap pieces can crack if bent in cold weather. Owens Corning warns that shingles break easily below 40°F 1.
- The last piece has exposed nails that rely on roof cement, which ages 1.
- Not every ridge vent fits under every cap. IKO limits vent width under UltraHP to 9 inches 2.
- A cap from a different maker may not share the field shingle warranty.
What drives the cost of a ridge cap
We do not list prices. Most quotes show the ridge cap as its own line, priced by the linear foot. These are the things that move it. For a full estimate, try our roof cost calculator.
- Total length. Hip roofs need far more cap than gable roofs of the same size.
- Product. High-profile and impact-rated caps usually cost more than pre-cut strips.
- Double coursing. A doubled cap uses about twice the material 1.
- Ridge vent. Adding or replacing a ridge vent is a separate item.
- Pitch and height. Steep or tall roofs slow the work along the peak.
- Tear-off. On a roof over an old one, Owens Corning says to remove the old hip and ridge shingles first for a level job 1.
How a ridge cap is installed
A licensed roofer does this work. These steps come from the makers' sheets and are for checking the job, not a how-to.
- The field shingles go on first. Both Owens Corning and IKO say to finish the field before the caps 1 2.
- If there is a ridge vent, the slot is cut in the deck and the vent goes on.
- Hips are capped first, starting at the bottom of each hip 1 2.
- The ridge is capped next, starting at the end opposite the prevailing wind 1.
- Each piece is laid at the maker's exposure and nailed in the maker's spots, clear of the sealant strip 1.
- The last piece is face-nailed and the nail heads are covered with roof cement 1 3.
Looking after a ridge cap
The ridge cap is the easiest part of the roof to see from the ground, so it is a good place to start any check.
After a big wind, look along the peak with binoculars. Missing pieces, lifted edges, or a gap where the vent shows through all mean the cap needs work. Do not climb up to look.
The roof cement over the last nails can dry out and crack with age. A roofer can reseal it during a routine visit.
If you have a ridge vent, check from the attic on a sunny day.
Look for water stains on the deck under the vent slot, which can point to a leak at the cap.
Replacing a few blown-off caps is a common small repair. Ask the roofer to match the product, so the wind rating and warranty stay in line.
Ridge cap problems to watch for
- Wrong start direction. Caps laid into the wind can lift at the laps 1.
- Nails in the sealant strip. Owens Corning warns against it 1.
- Raised or crooked nails. They stop the cap from sealing and can lead to blow-off 1.
- Cracked caps. Laminated field shingles bent over a ridge, or caps bent in the cold, can crack 1.
- Vent mismatch. A vent wider than the cap allows leaves edges exposed 2.
- Short nails. Cap nails pass through more layers, so they must be long enough to reach the deck depth the code asks for 5.
If caps keep blowing off, ask a roofer to check the nailing and the vent fit. Our roofing nails guide covers the nail rules. For storm losses, see storm damage and insurance.
What the code requires
The 2021 International Residential Code does not have a separate ridge cap section. Caps on an asphalt roof fall under the asphalt shingle rules, and the code hands most details to the maker's instructions. Your state or city may use a different edition or change parts of it.
| Rule | What the code says |
|---|---|
| Wind class (R905.2.4.1) | Asphalt shingles tested to ASTM D7158 and labeled for the design wind speed; shingles outside D7158's scope tested to ASTM D3161 5 |
| Fasteners (R905.2.5) | Corrosion-resistant roofing nails, 12-gauge shank, 3/8 in head, ASTM F1667, 3/4 in into the deck or through it 5 |
| Attachment (R905.2.6) | The maker's number of fasteners, and at least two per individual shingle 5 |
| Maker's instructions | Exposure, nail spots, start point and vent rules come from the cap maker 1 2 |
| Fire class | Owens Corning says all exposed material must be UL Class A to keep a Class A system 1 |
Wind ratings on cap shingles
Ridge caps sit on the most exposed line of the roof, so their wind rating matters.
NRCA explains that ASTM D3161 sorts shingles into Class A, D and F for wind speeds of 60, 90 and 110 mph, and that ASTM D7158 uses Class D, G and H for basic wind speeds of 115, 150 and 190 mph 6.
The two tests use different kinds of wind speed, so the numbers are not directly comparable.
CertainTeed lists Shadow Ridge as ASTM D3161 Class F 4. Its product sheet also lists a 15-year 110 mph wind warranty, with an upgrade to 130 mph available 4.
Those are CertainTeed's figures for that product, on that sheet. Other caps carry other ratings. Ask your roofer which cap they will use and what its bundle label says.
Ridge cap vs related parts
| Ridge cap | Ridge vent | Starter strip | |
|---|---|---|---|
| What it is | Folded shingles along the peak and hips | A vent along the peak under the cap | A strip shingle along the eaves and rakes |
| Job | Seals the top joint | Lets attic air out | Seals the first course at the edges |
| Where | Ridge and hips | Ridge only | Eaves and rakes |
| Order | Last | Before the cap | First |
| Priced as | Linear feet | Linear feet | Linear feet |
Common misconceptions
- Myth Ridge caps are just leftover shingles.
- Reality Most makers sell a separate hip and ridge product with its own labels 4 2.
- Myth Any cap works over any vent.
- Reality Caps have vent rules. IKO limits vent width under UltraHP to 9 inches 2.
- Myth It does not matter which end you start.
- Reality Makers say to start at the end opposite the prevailing wind 1 2.
- Myth The cap has the same wind rating as the roof.
- Reality The cap carries its own rating on its own label 4.
- Myth The ridge cap is included in the per-square price.
- Reality Many quotes list it as its own linear-foot item. Ask if it is in or out.
Local rules and climate
Each state or city adopts its own code edition and can add to it.
The wind class your shingles need depends on the design wind speed for your area 5, and caps are the first thing to go in a strong wind.
In high wind areas, IKO calls for hand-sealing each cap with roof cement 2. Ask your roofer what your local wind speed is and which cap rating fits.
Cold weather matters for install. Owens Corning warns that shingles break easily below 40°F 1, and IKO suggests storing caps in a heated area before cold-weather use so they bend more easily 3.
In hail areas, an impact-rated cap such as IKO's UltraHP IR is made to pair with impact-resistant field shingles 2. Your building department can tell you which rules apply at your address.
What to ask your roofer
- Which hip and ridge product will you use, and is it made by the same maker as the field shingles?
- What wind rating is on the cap's bundle label?
- How many linear feet of ridge and hips did you measure?
- Is the ridge cap priced in the per-square rate or as its own line?
- Are we adding or keeping a ridge vent, and does it fit the cap maker's rules?
- Will the cap be single or double, and does that change the price?
Keep going
- Roof repairFix blown-off ridge caps
- Roof replacementCaps go on last in a new roof
- Choosing a rooferCompare quotes line by line
- Roofing cost guideWhat moves the price of a new roof
Questions about ridge cap
What are hip and ridge shingles?
Hip and ridge shingles are cap shingles made to cover the peak and hips of a roof. They bend over the joint where two roof planes meet, or come pre-shaped to fit it. Makers sell them separately from field shingles. CertainTeed, IKO and Owens Corning each publish their own install sheets for them.
Is a ridge cap the same as a ridge vent?
No. A ridge vent is a vent laid along the peak over a slot in the deck so attic air can escape. A ridge cap is the row of shingles that goes over the top. On a vented roof the cap covers the vent. On an unvented ridge the cap simply seals the joint.
Can you use regular shingles for a ridge cap?
Sometimes, but makers often recommend their own cap product. Some roofers cut 3-tab shingles into cap pieces, so check the maker's sheet first.
Laminated architectural shingles are stiff and can crack when bent over a ridge.
IKO, for example, recommends its pre-cut hip and ridge products or UltraHP for the hips and ridges on its Cambridge shingle.
How is a ridge cap priced?
Most quotes price it by the linear foot, as its own line. The roofer measures the ridge and all the hips and adds them up. Hip roofs need much more cap than gable roofs. Ask whether the cap is in the per-square price or separate, and whether a ridge vent is listed apart.
How many linear feet does a bundle of ridge cap cover?
It depends on the product. CertainTeed lists 30 linear feet per bundle for its Shadow Ridge cap at a 5-inch exposure. Other caps have other exposures, such as 6 inches for Owens Corning ProEdge and 8 1/4 inches for IKO UltraHP, so coverage differs. Use the figure on the bundle you buy.
Which way should ridge cap shingles face?
Away from the prevailing wind. Owens Corning says to start the ridge at the end opposite the prevailing wind direction, and IKO says the same. That way the exposed ends point downwind, and wind blows over the laps instead of into them. Hips start at the bottom and run up.
Do ridge caps have a wind rating?
Yes, many do, on their own label. CertainTeed lists its Shadow Ridge cap as ASTM D3161 Class F. Its sheet also lists a 15-year 110 mph wind warranty with an upgrade to 130 mph available. Other caps carry other ratings, so ask which cap your roofer will use.
Why do ridge caps blow off?
The ridge takes the strongest wind on the roof. Caps blow off most often when nails are raised, crooked or placed wrong, when the cap was laid facing into the wind, or when it never sealed. Owens Corning warns that raised nails can cause sealing failure and blow-off. A roofer can find the cause.
Can a ridge cap go over any ridge vent?
Not always. Each cap maker sets vent rules. IKO says a ridge vent used with its UltraHP cap must be 9 inches wide or less. CertainTeed says its Shadow Ridge cap can go on shingle-over vents. Check both the cap and the vent maker' sheets.
Do you replace the ridge cap on a reroof?
Yes. A new roof gets a new ridge cap. Even when a new layer goes over an old roof, Owens Corning says to remove the old hip and ridge shingles first so the new cap lies level. A ridge vent may be reused or replaced, depending on its condition and the cap maker's rules.
Sources
- Owens Corning, ProEdge Hip & Ridge Shingles Installation Instructions (September 2024), retrieved .
- IKO, UltraHP Hip and Ridge Application Instructions (English, rev. 01/24), retrieved .
- IKO, Cambridge Shingles Application Instructions (English, rev. 01/21), retrieved .
- CertainTeed, Shadow Ridge Hip & Ridge Accessory Shingles product sheet, retrieved .
- International Code Council, 2021 International Residential Code §R905.2.4.1, §R905.2.5, §R905.2.6 (Maryland adoption, read at UpCodes), retrieved .
- Mark S. Graham, "Understanding asphalt shingle standards," Professional Roofing (NRCA), February 2021, retrieved .
Expert review
Written by the HyreRoof editorial team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Cap install rules read in Owens Corning, IKO and CertainTeed documents and labelled as theirs; code text read in the 2021 IRC as adopted in Maryland; wind classes from NRCA.
Suggest a correction. We fix errors and say what changed.