9 Dec 2022 ... Does your roof look like this? It could be missing ice and water shield like Kurt describes in the video. #JoylandRoofing #iceandwatershield ...As for ice shield, yeah maybe slightly over rated, but very cheap insurance and it does offer an increased level of protection. We won't install a sloped roof without ice shield at the gutter lines, valleys and pre-flashings at any area to later receive metal including chimneys, pipes, vents, and where the roof meets the walls.TABLE R905.1.1(1) UNDERLAYMENT TYPES ROOF COVERING: SECTION: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult < 140 MPH: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult ≥ 140 MPH: Asphalt shingles: R905.2: ASTM D226 Type I ASTM D4869 Type I, II, III or IV ASTM D6757: ASTM D226 Type II ASTM D4869 Type IV …That said, on average, most contractors will charge between $4.50 and $8.00 per square foot or $450 to $800 per square (100 sq.ft.) to install or replace an asphalt shingle roof on a typical house. On average across the US, it will cost between $9,000 and $17,600 to replace a 2,000-2,200 sq. ft. roof on a single-family house up to two-stories high.The ice and water shield calculator works by first determining the total surface area of your roof, which is obtained by multiplying the length and width of the roof. It then divides this total area by the coverage rate per roll specified by the manufacturer. Lastly, it adds extra material for overlaps and waste during installation.GRACE ICE and WATER SHIELD self-adhered roofing underlayment is a premier membrane composed of 2 waterproofing materials-an aggressive rubberized asphalt adhesive backed by a layer of slip resistant coated high density cross laminated polyethylene film. The rubberized asphalt surface is backed with a foldless release paper …In today’s fast-paced world, it’s essential to have access to convenient and efficient healthcare services. Blue Shield understands this need and has developed a user-friendly onli... R909.3 Installation. Rooftop-mounted photovoltaic systems shall be installed in accordance with the manufacturer's instructions. Roof penetrations shall be flashed and sealed in accordance with this chapter. UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction. GRACE ICE & WATER SHIELD® protects a homeowner's roof from the damaging effects of water intrusion due to wind-driven rain and ice dams because it: Fully adhered roofing underlayment sticks aggressively to deck surface. Forms a watertight seal around fasteners used to install shingles and other roof coverings. Forms watertight seal at overlaps. 2 June 2021 ... Building Waterproof Membrane Water and Ice Shield Synthetic Roofing Underlayment ASTM Cetificate UV Resistance Roof Felt Custom Logo Printed ...Ice and water shield is used as an underlayment for roofs. It allows you to easily cover your roof and insulate it from ice, water, and snow damage. If you live in colder climates, protecting your roof from everlasting snow and melting ice is essential. Ice can slowly damage your roof, causing seepage and slow growth of mold and other water ...The Canadian Shield was formed by a combination of plate tectonics, volcanic eruptions, sedimentary deposits and erosion. It was the first part of North America to be permanently a...Getting a new roof costs thousands of dollars. For this reason, it’s important to do what you can to make it last as long as possible. You can possibly do some of these things your...Ice and water shield in the valley should go over the ice and water shield on the eave. The shingles should not be reused because you are paying for a new roof not a repaired new roof. 6 feet on the eave and valley is a substantial area of the roof. Lot numbers of the new shingles may have a noticeable although slight variation in color.30 Mar 2022 ... The definition of ice and water shielding is simple: It's a layer of peel and stick underlayment that you put in place to protect a roof deck ...It creates a watertight seal around roofing nails and can even protect the roof if shingles are blown off. The shield should extend to the eaves, edges, and ... Roofing materials that do require an ice barrier are: “asphalt shingles, metal roof shingles, mineral surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes.”. Though not called out in R905.1.2, PV roof shingles and building-integrated PV roof panels do require an ice barrier, and that is noted under the ... Exceptions: As an alternative, self-adhering polymer-modified bitumen underlayment complying with ASTM D1970 installed in accordance with both the underlayment manufacturer's and roof covering manufacturer's instructions for the deck material, roof ventilation configuration and climate exposure for the roof covering to be installed, shall …TABLE R905.1.1(1) UNDERLAYMENT TYPES ROOF COVERING: SECTION: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult < 140 MPH: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult ≥ 140 MPH: Asphalt shingles: R905.2: ASTM D226 Type I ASTM D4869 Type I, II, III or IV ASTM D6757: ASTM D226 Type II ASTM D4869 Type IV …A 6.5-7" of 2lb roofing polyiso (blown with low impact pentane) would hit an IRC code-max U0.026 U-factor even though it's only R38- R40, and would be BETTER at reducing ice dam potential than R49 between purlins. Laying 2x4 purlins atop the rigid roofing foam through-screwed to the rafters takes some pretty long screws.Water dam – Ice and water shields are designed to help divert the flow of water that falls from your roof away from certain areas. This helps keep it flowing smoothly off your roof, which can prevent damage caused by excess moisture. Wind driven rain – The reflective underside of the ice and water shield also works as a windbreaker. The …27 Oct 2022 ... If peace of mind is what you are looking for out of your roofing project, then look no farther than GCP's Grace Ice & Water Shield®. Grace Ice & .....The Best Ways To Get Rid of Ice Dams. You can temporarily get rid of ice dams by melting them away. There are four safe ways your roofing professional can remove an ice dam from your roof: Use hot water: Running hot water over the ice dam, gently, will melt it and allow the water to drain out through the gutters.IWS is used in conjunction with step flashing or 4x5 wall flashing to create a water tight junction. In this video Isaac illustrates installation of an 18" w...TABLE R905.1.1(1) UNDERLAYMENT TYPES ROOF COVERING: SECTION: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult < 140 MPH: MAXIMUM ULTIMATE DESIGN WIND SPEED, V ult ≥ 140 MPH: Asphalt shingles: R905.2: ASTM D226 Type I ASTM D4869 Type I, II, III or IV ASTM D6757: ASTM D226 Type II ASTM D4869 Type IV …WeatherWatch® Mineral-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System.1 It’s eligible for Lifetime limited warranty when used on Lifetime Shingle roofs1 and it’s an ... Ice and Water Shield. Water Resistant. High Wind Resistant, Water Resistant. Water Resistant. Application Method. Nail, Peel & Stick. Nail. Peel ...S-5! clamps attach virtually anything to standing seam metal roof profiles with zero penetration. Our innovative round-point setscrews offer a secure mechanical interlock while protecting the standing seam and its sacrificial coating, leaving roof warranties intact. All clamps and snow retention systems are designed to outlast the roof using ...Your roof valleys are crucial to keeping water flowing in the right direction down your roof. Because of this, they need something to protect them from the constant flow of water every time it rains. Ice and water shield is the waterproof membrane used to protect your roof from ice and water damage. In this video, we break down what you …GRACE ICE & WATER SHIELD® HT is a version of the flagship product that is formulated to be more thermally stable and ideal for use under metal roofing or in high-temperature roofing assemblies. GRACE SELECT™ is a code-compliant performance alternative to granular underlayments. Its lower thickness makes it lighter and easier to apply than ...Ice and water shields are designed to provide a watertight barrier on a roof to prevent water infiltration in areas prone to ice dams, heavy rain, or other sources of water …Ice and water shield is technically an underlayment designed to be installed underneath a shingle, tile, or metal roof. Normally, this would be a felt underlayment commonly known as tar paper or roofing felt. Ice and water shield takes the idea of underlayment a step further. Whereas standard underlayment … See moreIce and water shields are designed to provide a watertight barrier on a roof to prevent water infiltration in areas prone to ice dams, heavy rain, or other sources of water …The price of synthetic roof underlayment will vary depending on the lifespan of the product and whether it’s non adhesive or self adhesive. 25 year non adhesive underlayment = $.15 to $.20 Per square foot. 50 year non adhesive underlayment = $.20 to $.25 Per square foot. 50 year self adhesive underlayment = $.55 to $.65 Per square foot.What is Ice and Water Shield exactly? Ice and Water Shield is still a fairly new product in the roofing industry, but boy, it's made a huge impact on our ab...Blue Cross Blue Shield insurance is available to most people in the USA, so it makes sense to consider this provider’s plans as you shop for healthcare coverage. This guide will he...WeatherWatch® Mineral-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System.1 It’s eligible for Lifetime limited warranty when used on Lifetime Shingle roofs1 and it’s an ... Ice and Water Shield. Water Resistant. High Wind Resistant, Water Resistant. Water Resistant. Application Method. Nail, Peel & Stick. Nail. Peel ...The big question is, "Do I install the ice and water shield over or under the felt or synthetic underlayment?" The next question, "Should I install the IWS o...There is a large variety of wildlife in the Canadian Shield, also called the Boreal Shield, including waterfowl, land animals, mammals and fish. According to the Ecological Framewo...However, as a general guideline, the cost of Ice and Water Shield can range from $0.50 to $2.00 per square foot. Lower-end products may be available at around $0.50 to $1.00 per square foot, while higher-quality options or specialty products may cost around $1.50 to $2.00 per square foot or more.An SBS modified bitumen roofing membrane underlayment. Henry ® Blueskin ® RF200 is a self-adhered rubberized waterproof roofing membrane underlayment for use on sloped roof surfaces as a secondary seal under shingles, cedar shakes, and some architectural metal and tiles. It's an SBS-modified bitumen roofing membrane underlayment …Grace Ice & Water Shield® has been the premier self-adhesive underlayment product used in domestic roof protection under shingles for more than 20 years. It has ...Clean and dry the roof surface: Before installing the ice and water shield, make sure the roof surface is clean and dry. Remove any debris or loose material that may interfere with the adhesion of the shield. Overlap the sheets: When installing multiple sheets of ice and water shield, make sure to overlap them properly. In areas where there has been a history of ice forming along the eaves causing a backup of water as designated in Table R301.2(1), an ice barrier shall be installed for asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes. What is Ice and Water Shield exactly? Ice and Water Shield is still a fairly new product in the roofing industry, but boy, it's made a huge impact on our ab...That said, on average, most contractors will charge between $4.50 and $8.00 per square foot or $450 to $800 per square (100 sq.ft.) to install or replace an asphalt shingle roof on a typical house. On average across the US, it will cost between $9,000 and $17,600 to replace a 2,000-2,200 sq. ft. roof on a single-family house up to two-stories high.18 Apr 2017 ... It is not absolutely necessary but it is extra protection over that area of the roof that could potentially have water backing up from roof edge ...When it comes to transporting your snowmobile, investing in a high-quality trailer salt shield is essential. A salt shield not only protects your snowmobile from road debris and ha...The roof needs to be repaired if it is damming. Poor insulation and air leaks are a typical cause. Improving attic ventilation can be a stopgap. For low slope roofs, ditching the shingle for a flat roof membrane system is ideal. Even with water&ice shield under the shingles, a roof that is ice damming will leak. –An ice and water shield, also known as a roofing underlayment, is a waterproof, rubberized underlay installed underneath … Shop Grace Ice & Water Shield 36-in x 75-ft 200-sq ft Rubber Roof Underlayment in the Roofing Underlayment department at Lowe's.com. The original, best-in-class self-adhered roofing underlayment. Photo Credit: Owens Corning. An ice and water shield, also known as an ice and water barrier, is a crucial component of roofing systems in regions prone to ice dams and heavy snowfall. It is a self-adhesive, rubberized asphalt membrane installed on the roof deck, typically in the areas most vulnerable to water infiltration, such as along eaves ... Mar 3, 2023 · An ice and water shield, also known as a roofing underlayment, is a waterproof, rubberized underlay installed underneath shingles. It acts as a protective barrier, protecting vulnerable areas on your roof from water damage and leaks. Ice and water shield is the waterproof membrane used to protect your roof from ice and water damage. In this video, we break down what you need to know about …13 Apr 2020 ... Ice and water shields are most needed in areas of the roof where the water is most likely to accumulate. These areas include the first 3 feet up ...Our customers remain at the forefront of our priorities, influencing every facet of our operations. TopShield® stands as an exclusive label offering superior residential and commercial building products, along with siding accessories. These offerings are meticulously tailored to meet the exacting standards of professional contractors ...9.26.5.1. Required Eave Protection. (1) Except as provided in Sentence (2), eave protection shall be provided on shingle, shake or tile roofs, extending from the edge of the roof a minimum of 900 mm up the roof slope to a line not less than 300 mm inside the inner face of the exterior wall. (2) Eave protection is not required, (a) over unheated ...When installing ice and water shields, it is essential to follow the proper procedure to ensure maximum effectiveness. First, the surface must be cleaned thoroughly, removing any debris or dirt that could compromise adhesion. The shield should then be applied directly onto the roof deck, starting at the eaves and working upwards. Generally, Ice and Water Shield does not need to be applied to the whole roof. For a steep roof (over 4:12) you could apply it to the entire roof, but it’s probably overkill and an added expense. For a low slope roof with shingles (4:12 or less), it’s an option to meet the underlayment requirements dictated by the IRC. Ice and water shield is a self-adhering waterproofing underlayment that is used in roofing to help prevent damage caused by ice dams and wind driven rain. The following are 3 common uses for ice and water shield in the roofing industry. 1. Eaves and rakes – Ice and water shield is used on eaves to help protect the decking and interior of …5 Dec 2010 ... http://go.askthebuilder.com/NewsletterSignupNow founder, Tim Carter shows what ice and water shield is on a new roof.Jan 10, 2024 · The 120 V constant-wattage (5 watts per linear foot) heating cables will prevent damage to your roof and gutters all winter long. These kits include everything you’ll need for an easy and safe installation. Features: · Includes: heating cable, clips, and spacers. · DIY-friendly with plug-in operation (no additional controls required) 22 Feb 2020 ... If the roof is not properly ventilated, the Ice & Water Shield will trap more moisture then normal causing the potential for mold growth and ...The roof needs to be repaired if it is damming. Poor insulation and air leaks are a typical cause. Improving attic ventilation can be a stopgap. For low slope roofs, ditching the shingle for a flat roof membrane system is ideal. Even with water&ice shield under the shingles, a roof that is ice damming will leak. –In today’s fast-paced world, it’s essential to have access to convenient and efficient healthcare services. Blue Shield understands this need and has developed a user-friendly onli...Normally, other materials that are exposed to water and ice tend to slip-off from rooftops. By covering an entire roof with ice and water protectors, roofs are ...The ice and water shield works by sealing around nails, fasteners, and other penetration points, preventing water from seeping through and causing damage. Its self-adhesive nature allows it to bond directly to the roof deck, ensuring a continuous, watertight seal. In cold climates, it is particularly effective at preventing damage caused by ice ...Liberty_Roofing_and_ May 31, 2008, 1:40am 5 IMO you eithier scrape it off as good as you can and go over it with new, or you remove the decking and install new.In today’s digital age, managing your health insurance has never been easier. With the advent of online platforms, such as My Blue Shield Account, individuals can access their heal...To design a family shield, decide on a background shape, add artwork relating to aspects of your family heritage, choose colors that appeal to you and your family history, and add ...Ice and Water Shield (also known as peel and stick) has quickly become one of the most popular roofing accessories in the market today. Why? Well because it's … R909.3 Installation. Rooftop-mounted photovoltaic systems shall be installed in accordance with the manufacturer's instructions. Roof penetrations shall be flashed and sealed in accordance with this chapter. UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction. Grace Ice and Water Shield has been my go-to ice barrier roof underlayment since the mid 1980s (it was introduced in 1978) . In 2012 GCP introduced Grace ... Specifically designed to meet the challenges inherent in metal roof assemblies. Delivers all the advantages of Grace Ice and water shield® with thermal stability up to 260° F. Seals around roofing nails, resisting leakage caused by water back-up, ice dams or wind-driven rain. Can be left exposed for up to 120 days 8 Essentials for Ice and Water Shield Roof Performance. 1. Proper Installation Techniques. 2. Adequate Overlapping. 3. Protection Around Protrusions. 4. …ROOF DETAIL MEMBRANE is a premier membrane based on the GRACE ICE & WATER SHIELD® roofing underlayment technology. The new membrane has the RIPCORD® split-release on demand feature placed in the center and near the edge (18 in. width) for easy installation at the transition areas as well as allowing for future tie-ins.Ice & Water Shield. ABC Supply is a wholesale distributor of ice and water shield products, also referred to as ice and water protector. ... G.A.P. Roofing, Inc. Plus it can be applied over existing poly surface ice and water barriers so re-roofing is easy and less costly. For optimal protection, apply to entire roof deck on 2:12 to 4:12 pitch roofs. Ensure proper ventilation is met when applied over the entire roof deck. 225 sqft roll, ice & water shield, self-adhered membrane forms a watertight seal around roof fasteners, apply at eaves & in detail areas to prevent leaks caused by ice dams & on the whole roof to prevent leaks caused by wind driven rain, roll dimension: 36 in. x 75 ft. (225 sq. ft.) , upc: 048444000002.The basic cost to Install an Ice Dam Barrier is $6.11 - $7.58 per square foot in January 2024, ... Roof jacks, pneumatic roofing nailer, shingle cutting tools. Daily rental. Consumables extra. 134 square feet: $205.16: $252.18 : Unused Minimum Labor Balance of 2 hr(s) minimum labor charge that can be applied to other tasks.Also referred to as an ice and water protector, an ice and water shield is a self-adhesive waterproofing roof underlayment that acts as a shield against water and ice damage. …GRACE ICE & WATER SHIELD® HT is a version of the flagship product that is formulated to be more thermally stable and ideal for use under metal roofing or in high-temperature roofing assemblies. GRACE SELECT™ is a code-compliant performance alternative to granular underlayments. Its lower thickness makes it lighter and easier to apply than ...StormGuard® Film-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System. 2 It’s eligible for Lifetime ltd. warranty when used on Lifetime Shingle roofs 2 and it’s an eligible component of GAF residential enhanced warranties. It’s also covered by up to a 10-year ltd. warranty 3 when used with other approved non-asphaltic ...GRACE ICE and WATER SHIELD self-adhered roofing underlayment is a premier membrane composed of 2 waterproofing materials-an aggressive rubberized asphalt adhesive backed by a layer of slip resistant coated high density cross laminated polyethylene film. The rubberized asphalt surface is backed with a foldless release paper …Ice and water shield protects your roof’s integrity. The protective membrane goes on top of the roof deck and below the roofing materials. The self-adhesive …RobQuillin. 48 posts · Joined 2009. #16 · Nov 17, 2009. Ice and water has to be applied under the shingles less that a 4/12 pitch down to a 2/12 pitch. By code though at least here in Michigan it has to be applied on all roofs 2/12 pitch and up from the eave to 1 foot inside of the outer wall.Ice and Water Shield (also known as peel and stick) has quickly become one of the most popular roofing accessories in the market today. Why? Well because it's …1. Enhanced Leak Protection. Ice and water shields provide an extra layer of defense against leaks, ensuring that water does not penetrate the roof deck even if …The Canadian Shield was formed by a combination of plate tectonics, volcanic eruptions, sedimentary deposits and erosion. It was the first part of North America to be permanently a...Defender Ice & Water. Product Line: TopShield. Product Description: Roof underlay adhesive membrane consisting of a reinforced glass mat and sand ...
Ice and water shield is a waterproof, rubberized membrane that sticks to sensitive areas of your roof, reinforcing them against leaks caused by heavy storms, wind-driven rain, and ice dams. There are three main types of ice and water shield: granular surface, smooth surface, and high heat. These types are used in different applications based on .... Good online colleges
Photo Credit: Owens Corning. An ice and water shield, also known as an ice and water barrier, is a crucial component of roofing systems in regions prone to ice dams and heavy snowfall. It is a self-adhesive, rubberized asphalt membrane installed on the roof deck, typically in the areas most vulnerable to water infiltration, such as along eaves ... WeatherWatch® Mineral-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System.1 It’s eligible for Lifetime limited warranty when used on Lifetime Shingle roofs1 and it’s an ... Ice and Water Shield. Water Resistant. High Wind Resistant, Water Resistant. Water Resistant. Application Method. Nail, Peel & Stick. Nail. Peel ...If installed properly, this reliable roofing underlayment can save homeowners $18,000 in reroofing costs. Here's how… Proper installation of GRACE ICE & WATER SHIELD® The Conventional Method. Cut the membrane into 3-5 m (10-15 ft.) lengths and re-roll loosely. Peel back 300-600 mm (1-2 ft.) of release liner, align membrane.Weathertex joins the family of products composing our Weather-Tite TM Roofing system. Weathertex is a self-sealing sanded membrane for roofing eave protection, valley, hip and ridge, the perimeter of the roof and all protruding elements on the roof against ice and water infiltration. The membrane is manufactured by applying a unique elastomeric ...Get free shipping on qualified Roof Underlayments products or Buy Online Pick Up in Store today in the Building Materials Department. ... Ice and Water Shield. Waterproof. Algae Resistant. Corrosion Resistant. Extreme Heat. High Wind Resistant. Rust Resistant + View All. Product Width (in.) 7 in. 8.86 in. 18 in. 34 in. 36 in. 39.37 in. 42 in.13 Apr 2020 ... Ice and water shields are most needed in areas of the roof where the water is most likely to accumulate. These areas include the first 3 feet up ...Jun 29, 2023 · Install GRACE ICE & WATER SHIELD® roofing underlayment directly on a clean, dry, continuous structural deck. Some suitable deck materials include plywood, wood composition, metal, concrete, and gypsum sheathing. Prior to membrane application, remove dust, dirt, loose nails, and old roofing materials. Protrusions from the deck area must be removed. There is a large variety of wildlife in the Canadian Shield, also called the Boreal Shield, including waterfowl, land animals, mammals and fish. According to the Ecological Framewo...We state in our contracts that “Ice and water shield shall be installed 3 feet from all bottom edges of the roof, in all the valleys, at all pitch changes, in all flashed areas (i.e. where roof hits walls, chimney, etc.) and around all roof penetrations (i.e. skylights etc.)”Follow along with Sean as he installs ice and water shield on this modular roof for training purposes, …ROOF DETAIL MEMBRANE is a premier membrane based on the GRACE ICE & WATER SHIELD® roofing underlayment technology. The new membrane has the RIPCORD® split-release on demand feature placed in the center and near the edge (18 in. width) for easy installation at the transition areas as well as allowing for future tie-ins.In today’s digital age, managing your health insurance has never been easier. With the advent of online platforms, such as My Blue Shield Account, individuals can access their heal...Tar paper, or asphalt-saturated felt underlayment, has historically been the go-to choice for roof underlayment. However, a few challenges are associated with this type of underlayment. First, since it’s usually available in 2 or 4 square rolls, it can take many rolls to complete an average-sized roof.An ice and water shield is a thin, waterproof membrane designed to protect your roof from ice and water damage. Without proper protection, your roof becomes susceptible to water and ice damage, leading to rotting and mold.You'll love the Grace Ice & Water Shield HT Roofing Underlayment - 36" x 66.6' Roll at DIY Home Center - Shop Great Deals on All Building Products.Ice and water shield protects your roof’s integrity. The protective membrane goes on top of the roof deck and below the roofing materials. The self-adhesive …The 3 types of ice and water shield. There are 3 types of ice and water shield: granular/sand …While this practice is less problematic with a vented roof, which can dry into the vent cavity, it still suffocates the wooden roof deck and relies on the principle of the "perfect" seal, which works only as long as it remains perfect. If it fails for any reason, then it becomes a moisture trap. #2.Dec 20, 2021 · An ice shield, sometimes known as an ice shield, is a rubberized membrane that clings to and adheres to your roof deck. An ice and water shield sticks to the roof sheathing, providing waterproofing, and protecting your roof much more effectively due to its self-adhesive feature. When installing ice and water shields, it is essential to follow the proper procedure to ensure maximum effectiveness. First, the surface must be cleaned thoroughly, removing any debris or dirt that could compromise adhesion. The shield should then be applied directly onto the roof deck, starting at the eaves and working upwards.Product Description. GRACE ICE & WATER SHIELD® has been the premier self-adhesive underlayment product used in domestic roof protection under shingles for more than 30 years. It has performed in the critical areas under the most severe climatic conditions to protect against wind-driven rain and the effects of ice dam build-up beneath the shingles..