What Is A Valley On A Roof?

What Is A Valley On A Roof
What is a roof valley? – A roof valley is when two roof facets meet at a slope to form an interior angle. The main purpose of roof valleys is to allow water to flow down your roof properly. There are two common types of roof valleys, open and closed. The names of the valleys pretty much tell you exactly what they are. What Is A Valley On A Roof (Left: closed valley, Right: open valley) Open valleys mean they are literally “open,” and there’s no roofing material installed over the valley. On the other hand, closed valleys are “closed” by the roofing material (asphalt shingles) installed over the valley.

Why is my valley leaking?

Often when your roof valley is leaking, the true cause is the membrane or underlay beneath your roofing materials. As these membranes are often not expected to last as long as the tiles above, they can become damaged far sooner and lead to roof leaks and other issues.

What do you call the valleys on a roof?

Table of Contents

  1. Shingle Roof Valley Types: Quick Reference Chart
  2. Shingle Roof Valley Types
  3. Which Type of Roof Valley is Recommended?
  4. When Should Your Roof Valley be Repaired?
  5. Roof Valley Flashing Materials
  6. Roof Valley Flashing Profile
  7. Keeping Your Roof Valley in Good Condition
  8. Why Focus on Your Roof’s Valley?

NOTE: IKO recommends open metal valleys for best roof performance. All other valley types are not covered by IKO’s limited warranty. A roof valley is a spot where two roof surfaces meet. Each roof plane has a layer of shingles that need to smoothly intersect at the valley, even though they are laid at slightly different angles. The roof valley is a challenging part of the roof to install. The water from both roof planes is channeled into the valley, so it carries the most water. Therefore, the roof valley will see the most wear and is the second most likely spot on a roof to develop a leak.

Manufacturers may require you to have a certain roof valley type in order to be covered by their limited warranty. So, your choice of roof valley installation method is critical to maintain your warranty and get the best longevity from your roof. There are three main types of roof valleys: woven roof valley, closed roof valley and open roof valley.

There’s also a subtype of open metal valley, called a California valley. Each type has its own benefits and drawbacks. We’ve compiled a quick chart that will help you understand the fundamental differences between them. After the chart, we’ll go into detail about each type of roof valley, how to keep your valley well-maintained and what your options are if you need roof valley repair.

What is the valley on a tiled roof?

What Is A Roof Valley? | Sandhurst Roofing | Roofing Services Roof valleys are the troughs that form where two roof slopes meet. Their purpose is to collect water and move it away from the roof to a gutter.

What is the opposite of a valley on a roof?

Hip & Ridge – A roof “hip” refers to the outwards diagonal joint created by the junction of two roof slopes. What Is A Valley On A Roof A roof “ridge” refers to the upper most peaks created by the junction of two roof slopes facing opposite directions. In the age where 3-tab shingles were the standard in roofing, it was common practice to take the same shingle used to cover the roofing slopes, cut it into 3 pieces and use it to protect your hips and ridges.

Today, where laminate products are the overwhelming shingle of choice, specific shingles are manufactured for the hips and ridges. It is still OK to use a 3 tab shingle if you can find a colour to match your shingle of choice, but it is recommended by manufacturers to use specialty cap shingles for laminate and designer products to compliment their enhanced warranties.

Hip and Ridge cap shingles are traditionally a single layer shingle, but manufacturers are now producing double layered shingles, and even shingles that are folded to create superior strength and design.

How long do roof valleys last?

FULL REPLACEMENTS – A full valley replacement is a big job, involving a significant amount of work and cost compared with a simple repair. The tiles surrounding the valley will need to be removed as well as the underfelt, and possibly some timber section below.

  • These materials will all be replaced with the new valley in mind, so it sits flush in the right place.
  • The removed tiles can be replaced with new cement.
  • A replacement can be done within half a day with two workers, but of course, it depends on the size of the section so there is some variance.
  • At best, roof valleys can last 20 years.

It’s highly dependent on the materials used, the quality of the installation, the location of the house, the weather, and so on. Small leaks that can be quickly repaired don’t necessarily mean your valleys are in desperate need of replacing, but we can always advise on your best course of action.

Should roof valleys be sealed?

Scope Install a self-sealing membrane in roof valleys and around penetrations to minimize the possibility of roof leaks.

  • Choose a self-sealing membrane such as a bituminous peel-and-stick material or equivalent at all valleys and roof deck penetrations.
  • In valleys, install this layer directly on the roof sheathing surface beneath the roofing felt.
  • Around penetrations such as pipes or vents, install one piece to surround the pipe from the down-slope side of the pipe, then install the upslope piece to overlap the upper edge of the down-slope side. Integrate with the roofing underlayment.
  • Building code requirements for roof valley flashing vary by roofing material type.

See the Compliance Tab for related codes and standards requirements, and criteria to meet national programs such as DOE’s Zero Energy Ready Home program, ENERGY STAR Certified Homes, and EPA Indoor airPLUS, Description The roof is the house’s primary defense against water intrusion from rain, snow, and ice.

This “lid” of the home must be structurally sound and must be designed and constructed to shed water effectively and consistently through all seasons, extreme weather events, and atmospheric conditions. Water that leaks into the house through the roof can quickly damage insulation, create conditions for mold growth and pest invasion, and even set into motion structural rot.

Over time even the smallest leak in a roof can result in a significant amount of water damage, and not just in the attic. Once inside the home, water can travel laterally as well as vertically along framing members to cause damage in ceilings, walls, floors, and even basements.

Valleys and penetrations through the roof decking are among the most vulnerable areas for water intrusion. Valleys should be carefully sealed along the entire length. To help prevent water entry at these vulnerable points, install a self-sealing bituminous membrane or the equivalent along all valleys and properly integrate this membrane into the adjoining roofing materials.

Self-sealing membrane should also be installed, along with flashing, around all penetrations through the roof including direct penetrations like plumbing stack vents and structural penetrations like dormer windows and chimneys. Sheathing seams should be sealed with a compatible tape.

Most roofing membranes are made of a heavy, flexible bituminous material that has been impregnated with a petroleum-based solution like tar which makes the material waterproof. Most membrane products come with a “peel and stick” adhesive backing. When properly installed these products provide long-lasting protection from water intrusion.

Note: The U.S. Environmental Protection Agency (EPA) uses the phrase “or equivalent” to indicate that a variety of products can be used. Regardless of the product’s composition, it must be water impermeable and must durably adhere to the roof deck. Please check with the manufacturer’s material classifications and installation instructions to ensure the material you choose will adequately protect the roof from water intrusion ( EPA 2011 ).

Building codes generally do not require a sealed roof deck for new homes or roof replacements, but a sealed roof deck is beneficial in any area and is particularly recommended in hurricane-prone or high-snow-load regions. Sealed roof deck valleys and sealed penetrations are components of a sealed roof deck.

Note: The U.S. Environmental Protection Agency (EPA) uses the phrase “or equivalent” to indicate that a variety of products can be used. Regardless of the product’s composition, it must be water impermeable and must durably adhere to the roof deck. Please check with the manufacturer’s material classifications and installation instructions to ensure the material you choose will adequately protect the roof from water intrusion. Figure 1. Peel and stick membrane applied to roof valley. These workers are properly installing a self-sealing bituminous membrane to a valley on the roof deck. Note the material is centered along the valley to ensure maximum protection. (Source: EPA Indoor airPLUS, 2020.) How to Install Self-Sealing Bituminous Membranes along Valleys of Roof Decks

  1. Clean the roof deck sheathing along the valley to ensure it is free of loose nails, wires, and debris. Although the membrane is made from relatively strong material, it can be torn or punctured. Make sure the area is dry and free of oil and dust to ensure the membrane will adhere properly.
  2. Measure the length of the valley to be covered.
  3. Cut the self-sealing bituminous membrane to length. For extremely long valleys, cut the material in shorter, more manageable lengths.
  4. Install metal drip if required or desired for wild fire and hurricane resistance. Install self-adhering bituminous membrane along roof eave as required by code or desired to reduce risk of water damage from ice dams.
  5. Install the membrane directly on the roof sheathing material (typically OSB). Apply from the lowest point to the highest, overlapping membrane sections by 6 inches in shingle fashion to allow water to flow unobstructed down the length of the valley. The membrane must be straight and centered with the valley line. Installation note : Some peel-and-stick membrane products come with a lengthwise split along the protective backing that can give you a guideline for centering the product while you peel and install it along first one side of the valley then the other.
  6. Make sure the membrane lays flat with no gaps, creases, or folds. Secure the material in place with a heavy roller.
  7. Install the membrane and continue with installation of the roof cladding. (See Figure 2. Fasteners should not be located within 6 inches of the valley center.)
  8. If installing a shingle roof cladding, metal valleys are recommended over woven or abutted shingle cladding in valleys.

Figure 2. Use bituminous seal-sealing membrane to seal roof valleys. The self-adhesive membrane is installed directly on the plywood roof deck beneath the underlayment (roofing felt) and shingles. (Source: EPA Indoor airPLUS, 2020.) How to Install Self-Sealing Bituminous Membranes around Direct Penetrations in the Roof

  1. Clean the roofing area after the pipe or vent has been installed through the roofing deck. Make sure roof deck around the penetration is free of loose nails, wires, debris, dust, oil, or water.
  2. Starting at the eave side of the roof below the penetration, install the underlayment (roofing felt) up to the penetration.
  3. Measure the area to be covered and cut a piece of membrane to fit around the lower half of the penetration, allowing for at least 6 inches of membrane on each side and below the penetration. See Figure 3.
  4. Install the self-adhesive membrane so that it seals tight around the pipe and laps over the roofing felt, as shown in Figure 3. Use a heavy hand roller to secure in place. Some manufacturers require that a primer be applied before the membrane is installed, particularly during cold weather or damp conditions.
  5. Measure and cut a piece of membrane to fit around the upper side of the pipe. A flexible-type membrane like flashing tape is ideal for flashing around pipes. Install so that it seals tightly around the pipe and the edges overlap the top edge of the first piece of membrane, as shown in Figure 3.
  6. Continue installing underlayment above the penetration to overlap this membrane.
  7. Install shingles or roofing material up to the penetration.
  8. Install a pre-manufactured pipe flashing over the pipe and shingles, as shown in Figure 4 and Figure 5.
  9. Continue installing shingles above the pipe to cover the top edge of the flashing.

Figure 3. Seal around piping and other roof penetrations with self-sealing bituminous membrane that is layered shingle-fashion with the roof underlayment. (Source: EPA Indoor airPLUS, 2020.) Figure 4. Install a pre-manufactured pipe flashing cap around the pipe and integrate installation so that the upper edge of the flashing is covered by rows of asphalt shingles above the piping. (Source: EPA Indoor airPLUS, 2020.) Figure 5. Integrate pre-formed vent pipe flashing, shingle-fashion, with roofing underlayment and shingles. (Source: Home Innovation Research Labs, 2020.) How to Seal around Structural Penetrations and Roof-Wall Junctures

  1. Clean the roofing area after the dormer or other structure has been installed through the roofing deck. Make sure the roof deck around the structure is free of loose nails, wires, debris, dust, oil, or water.
  2. Install underlayment to lap up the vertical wall at least 8 inches and secure in place. Alternatively, install the underlayment to the vertical wall and install self-adhesive membrane over the underlayment and up the wall at least 8 inches.
  3. Install the step flashing and kick-out flashing and secure in place.
  4. Apply self-adhesive membrane material directly over the vertical rise of the step flashing and up the side of the penetration.
  5. Install the WRB material over the peel and stick, securing it in place and attaching it to the membrane with tape.
  6. Continue installing the roofing material.
  7. Alternately, the self-adhering membrane can be installed prior to the step flashing as described in the guide Step and Kick-Out Flashing at Roof-Wall Intersections, Apply to the roof deck and lap up side wall, install metal step flashing, cover top of metal flashing with self adhesive tape flashing, install house wrap and siding over tape flashing.
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Figure 6. Protect roof-wall intersections, as required for structural roof penetrations such as dormers or a framed chimney, with step flashing and self-adhesive bituminous membrane. Ensuring Success To ensure that the roof valleys and penetrations are well sealed, the area must be cleaned prior to installation of the self-adhesive bituminous membrane.

  1. Only a complete seal will help keep water from finding a way through the valley and entering the house.
  2. Also, once applied, the membrane must be rolled flat so that no folds or creases are present.
  3. Climate Hurricane-Prone Regions Roofing and wall cladding are more likely to be damaged or lost in hurricane-prone regions and other high-wind areas, leaving flashing and underlayment exposed and more susceptible to wind and water intrusion.

Proper installation of flashing and sealing products is even more important in these areas to protect against storm damage. The IRC does not have additional requirements for roof-wall flashing in hurricane-prone regions or other high-wind areas. Some local jurisdictions may have additional requirements or require specific product approval.

Building codes establish minimum requirements, but products must also be installed in accordance with manufacturer’s instructions. This is important because codes typically do not provide all the detailed information for a durable installation. Assessments by FEMA after hurricanes commonly find that water intrusion and structural building failures are due to improper installation of building components.

So, even where the IRC does not require additional measures, proper installation is more critical in hurricane-prone regions. The Insurance Institute for Business and Home Safety ® (IBHS) offers guidance, best practices, and voluntary construction standards and programs for building in disaster-prone areas including hurricane and other high-wind zones.

  1. The IBHS FORTIFIED Roof program includes options for sealed roof decks.
  2. IBHS also provides specific guidance for flashing including roof valley flashing.
  3. Sealing the roof deck at valleys and penetrations and proper sealing of the roof deck using self-adhesive membrane and underlayment can significantly prevent water infiltration through the roofs during hurricanes when the primary roofing is damaged.

See the Hurricane Technical Summary for New Construction by the IBHS Fortified Home program for all of the methods that can be adopted for sealing roof decks. High Snow Load Regions In areas with deep or sustained snow cover (Figure 1), extra protection of roof valleys as shown in this guide, is recommended. Figure 1. Design Snow Loads Map for the United States, adapted from ASCE 7-10, Figure 7-1 (Source: Medeek Design 2015 ). The Compliance tab contains both program and code information. Code language is excerpted and summarized below. For exact code language, refer to the applicable code, which may require purchase from the publisher.

While we continually update our database, links may have changed since posting. Please contact our webmaster if you find broken links. ENERGY STAR Certified Homes, Version 3/3.1 (Rev.09) Water Management System Builder Requirements 3. Water-Managed Roof Assembly.3.3 Self-adhering polymer-modified bituminous membrane at all valleys & roof deck penetrations.3, 16 Footnote 4) Not required in Dry (B) climates as shown in 2009 IECC Figure 301.1 and Table 301.1.

Footnote 15) As an alternative, any applicable option in 2009 IRC Section R905.2.8.2 is permitted to be used to meet Item 3.3 and any option in 2009 IRC Section R905.2.7.1 is permitted to be used to meet Item 3.4. EPA recommends, but does not require, that products meet ASTM D1970.

In addition, any option in 2009 IRC Section R905.13 is permitted to be used to meet either Item 3.3 or 3.4. Please see the ENERGY STAR Certified Homes Implementation Timeline for the program version and revision currently applicable in your state. DOE Zero Energy Ready Home (Revision 07) Exhibit 1 Mandatory Requirements.

Exhibit 1, Item 1) Certified under the ENERGY STAR Qualified Homes Program or the ENERGY STAR Multifamily New Construction Program.2009, 2012, 2015, 2018, and 2021 International Residential Code (IRC) Section R905.3.8 Flashing. Flashing and counterflashing to be provided at the juncture of roof vertical surfaces per manufacturer’s instructions.

If metal, it cannot be less than 0.019 inch (No.26 galvanized sheet gage) corrosion-resistant metal. Valley flashing must extend at least 11 inches from the centerline each way and have a splash diverter rib not less than 1 inch high at the flow line formed as part of the flashing. Sections of flashing must have an end flap at least 4 inches.

For 3/12 roofs and greater, valley flashing must have a 3-ft wide underlayment of one layer of Type I underlayment running the full length of the valley, in addition to any other required underlayment. Metal valley flashing underlayment must be solid-cemented to the roofing underlayment for slopes less than 7/12 or be self-adhering polymer modified bitumen sheet in areas where the average daily temperature in January is 25°F.

Section R905.2.8.2 Valleys – For asphalt roofs, open valleys (valley lining exposed) should be lined with a strip of corrosion-resistant metal (listed in Table R905.2.8.2) that is at least 24 inches wide or two layers of mineral–surfaced roll roofing with the bottom layer strip at least 18 inches wide and the top layer at least 36 inches wide.

For closed valleys (where the valley is covered with shingles) the valley should be lined as described for open valleys or with one ply of smooth roll roofing at least 36 inches wide or with self-adhering polymer modified bitumen complying with ASTM D1970.

  • Requirements vary for other roofing types.
  • See Section R905.4.6 for metal roof valley flashing requirements, Section R 905.6.6 for slate roof valley flashing, Section R 905.7.6 for wood shingle roof valley flashing, and Section R 905.8.8 for wood shake roof valley flashing.
  • Section R905.1.2 (Section R905.2.7.1 in 2012 and 2009) specifies ice barrier requirements for geographic areas where there has been a history of ice dams.

Requirements apply to asphalt shingle roofs, metal roof singles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes. An exception is included for detached accessory structures not containing conditioned floor area.

  • Section R905.7.1.1 (Section R905.8.1.1 in 2009) states that in areas where the average daily temperature in January is 25°F (-4°C) or less, solid sheathing is required on that portion of the roof requiring the application of an ice barrier.
  • Section R908.3 (Section R907.3 in 2009) states that roof replacement shall include the removal of existing layers of roof coverings down to the roof deck except where the existing roof assembly includes an ice barrier membrane in which case the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane.

Retrofit: 2009, 2012, 2015, 2018, and 2021 IRC Section R102.7.1 Additions, alterations, or repairs. Additions, alterations, renovations, or repairs shall conform to the provisions of this code, without requiring the unaltered portions of the existing building to comply with the requirements of this code, unless otherwise stated.

  1. See code for additional requirements and exceptions.) Appendix J regulates the repair, renovation, alteration, and reconstruction of existing buildings and is intended to encourage their continued safe use.
  2. Access to some references may require purchase from the publisher.
  3. While we continually update our database, links may have changed since posting.

Please contact our webmaster if you find broken links. References and Resources* *For non-dated media, such as websites, the date listed is the date accessed. Contributors to this Guide The following authors and organizations contributed to the content in this Guide.

How do you repair a leaking tile roof valley?

Repairing roof valleys – If you’re going to attempt to repair roof valleys and stop leaks yourself, its best to have someone to help. Start by clearing any debris away from the valley. Roof valleys can be repaired by patching any holes or inserting a sheet of metal along the length of the valley depending on the severity of damage.

Roof valleys are an important part of your roof and not to be taken lightly. You should know that lack of maintenance or poor construction will always lead to roof valley leaks and the deterioration of more expensive parts that will ultimately cost more money to repair. For that reason, check your roof valleys regularly to ensure they are in good health.

It’s advisable to contact a professional roofing company if you are inexperienced since failing to fix roof valley leaks properly can cost you more money in the long run.

What is the difference between a hip and a valley on a roof?

What is the difference between a hip roof and a valley roof? – A hip roof has four sloping sides. A valley in a roof is where two roof surfaces connect. In a hip and valley roof, the valley is where multiple hip roofs meet.

What is it called where two roofs meet?

What are the common parts of a roof? –

Roof Ridge: The roof ridge, or ridge of a roof is the horizontal line running the length of the roof where the two roof planes meet. This intersection creates the highest point on a roof, sometimes referred to as the peak. Hip and ridge shingles are specifically designed for this part of a roof. Ridge vent: A ridge vent is an exhaust vent that runs horizontally along the peak of the roof allowing warm, humid air to escape from the attic. Use our ventilation calculator to calculate your attic ventilation requirements and determine how much exhaust ventilation you would need to properly ventilate your roof and attic. Flashing: Flashing is a metal material installed at joint openings, around chimneys, and any dormer windows or skylights to help prevent water intrusion. You may recognize flashing as metal stair steps alongside a chimney or side walls on a roof. Hip: The hip on a roof is the intersection of two roof planes that meet to form a sloping ridge running from the peak to the eave. Hip and ridge shingles are specifically designed for this part of a roof. Roof Deck: The roof deck is the structural foundation base for the roof system and is usually made of wood or plywood. Roofing Underlayment: Roofing underlayment is a layer of material, usually synthetic or felt, that adds extra protection on top of the roof deck and under the shingles. Synthetic underlayment helps repel moisture and provides protection against water infiltration. Synthetic underlayment is becoming a popular material choice over felt due to proven water-resistance performance and long-lasting durability. Roof Valley: The roof valley is the V-shaped intersection between two sloping roofs joining at an angle to provide water runoff. Laminated Architectural Shingles: Laminated architectural asphalt shingles contain more than one layer of tabs to add dimension, performance and durability to a roof. Architectural shingles are sometimes referred to as three-dimensional shingles or laminated shingles. The opposite of architectural shingles are three-tab shingles, which are produced as a single layer of tabs and appear flat or without the dimension of a laminated shingle. Roof Gable: A roof gable is the triangular section of the outer wall at the peak of the roof between a sloping roof and eave. A roof gable is sometimes referred to as a rake. Metal drip edge: Metal drip edge is a narrow strip of noncorrosive metal used at the rake and eave to help manage dripping water by facilitating water runoff to protect the underlying section of a wall. Dormer : A dormer is a raised section of the roof. Dormers commonly contain a window that projects vertically through the slope in the roof. Ice and water barrier: An ice and water barrier is a self-adhered waterproofing material installed along eaves, valleys, side walls, and other sensitive areas to protect against ice damage and wind-driven rain. Eave: An eave is the lower border of the roof that overhangs the wall usually located in the first three feet of a roof. Undereave vent: Undereave vents are intake vents located under the eaves of the roof that help draw cool dry air into the attic. Again, you can use our ventilation calculator to calculate your attic ventilation requirements and determine how much intake ventilation you would need to properly ventilate your roof and attic.

Now that you’re familiar with the basic anatomy of a roof, you’ll start to notice dormers and gables everywhere you turn. More important, you’ll be equipped to have an informed conversation with your roofing contractor when the time comes for you to get a new roof,

What is the underside of a roof overhang called?

The underside of this overhang, when given a finished appearance, is known as the soffit, which means ‘something fixed underneath’. The soffit is basically, any finishing material, such as wood or fiber cement, that is installed to cover the underside of your roof overhang.

Should 20 year old roof replace?

1. Your asphalt roof is about 20 years old – The life of a roof is how many years you get out of it. For a standard 3-tab asphalt shingle roof, that’s 25-years. As long as your roof has been properly ventilated and installed you should get pretty close to that 25 years of roof life.

  1. So obviously you want to replace your roof before it starts leaking or fails completely.
  2. A reputable roofing contractor will recommend that you replace your roof somewhere around 80-85% of the manufacturer’s life of the roof.
  3. For example, you should consider replacing a 25-year roof around the 20-year mark.
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Don’t wait until it’s too late, get ahead of any potential problems and replace your roof before the end of its life.

What time of year is best to replace a roof?

Fall – Fall is the universal go-to season for roof replacement. With spring’s mild temperatures and early summer’s weather consistency, fall is commonly referred to as the best time of year to replace your roof. Since this season is highly sought after, finding appointment times in the fall can become tedious, so it is best to plan ahead in order to beat the rush.

How does water get under shingles?

Roof Leak – Ten Most Common Leak Locations A roof leak is a major nuisance for most homeowners. Finding a leak can be frustrating or relatively simple, depending on location and weather conditions. Leak detection may go easier with these tips for locating a water leak and roof leak repair.

  • Roof One LLC, a Michigan Roof Contractor, is ready to assist you with a FREE Roof Estimate, Storm Damage Analysis, and/or preventive maintenance inspection, at your request Roof leaks are a nuisance for many homeowners.
  • They can be difficult to diagnose – that is a fact.
  • To make matters worse, different weather conditions will produce leaks in different locations.

The vast majority of roof coverings operate using the principal of gravity. This can be a big help in locating a leak source. However, horizontal roof boards can trick you. A leak may actually be eight to 10 feet sideways from where you see the wet ceiling or spot in the attic.

Finding the source of some leaks is easy. Others will require detective work and possibly a garden hose and an inside spotter. If you don’t feel comfortable on a roof, call Roof One LLC to do a free roof damage analysis for you. Sometimes this can be as hard as finding the smallest leak! Here are some tips that may help you find a pesky roof leak If your roof is older, it is possible that the leak is within the roof field.

This means the expanse of shingles, slate, shakes, whatever. If your roof is asphalt, then you can walk around with ease. Other materials such as slate, concrete tile or clay tile may not be so forgiving. You can crack roofing if you walk on it, so be careful.

  1. With regular shingles, look at the tops of the vertical knockouts.
  2. Look for missing colored granules.
  3. Look for cracks.
  4. Possibly a nail has backed itself out of the roof sheathing.
  5. Simply take your time and hunt.
  6. A valley is a line where two roof planes intersect.
  7. Here in Cincinnati we use a metal flashing in the valleys.

Some areas use rolled roofing. Other places simply lace the shingles together. Valleys can be big problems if you do not trim the shingles correctly. When you trim a shingle for a valley you end up with a chisel point on the end of the shingle. If a second cut is not made to make this point like an arrow point, then water can travel along the top of the shingle and find its way inside your house.

  • The shingle wrapper tells you how to make this simple second cut.
  • Some roofs stop at a vertical wall.
  • A metal flashing must be in place to direct water streaming down the wall away from the stopping point of the shingles.
  • This flashing may be behind wood siding or in front of a brick wall.
  • The flashing should extend over the shingles at least three inches.

If the wall is brick or other masonry, the flashing must bend and extend one inch into a mortar joint. Tar, caulk or roofing cement should never be used in conjunction with these materials. If you see them, it is a sign that someone tried to patch a leak! Some roof leaks happen at step flashings.

  1. You find these flashings where a roof climbs alongside a vertical wall.
  2. As each row of shingles is laid, a step flashing is installed over the shingle next to the wall.
  3. Part of the flashing turns up on the wall and the other portion gets covered by the next row of shingles.
  4. Look for rust or holes in these flashings.

In reality, if all is well, you will be able to see only the smallest portion of these flashings. These devils are the source of many a leak. Chimneys contain four different types of flashing. All must be right or you will have a leak. Plus, the counterflashing that goes into the brick mortar joint must be right.

  • A hairline crack above the flashing can allow vast amounts of water to run behind the flashings.
  • Look for soldered corners of flashing that might have broken or have holes.
  • Do not use caulk to repair these flashings! Newer vent flashings are a concern of mine.
  • Many of these incorporate a rubber seal with an aluminum flashing.

The rubber can fail in as little as 10 to 15 years. Look for cracked rubber around the plumbing pipe. The flashing should dive up and under the shingles that extend up roof from the middle of the plumbing vent. The bottom half of the flashing should be exposed and actually cover the shingles.

These flashings are basically identical to plumbing vent flashings. However, they sometimes have a metal storm collar. These simply fit tightly around the vertical pipe that exits the roof. If they become loose, the storm collars can cause leaks. Ice dam leaks plague people in the snow belt. These leaks can happen even if everything on your roof is just fine! Ice dams block the natural flow of water down a roof.

The water begins to back up under flashings, shingles, tar paper, etc. Once water begins to flow into the house, it can drip for days. The only means of prevention is to install membranes under the roofing. The membranes won’t stop the ice but will stop water leaks if installed properly.

Wind driven rain can also be a major problem. Once again, you could actually have a good roof and wind will drive water up and under your roofing materials. The only lines of defense are tar paper and the ice dam membranes.If you have metal valleys, you may want to hem the edges. This means that the hidden edges of the valley actual have a 180 degree bend.

This creates a channel that directs wind blown rain back to the bottom of the valley.Roofing cement under shingles on the edges of roofs that face the wind are also a good idea. Don’t underestimate the power of a 70 mph sustained wind-driven rain. Sometimes you think you have a roof leak when in fact the roof is fine.

Attic condensation is a prime example. High humidity can cause condensation and “rain” to fall in your attic. It can also make the underside of the roof sheathing look wet. You think you have a leak instead.Chimney crowns can develop cracks. The inside surface of the chimney gets discolored or the plaster bubbles.

You think a roof leak is the cause.Siding can be missing above a roof. This can cause water to enter behind head flashings. Be a good gumshoe and snoop around for the leaks! : Roof Leak – Ten Most Common Leak Locations

How do you waterproof a valley?

Scope Install a self-sealing membrane in roof valleys and around penetrations to minimize the possibility of roof leaks.

  • Choose a self-sealing membrane such as a bituminous peel-and-stick material or equivalent at all valleys and roof deck penetrations.
  • In valleys, install this layer directly on the roof sheathing surface beneath the roofing felt.
  • Around penetrations such as pipes or vents, install one piece to surround the pipe from the down-slope side of the pipe, then install the upslope piece to overlap the upper edge of the down-slope side. Integrate with the roofing underlayment.
  • Building code requirements for roof valley flashing vary by roofing material type.

See the Compliance Tab for related codes and standards requirements, and criteria to meet national programs such as DOE’s Zero Energy Ready Home program, ENERGY STAR Certified Homes, and EPA Indoor airPLUS, Description The roof is the house’s primary defense against water intrusion from rain, snow, and ice.

This “lid” of the home must be structurally sound and must be designed and constructed to shed water effectively and consistently through all seasons, extreme weather events, and atmospheric conditions. Water that leaks into the house through the roof can quickly damage insulation, create conditions for mold growth and pest invasion, and even set into motion structural rot.

Over time even the smallest leak in a roof can result in a significant amount of water damage, and not just in the attic. Once inside the home, water can travel laterally as well as vertically along framing members to cause damage in ceilings, walls, floors, and even basements.

Valleys and penetrations through the roof decking are among the most vulnerable areas for water intrusion. Valleys should be carefully sealed along the entire length. To help prevent water entry at these vulnerable points, install a self-sealing bituminous membrane or the equivalent along all valleys and properly integrate this membrane into the adjoining roofing materials.

Self-sealing membrane should also be installed, along with flashing, around all penetrations through the roof including direct penetrations like plumbing stack vents and structural penetrations like dormer windows and chimneys. Sheathing seams should be sealed with a compatible tape.

  1. Most roofing membranes are made of a heavy, flexible bituminous material that has been impregnated with a petroleum-based solution like tar which makes the material waterproof.
  2. Most membrane products come with a “peel and stick” adhesive backing.
  3. When properly installed these products provide long-lasting protection from water intrusion.

Note: The U.S. Environmental Protection Agency (EPA) uses the phrase “or equivalent” to indicate that a variety of products can be used. Regardless of the product’s composition, it must be water impermeable and must durably adhere to the roof deck. Please check with the manufacturer’s material classifications and installation instructions to ensure the material you choose will adequately protect the roof from water intrusion ( EPA 2011 ).

Building codes generally do not require a sealed roof deck for new homes or roof replacements, but a sealed roof deck is beneficial in any area and is particularly recommended in hurricane-prone or high-snow-load regions. Sealed roof deck valleys and sealed penetrations are components of a sealed roof deck.

Note: The U.S. Environmental Protection Agency (EPA) uses the phrase “or equivalent” to indicate that a variety of products can be used. Regardless of the product’s composition, it must be water impermeable and must durably adhere to the roof deck. Please check with the manufacturer’s material classifications and installation instructions to ensure the material you choose will adequately protect the roof from water intrusion. Figure 1. Peel and stick membrane applied to roof valley. These workers are properly installing a self-sealing bituminous membrane to a valley on the roof deck. Note the material is centered along the valley to ensure maximum protection. (Source: EPA Indoor airPLUS, 2020.) How to Install Self-Sealing Bituminous Membranes along Valleys of Roof Decks

  1. Clean the roof deck sheathing along the valley to ensure it is free of loose nails, wires, and debris. Although the membrane is made from relatively strong material, it can be torn or punctured. Make sure the area is dry and free of oil and dust to ensure the membrane will adhere properly.
  2. Measure the length of the valley to be covered.
  3. Cut the self-sealing bituminous membrane to length. For extremely long valleys, cut the material in shorter, more manageable lengths.
  4. Install metal drip if required or desired for wild fire and hurricane resistance. Install self-adhering bituminous membrane along roof eave as required by code or desired to reduce risk of water damage from ice dams.
  5. Install the membrane directly on the roof sheathing material (typically OSB). Apply from the lowest point to the highest, overlapping membrane sections by 6 inches in shingle fashion to allow water to flow unobstructed down the length of the valley. The membrane must be straight and centered with the valley line. Installation note : Some peel-and-stick membrane products come with a lengthwise split along the protective backing that can give you a guideline for centering the product while you peel and install it along first one side of the valley then the other.
  6. Make sure the membrane lays flat with no gaps, creases, or folds. Secure the material in place with a heavy roller.
  7. Install the membrane and continue with installation of the roof cladding. (See Figure 2. Fasteners should not be located within 6 inches of the valley center.)
  8. If installing a shingle roof cladding, metal valleys are recommended over woven or abutted shingle cladding in valleys.

Figure 2. Use bituminous seal-sealing membrane to seal roof valleys. The self-adhesive membrane is installed directly on the plywood roof deck beneath the underlayment (roofing felt) and shingles. (Source: EPA Indoor airPLUS, 2020.) How to Install Self-Sealing Bituminous Membranes around Direct Penetrations in the Roof

  1. Clean the roofing area after the pipe or vent has been installed through the roofing deck. Make sure roof deck around the penetration is free of loose nails, wires, debris, dust, oil, or water.
  2. Starting at the eave side of the roof below the penetration, install the underlayment (roofing felt) up to the penetration.
  3. Measure the area to be covered and cut a piece of membrane to fit around the lower half of the penetration, allowing for at least 6 inches of membrane on each side and below the penetration. See Figure 3.
  4. Install the self-adhesive membrane so that it seals tight around the pipe and laps over the roofing felt, as shown in Figure 3. Use a heavy hand roller to secure in place. Some manufacturers require that a primer be applied before the membrane is installed, particularly during cold weather or damp conditions.
  5. Measure and cut a piece of membrane to fit around the upper side of the pipe. A flexible-type membrane like flashing tape is ideal for flashing around pipes. Install so that it seals tightly around the pipe and the edges overlap the top edge of the first piece of membrane, as shown in Figure 3.
  6. Continue installing underlayment above the penetration to overlap this membrane.
  7. Install shingles or roofing material up to the penetration.
  8. Install a pre-manufactured pipe flashing over the pipe and shingles, as shown in Figure 4 and Figure 5.
  9. Continue installing shingles above the pipe to cover the top edge of the flashing.
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Figure 3. Seal around piping and other roof penetrations with self-sealing bituminous membrane that is layered shingle-fashion with the roof underlayment. (Source: EPA Indoor airPLUS, 2020.) Figure 4. Install a pre-manufactured pipe flashing cap around the pipe and integrate installation so that the upper edge of the flashing is covered by rows of asphalt shingles above the piping. (Source: EPA Indoor airPLUS, 2020.) Figure 5. Integrate pre-formed vent pipe flashing, shingle-fashion, with roofing underlayment and shingles. (Source: Home Innovation Research Labs, 2020.) How to Seal around Structural Penetrations and Roof-Wall Junctures

  1. Clean the roofing area after the dormer or other structure has been installed through the roofing deck. Make sure the roof deck around the structure is free of loose nails, wires, debris, dust, oil, or water.
  2. Install underlayment to lap up the vertical wall at least 8 inches and secure in place. Alternatively, install the underlayment to the vertical wall and install self-adhesive membrane over the underlayment and up the wall at least 8 inches.
  3. Install the step flashing and kick-out flashing and secure in place.
  4. Apply self-adhesive membrane material directly over the vertical rise of the step flashing and up the side of the penetration.
  5. Install the WRB material over the peel and stick, securing it in place and attaching it to the membrane with tape.
  6. Continue installing the roofing material.
  7. Alternately, the self-adhering membrane can be installed prior to the step flashing as described in the guide Step and Kick-Out Flashing at Roof-Wall Intersections, Apply to the roof deck and lap up side wall, install metal step flashing, cover top of metal flashing with self adhesive tape flashing, install house wrap and siding over tape flashing.

Figure 6. Protect roof-wall intersections, as required for structural roof penetrations such as dormers or a framed chimney, with step flashing and self-adhesive bituminous membrane. Ensuring Success To ensure that the roof valleys and penetrations are well sealed, the area must be cleaned prior to installation of the self-adhesive bituminous membrane.

Only a complete seal will help keep water from finding a way through the valley and entering the house. Also, once applied, the membrane must be rolled flat so that no folds or creases are present. Climate Hurricane-Prone Regions Roofing and wall cladding are more likely to be damaged or lost in hurricane-prone regions and other high-wind areas, leaving flashing and underlayment exposed and more susceptible to wind and water intrusion.

Proper installation of flashing and sealing products is even more important in these areas to protect against storm damage. The IRC does not have additional requirements for roof-wall flashing in hurricane-prone regions or other high-wind areas. Some local jurisdictions may have additional requirements or require specific product approval.

Building codes establish minimum requirements, but products must also be installed in accordance with manufacturer’s instructions. This is important because codes typically do not provide all the detailed information for a durable installation. Assessments by FEMA after hurricanes commonly find that water intrusion and structural building failures are due to improper installation of building components.

So, even where the IRC does not require additional measures, proper installation is more critical in hurricane-prone regions. The Insurance Institute for Business and Home Safety ® (IBHS) offers guidance, best practices, and voluntary construction standards and programs for building in disaster-prone areas including hurricane and other high-wind zones.

  • The IBHS FORTIFIED Roof program includes options for sealed roof decks.
  • IBHS also provides specific guidance for flashing including roof valley flashing.
  • Sealing the roof deck at valleys and penetrations and proper sealing of the roof deck using self-adhesive membrane and underlayment can significantly prevent water infiltration through the roofs during hurricanes when the primary roofing is damaged.

See the Hurricane Technical Summary for New Construction by the IBHS Fortified Home program for all of the methods that can be adopted for sealing roof decks. High Snow Load Regions In areas with deep or sustained snow cover (Figure 1), extra protection of roof valleys as shown in this guide, is recommended. Figure 1. Design Snow Loads Map for the United States, adapted from ASCE 7-10, Figure 7-1 (Source: Medeek Design 2015 ). The Compliance tab contains both program and code information. Code language is excerpted and summarized below. For exact code language, refer to the applicable code, which may require purchase from the publisher.

  1. While we continually update our database, links may have changed since posting.
  2. Please contact our webmaster if you find broken links.
  3. ENERGY STAR Certified Homes, Version 3/3.1 (Rev.09) Water Management System Builder Requirements 3.
  4. Water-Managed Roof Assembly.3.3 Self-adhering polymer-modified bituminous membrane at all valleys & roof deck penetrations.3, 16 Footnote 4) Not required in Dry (B) climates as shown in 2009 IECC Figure 301.1 and Table 301.1.

Footnote 15) As an alternative, any applicable option in 2009 IRC Section R905.2.8.2 is permitted to be used to meet Item 3.3 and any option in 2009 IRC Section R905.2.7.1 is permitted to be used to meet Item 3.4. EPA recommends, but does not require, that products meet ASTM D1970.

In addition, any option in 2009 IRC Section R905.13 is permitted to be used to meet either Item 3.3 or 3.4. Please see the ENERGY STAR Certified Homes Implementation Timeline for the program version and revision currently applicable in your state. DOE Zero Energy Ready Home (Revision 07) Exhibit 1 Mandatory Requirements.

Exhibit 1, Item 1) Certified under the ENERGY STAR Qualified Homes Program or the ENERGY STAR Multifamily New Construction Program.2009, 2012, 2015, 2018, and 2021 International Residential Code (IRC) Section R905.3.8 Flashing. Flashing and counterflashing to be provided at the juncture of roof vertical surfaces per manufacturer’s instructions.

If metal, it cannot be less than 0.019 inch (No.26 galvanized sheet gage) corrosion-resistant metal. Valley flashing must extend at least 11 inches from the centerline each way and have a splash diverter rib not less than 1 inch high at the flow line formed as part of the flashing. Sections of flashing must have an end flap at least 4 inches.

For 3/12 roofs and greater, valley flashing must have a 3-ft wide underlayment of one layer of Type I underlayment running the full length of the valley, in addition to any other required underlayment. Metal valley flashing underlayment must be solid-cemented to the roofing underlayment for slopes less than 7/12 or be self-adhering polymer modified bitumen sheet in areas where the average daily temperature in January is 25°F.

Section R905.2.8.2 Valleys – For asphalt roofs, open valleys (valley lining exposed) should be lined with a strip of corrosion-resistant metal (listed in Table R905.2.8.2) that is at least 24 inches wide or two layers of mineral–surfaced roll roofing with the bottom layer strip at least 18 inches wide and the top layer at least 36 inches wide.

For closed valleys (where the valley is covered with shingles) the valley should be lined as described for open valleys or with one ply of smooth roll roofing at least 36 inches wide or with self-adhering polymer modified bitumen complying with ASTM D1970.

Requirements vary for other roofing types. See Section R905.4.6 for metal roof valley flashing requirements, Section R 905.6.6 for slate roof valley flashing, Section R 905.7.6 for wood shingle roof valley flashing, and Section R 905.8.8 for wood shake roof valley flashing. Section R905.1.2 (Section R905.2.7.1 in 2012 and 2009) specifies ice barrier requirements for geographic areas where there has been a history of ice dams.

Requirements apply to asphalt shingle roofs, metal roof singles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes. An exception is included for detached accessory structures not containing conditioned floor area.

Section R905.7.1.1 (Section R905.8.1.1 in 2009) states that in areas where the average daily temperature in January is 25°F (-4°C) or less, solid sheathing is required on that portion of the roof requiring the application of an ice barrier. Section R908.3 (Section R907.3 in 2009) states that roof replacement shall include the removal of existing layers of roof coverings down to the roof deck except where the existing roof assembly includes an ice barrier membrane in which case the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane.

Retrofit: 2009, 2012, 2015, 2018, and 2021 IRC Section R102.7.1 Additions, alterations, or repairs. Additions, alterations, renovations, or repairs shall conform to the provisions of this code, without requiring the unaltered portions of the existing building to comply with the requirements of this code, unless otherwise stated.

  • See code for additional requirements and exceptions.) Appendix J regulates the repair, renovation, alteration, and reconstruction of existing buildings and is intended to encourage their continued safe use.
  • Access to some references may require purchase from the publisher.
  • While we continually update our database, links may have changed since posting.

Please contact our webmaster if you find broken links. References and Resources* *For non-dated media, such as websites, the date listed is the date accessed. Contributors to this Guide The following authors and organizations contributed to the content in this Guide.

How do you seal a valley?

Metal flashing allow water to flow down the valley – Open valleys have the flashing exposed and the shingles end at the flashing edges. To seal make sure there is no debris in the valley. Check that the roofing material is cut in a straight smooth line on each side.

  1. The distance between the shingles should widen from the ridge to the eave at 1/8 inch per foot of valley.
  2. Lift each shingle and use roofing cement to coat the area that lies on the valley.
  3. Use a cartridge gun to run a bead of roofing cement down the valley next to the shingles.
  4. If you need to patch a valley flashing cut a piece of sheet metal the same gauge as the original flashing.

Cut a patch larger than the damaged area and wide enough to slide under the shingles. Apply a bead of roofing cement around the outer edge of the patch slide the patch under the shingles on one side and then the other. Put more roofing cement on the top and bottom of the patch where it lays over the original valley piece.

Smooth the cement so water can flow uninterrupted down the valley. You can also check online for video tutorials on how to repair your flashing. As always be careful if you go up on your roof to do any repairs yourself. If you are in doubt, hire your to make the repairs for you. Get a free quote from a roof contractor in your neighborhood in seconds! We never share your information and only seek to put you in touch with the best local roofer in your area.

: Sealing Valleys on a Roof

How do you repair a leaking tile roof Valley?

Repairing roof valleys – If you’re going to attempt to repair roof valleys and stop leaks yourself, its best to have someone to help. Start by clearing any debris away from the valley. Roof valleys can be repaired by patching any holes or inserting a sheet of metal along the length of the valley depending on the severity of damage.

Roof valleys are an important part of your roof and not to be taken lightly. You should know that lack of maintenance or poor construction will always lead to roof valley leaks and the deterioration of more expensive parts that will ultimately cost more money to repair. For that reason, check your roof valleys regularly to ensure they are in good health.

It’s advisable to contact a professional roofing company if you are inexperienced since failing to fix roof valley leaks properly can cost you more money in the long run.

How do you seal a metal roof Valley?

How to Seal Metal Roof Valley – Best practices for sealing the metal roof valley vary based on the slope of the roof. Low Slope Roofs (Slope less than 3:12) Use tape sealant between the valley trim and the panel. Use fasteners to attach the panel to the structure, making sure that there is complete compression of the sealant.

  1. Steep Slope Roofs (Slope greater than 3:12) Cut the panels at an angle for the valley, then bend the hem end of the panel and hook it with a cleat.
  2. This approach is ideal for architectural applications because the fasteners are hidden.
  3. Watch the short video or read the information below to learn more how to install valley trim: Here you have your eave trim with the continuous cleat hiding it all, but we have a valley, so, we’re ready to put valley trim because this will change the sequence of events for what goes on here.

We have two roof planes here that meet in this valley, and ordinarily on a straight eave we would install the tape seal and the offset cleat right away. In this case, because the sequence of events changes and we need to overlap properly, the valley’s going to be installed.