Remember that there’s no such thing as a silly question. Here you can see what other homeowners have asked us about over the years. Chances are good you’ll find the answer to your question, too. If you can’t, help is just an email or a phone call away!

The following links, when selected, will provide information to frequently asked questions.

NOTE: Some of the information in this section is based on the technical bulletins published by the Asphalt Roofing Manufacturers Association (ARMA) and the Canadian Asphalt Shingle Manufacturers Association (CASMA).

FAQ’s About:

“CRC” means Canroof Corporation Inc.

For a glossary of residential roofing terms, click here.

Selecting A Shingle:


Installing Shingles:

Shingle Performance:

CRC Shingles and the Environment:

Roof Types and Designs:

General Information:

Q:   What are the most common asphalt shingle product and test standards?

A:  The most commonly found product and test standards are:

  • ASTM E108:  “Fire Tests of Roof Coverings” and ULC S-107:  “Fire Tests of Roof Coverings” are tests for roofs exposed to exterior fire hazards.  Roof coverings are rated as Class A, B or C.  Typically, glass shingle roof systems are Class A (including the underlayment) and organic shingle roof systems were Class C.   The Canadian equivalent for this requirement is ULC-S107.
  • ASTM D225:  “Asphalt Shingles (Organic Felt) Surfaced With Mineral Granules” is a product standard with requirements for organic shingles.  Organic shingles are no longer available.
  • ASTM D3018:  “Class A Asphalt Shingles Surfaced with Mineral Granules” is a product standard with some tests for Class A glass shingles.
  • ASTM D3161:  “Wind Resistance of Asphalt Shingles” is a laboratory wind test.
  • ASTM D3462:  “Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules” is a product standard with requirements for glass shingles.  All CRC glass shingles comply.
  • CSA A123.1-M:  “Asphalt Shingles Surfaced with Mineral Granules” is a product standard with requirements for organic shingles. Organic shingles are no longer available.
  • CSA A123.5-M:  “Asphalt Shingles Made with Glass Felt Saturated with Mineral Granules” is a product standard with requirements for glass shingles.  All CRC glass shingles comply.

Note:  Make sure that shingles purchased or used meet the required standard.

See CASMA Technical Bulletin No. 5 for more information.

Q:   Do CRC shingles meet the Canadian building code?

A:  All CRC shingles sold in Canada, meet the Canadian building code.

Q:   Why/when should I use an asphalt shingle underlayment?

A:  An asphalt shingle underlayment is typically dry felt that may be impregnated or coated with an asphalt saturant, or a synthetic sheet.  The use of an underlayment is recommended for the following reasons:

  • Resins may exude from the wood board decking.  Underlayment protects shingles from the resins that may be released.
  • Underlayments protect decking material from wind-driven rain that may penetrate the shingle layers.
  • To validate their limited warranties, many manufacturers require the use of underlayment.
  • The use of underlayments, particularly heavier grades, reduces “picture framing.”  According to CASMA, picture framing is the visible outline of deck panels caused by irregularities in roof decking thicknesses.
  • To obtain a Class A fire resistance rating, underlayments should be used underneath shingles.
  • The underlayment should conform with CSA 123.3-M (No. 15 / ASTM D226 Type 1 No. 15 felt), ASTM D 4869,  and/or CAN 2-51.32 (Breather Type Sheathing Paper) industry standards.

See CASMA Technical Bulletin No. 3 or ARMA Use of Asphalt Shingle Underlayment Form for more information.

Q:  Can I apply new shingles over existing shingles?

A:  Yes.  You can apply new shingles over existing shingles, depending on the condition of the roof.  If the roof has one layer of shingles that are lying flat and the deck is in good condition, the existing shingles typically do not have to be removed. Check with local officials to make sure that building codes are being followed.  During re-roofing is a good opportunity to examine roof ventilation to ensure vents are sufficient in number, positioned properly and are unobstructed.

See CASMA Technical Bulletin No. 6 or ARMA Re-roofing: Tear Off vs. Re-Cover Form for more information.

Q:  What offsets should be used for laminated shingles?

A:  For laminated shingles, CRC’s recommended offset is 4 – 10 inches.   Regardless of the shingle type, it is always best to follow all application instructions printed on the shingle package.  This will ensure proper roof performance and finished roof aesthetics.  All shingles must be applied with a minimum offset no less than 4 inches.

Q:   How can I ensure proper performance from shingles in cold climates?

A:  Proper performance from shingles installed and used in cold weather can be achieved by following the recommendations listed below:

  • Make sure that the roof is properly ventilated.
  • Be careful when using shingles in cold weather.  They tend to get brittle and may crack or break.  Try not to throw, drop or bend shingles.
  • If you are in an area that experiences freezing winter temperatures, eaves protection should be used to reduce water damage from ice dam formation.  Use self-adhering eave protector membranes.  They are easier to work with in cold weather.
  • Hand seal asphalt shingles in cold weather with an asphaltic cement recommended by the manufacturer.
  • When applying ridge caps, keep the shingles that are being used as ridge caps in a warm place so that they will be flexible enough to bend.
  • When re-covering an existing roof with new shingles, make sure that the old shingles are flat.
  • In areas that receive high amounts of snowfall, try not to damage shingles when removing snow.  Damage caused by snow removal is not covered under our limited material warranty.
  • Use caution if walking on a roof in the winter time.  The sealant bond between shingles can become quite brittle in cold weather.  Therefore, traffic on the roof may cause sealant bonds to break.

See CASMA Technical Bulletin No. 8 for more information.

Q:  Which type of fastener should be used to install asphalt shingles – nails or staples?

A:  CRC agrees with and supports the ARMA position that nails are the preferred method of fastening asphalt shingles due to their superior holding strength.  The following fastening tips apply to most CRC shingles; (check specific product application instructions for further information):

  • A minimum of four fasteners per shingle are used.
  • Correctly place and position fasteners below the sealant strip, but above the cut-out on three tab shingles, and in the nail line on laminated shingles.
  • The fasteners must be straight and flush with the surface of the shingle, not sunk into the shingle or sticking up at any point.
  • Make sure there is correct penetration of the deck as specified by ARMA and the NRCA.

See article on fastener requirements or ARMA Nail Application of Asphalt Strip Shingles for New and Recover Roofing Form for more information.

Q:   Do I need to peel the release tape off the shingles?

A:  The plastic release film on the back of CRC shingles does not need to be removed.

The sole purpose of this tape is to prevent the shingles from sticking together in the package.  Once the shingles have been removed from the package and are applied in the correct orientation on the roof, the release tape serves no purpose whatsoever.  The shingle sealant, which bonds the shingles together, is located elsewhere on the shingle and will seal succeeding courses of the shingles together on the roof when warmed by the heat of the sun, soon after application.

Q:  What is causing the algae growth on my shingles?

A:  Algae growth is typically seen on light coloured shingles.   It exists as a brown to black discoloration of the shingle and is caused by an algae known as Gloeocapsa.

Although algae may exist on a shingle, it does not affect the performance of the shingle.  Essentially, this is an aesthetic problem.

Most CRC shingles are now algae resistant, and covered by a Limited Algae Resistance Warranty.

See CASMA Technical Bulletin No. 13 or ARMA Algae Discoloration of Roofs Form for more information.

Q:  How do I get rid of the algae growth on my shingles?

A:  There are several ways to reduce the discoloration:

  • For a new roof, install a zinc or galvanized type metal near the ridge of the roof.   As the metal ions are oxidized and erode off of the metal strip, they wash down the roof inhibiting cellular algae growth.
  • A dilute solution of chlorine bleach, trisodium phosphate and water can be applied – one part chlorine bleach to three parts water with a quarter cup of trisodium phosphate.   Note:  Trisodium phosphate should be available at any paint supply store.   Gently spray the solution on the shingles.  For stains that are hard to remove, scrub mildly.  Scrubbing too harshly will remove granules.  Rinse the shingles thoroughly with water.  In the past, this has been a temporary solution and usually needs to be repeated every couple of years.  Apply this solution carefully to avoid damaging other parts of the building or the shrubbery below.
  • Some companies offer roof cleaning compounds or roof cleaning services.   Ensure the roof cleaning process will not damage the shingles.

See CASMA Technical Bulletin No. 13 or ARMA Algae Discoloration of Roofs Form for more information.

Q:  Can bird excrement affect asphalt roofing products?

A:  A build-up of bird excrement on asphalt roofing products can have negative effects, if it remains on the product for a considerable amount of time.   In some instances, it can even shorten the life of the product.  A web search may reveal companies that offer products to mitigate bird roosting/nesting on your roof.

Q:  Can hail affect asphalt roofing shingles?

A:  Hail can affect asphalt roofing shingles.  The damage caused by hail can be classified into two groups:  aesthetic damage and functional damage.   Aesthetic damage results in slight granule loss and the life of the shingle is usually not affected.  Functional damage is characterized by substantial granule loss or cracking or penetration of the shingle.  Functional damage may result in short term leaks or a reduction of the life expectancy of the shingle.

According to CASMA Technical Bulletin No. 14, there are several factors that impact how roofing shingles perform in hail:

  • Size and density of hail stones – Larger heavy stones will cause more severe damage.
  • Age of the shingles – Newer shingles are more resistant than older shingles, as the asphalt is less brittle and better able to absorb the impact energy.
  • Angle of hail impact – Hail which strikes the roof at a 90° angle is more likely to cause shingle fractures, while hail that strikes the roof obliquely is more likely to result in spots of granule loss.
  • Temperature – Colder temperature will be more likely to cause fractures as the asphalt will be more brittle than in warmer weather.
  • Roof deck conditions – Solid roof decks on moderately spaced trusses offer better support to the shingle surface in resisting hail damage.  Shingles on rotted or flimsy decking can be more easily fractured.

See CASMA Technical Bulletin No. 14 for more information.


Q:  What is buckling?

A:  Buckling is defined as ridges that form along the length of the shingle, with the ridge spacing usually coincidental with deck board joints.  These ridges are caused by the shingle being distorted from the movement of the deck.   Buckling can occur with any deck type, but is more common with board decks, and less common on plywood/OSB decks.  Buckling can occur when a new roof is installed, even if the old roof did not show any buckles; when the roof is stripped, the deck may be exposed to moisture, causing dimensional changes in the supporting lumber.

See CASMA Technical Bulletin No. 9 or ARMA Plain Facts About Buckled Shingles Form  for more information.

Q:  How can I reduce the chance of having buckled shingles?

A:  The following will help to prevent buckling:

  • Apply shingles as specified by the manufacturer.
  • Make sure you have sufficient attic ventilation.
  • Decking material should not be exposed to water before or after application.
  • Use manufacturer approved wood decking materials and make sure that they are conditioned to be at moisture equilibrium with the job site environment.
  • Cover older dimensional lumber decks with a thin plywood sheathing prior to shingle installation.

See CASMA Technical Bulletin No. 9 or ARMA Plain Facts About Buckled Shingles Form  for more information.

Q:  My shingles are buckling.  What should I do?

A:  There are a couple of things that you can do to correct this problem:

  • Make sure that the attic is well ventilated to reduce moisture build up.  You may need to install additional vents.
  • Remove the fasteners from the shingles that have been affected and refasten.  You may want to replace any the buckled shingles as well.

See CASMA Technical Bulletin No. 9 or ARMA Plain Facts About Buckled Shingles Form  for more information. 

Q:   Should I be concerned about small bubbles / blisters on my shingles?

A:  No.  Practically all asphalt shingles have, by the nature of their manufacture, a greater or lesser degree of blistering potential under certain conditions or combinations of conditions.  Generally, blistering is difficult to see from ground level and does not necessarily shorten the life of the shingle.

See CASMA Technical Bulletin No. 21 for more information.

Q:  What is colour shading?

A:  A roof observed from different lighting conditions or angles may have darker or lighter spots in certain areas.  This apparent difference in colour is referred to as “shading.”  Shading is usually caused by unavoidable slight variations in texture which occur during the shingle manufacturing process.

Black or dark coloured shingles are more prone to shading problems.  A small amount of light is reflected from dark surfaces.  Therefore, even slight textural differences may cause shading.  Light coloured shingles reflect greater amounts of light than darker shingles and as a result it is harder to notice shading problems.  Since blends are made from a number of colours, shading differences are masked and are even less noticeable.

The material on the back of a shingle is sometimes transferred to other shingles that are next to it.  Also, when shingles are stacked too high or stored for long periods of time, stains can develop.  Both conditions can create the appearance of shading.   These are only temporary aesthetic issues and will naturally weather off.  Note:   Shading does not affect the watershedding performance or life expectancy of a shingle.

See CASMA Technical Bulletin No. 17 or ARMA Colour Shading of Asphalt Shingle Roofs Form for more information.

Q:  What can I do to reduce the potential for shading?

A:  To reduce the potential for shading:

  • Do not mix shingles with different production codes on the same roof.
  • Make sure you follow the application instructions provided on the shingle wrapper, and also available on this web site.
  • Apply the shingles starting from the bottom of the roof and move across and up.
  • Use blended shingle colours instead of solid colours.
  • Do not stack shingles higher than what is recommended by the manufacturer.
  • Do not store shingles for long periods of time.

See CASMA Technical Bulletin No. 17 or ARMA Colour Shading of Asphalt Shingle Roofs Form for more information. 

Q:  My gutter is filled with granules.  Is there a problem with my shingles?

A:  Not necessarily.  An excessive amount of granules are applied during the shingle manufacturing process to make sure that the asphalt on the roofing sheet is completely covered.  It is important to completely cover the sheet with granules so that the asphalt is not exposed to ultraviolet light.

The granules are then pressed in.  Due to the excessive amount of granules applied, some of the granules are only held loosely in place.  Most of the excess granules are removed by the shingle manufacturing process, but some of these granules do get packaged with the shingles.  These excess granules are known as “hitchhiker” granules.

“Hitchhiker” granules will typically come off during the first few years of shingle exposure on the roof.  They usually will be found in gutters or at the bottom of downspouts.  The loss of these granules is normal and does not affect the performance of the shingle.  Granule loss only becomes a problem when much of the asphalt becomes exposed on the surface of the shingle.

See CASMA Technical Bulletin No. 18 for more information.

Q:  What is fishmouthing?

A:  Fishmouthing is the raising of a portion of the front edge of a shingle to create an “eyebrow” appearance.  This may occur at the lower tab edge or along the cutout edge.  These distortions may be more noticeable on certain roofs because of the slope, sunlight and shingle colour.  These “fishmouths” do not affect the life expectancy of the shingle, and they do not result in leakage, blow-off or other shingle problems.

See CASMA Technical Bulletin No. 4 for more information.

Q:  What causes fishmouthing and how can it be corrected?

A:  Fishmouthing can be caused by:

  • Nails or staples that are raised.
  • Foreign matter under the shingle.
  • Wrinkled underlayment felt.
  • Damaged shingles or shingles that are bent prior to application. Fishmouths are primarily an aesthetic problem.  Typically, fishmouthing is repaired in temperate weather by sealing the shingles flat with hot melt glue.

See CASMA Technical Bulletin No. 4 for more information.

Q:  What is a splice?

A:  Large rolls of glass mat are used in the shingle manufacturing process, and a splice is a glued or taped lap of the end of one roll to the beginning of the succeeding roll.  Rolls of glass mat must be spliced together to maintain continuous shingle production.  Each splice is marked for rejection before the shingles are packaged.  Occasionally, an error or oversight occurs where that splice gets packaged along with the shingles.  Shingles containing a splice may delaminate on the roof, and should be replaced.

Q:  What is winter curling?

A:  When the front edge of a shingle tab lifts to form a shallow “U” saucer shape in cold weather and flattens when the weather is warmer, this phenomenon is known as winter curling.  Sometimes, the entire front edge of a shingle may lift uniformly.

When the top surface of the shingle is cooled, this part of the shingle contracts.   At the same time, the bottom of the shingle receives a certain amount of heat from the attic, especially if the attic ventilation is insufficient.  As a result, the shingle curls slightly.

The appearance of winter curling depend on:  the age of the shingle, whether the attic is sufficiently ventilated, the type of shingle, roof pitch, humidity and climate.   Complete elimination of winter curling is rare, although the durability and watershedding properties are not affected.

See CASMA Technical Bulletin No. 7 for more information.

Q:  Are asphalt shingles good for the environment?

A:  Shingles are relatively good for the environment because they protect your home/building from damage from the elements. They are durable, lightweight, and are easily maintained. See the attached industry bulletin from the Canadian Asphalt Shingle Manufacturers Association which outlines other environmental benefits.  See CASMA Technical Bulletin No. 27.

Q:  What is meant by “sustainable development”?

A:  A sustainable development is generally defined as a development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Q:  How can I compare different shingle brands to see how green they are?

A:  There are a number of environmental programs which give standards and limits for various aspects of shingles (i.e. recycled content, longevity, use of local raw materials, etc.).

Q:  What are some programs that rate different aspects of sustainable building products/practices?

  • A:  At this time some of the major ones are:
  • LEED™
  • Built Green™
  • NAHB
    There are many others, including regional variations of the ones listed above. Each program asks questions and then “awards” credits or points so you can quantitatively compare different building practices and materials, including shingles.

Q:  Which environmental program should I use?

A:  The choice is completely up to you. Look at each program and determine which one suits your needs.

Q:  What is ENERGY STAR™?

A:  ENERGY STAR™ is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy designed to encourage builders/homeowners to save money and protect the environment through energy efficient products and practices.

Q:  How does ENERGY STAR™ work for shingles?

A:  The shingles must have a minimum solar reflectance (tested right out of the package and again after three years on the roof) and a comparable (with non-approved shingles) limited warranty program. It is assumed that better shingle solar reflectance, if used on every roof within an urban area, may reduce the overall temperature in cities (heat island effect), which in turn would lower the energy load needed for air conditioning. In terms of the practical benefit to the individual home directly, shingle colour is irrelevant to home heating and cooling costs since the attic floor is typically well-insulated and the attic is also ventilated.   Note that in Canada, Energy Star ratings do not apply, as per Natural Resources Canada.

Q:  Are there any financial advantages for using ENERGY STAR™ approved shingles?

A:  There may be some tax advantages with using ENERGY STAR™ approved shingles in some areas; check with your local government.

Q:  What is Built Green™?

A:  Built Green™ is an environmental building program, developed in partnership with various government agencies. Built Green is designed to help home-buyers find quality, affordable homes that offer opportunities to protect the health of their families and the environment. Currently Built Green™ is more popular in the west, but it is expanding across the country.

Q:  How does Built Green™ work for shingles?

A:  Built Green™ has a checklist of “Built Green™ approved” brands. Their criteria is based on limited warranty period (the longer a product’s limited warranty period, the more points you get; 2 points for 25-year products, and 1 point for each additional 5 years up to a maximum of 4 points). CRC has a number of products on the “approved” list. There is an additional requirement for recycled content (minimum 25% recycled content equals 3 points (the most a product can get), etc. CRC shingles do not meet this requirement.

Q:  What is LEED™?

A:  LEED™ is an acronym for Leadership in Energy and Environmental Design. It is a program sponsored and administered by the U.S. Green Building Council (and by Canadian Green Building Council in Canada). LEED™’s purpose is to provide a rating system that encourages designers and builders to choose “green” building products for the construction and operation of buildings. While there are currently dozens of other environmental programs (such as Built Green, and Green Globes), LEED™ seems to be the major one at this time.

Q:  How does LEED™ work?

A:  When you have a LEED™ project, the design, location, materials, and how the project affects the surrounding area can earn you credits. If you attain a certain number of credits your project will be awarded a Platinum, Gold, or Silver, certification. It should be noted that neither manufacturers nor products can be “LEED™ certified”.

Q:  How can CRC products help the designer earn LEED™ credits?

A:  Our building product can help earn credits in the areas of insulation, reflective coatings, recycled material, and regional material.

Q:  Which CRC products can earn LEED™ credits?

A:  All shingles have a certain recycled content, but the amount may not be high enough to obtain LEED™ points. Our ArmourCoat roof coating would qualify as a reflective product. (it is also ENERGY STAR™ approved). EnerFoil can help with energy efficient design credits. Depending on the project location, our products could qualify for regional material credits.

Q:  What Is NAHB?

A:  NAHB is the National Association of Home Builders and they are a Washington, D.C.-based trade association whose mission is to enhance the climate for housing and the building industry. Chief among NAHB’s goals is providing and expanding opportunities for all consumers to have safe, decent and affordable housing. As “the voice of America’s housing industry,” NAHB helps promote policies that will keep housing a national priority.

Q:  Does NAHB have a “green “program?

A:  Yes. Their program is called “NAHB National Green Building Program”.  Points are primarily awarded based on a building material’s recycled content (no minimum level is given). In the roofing section specifically, one can earn a point simply by using an ice and water protector.

Q:  How do I know an CRC product qualifies for an environmental program?

A:  Ask the building designer what the requirements are, i.e. what environmental program they’re using, or what product characteristics they need to have. We have a number of products which will meet the requirements for recycled material, reflectivity, regionally produced material, etc.

Q:  Can you give us a list of the number of credits for each CRC product?

A:  No. The requirements for each program keep changing, so it is best to contact CRC Technical Support for the latest requirements and compliances. LEED™, for example, is broken down into 9 Standards (e.g. New Construction, Homes, etc.) and each one has different requirements (see table below). So you must first determine what the criteria are and then contact CRC Technical Support 800-268-0878 ext. 3403. They will provide you with the latest data.

Q:  How can I provide documentation to show the data for the different CRC products?

A:  Typically the building designer will have a form that needs to be completed. Send the form to CRC Technical Support and they will complete the form and return it to the designer.

Q:  Are my old shingles recyclable?

A:  Many local government agencies and private companies have started recycle programs for used shingles. The shingles can be recycled into road paving material and other materials. Check with your local government. It is important to note that the old shingles may need to be “clean”; i.e. free of any nails, wood or other foreign material which can often end up as included in roof tear-off material. CRC recycles almost all of its manufacturing waste into other uses, such as road paving materials.

Q:  What is a drip edge and how is it applied?

A:  Drip edges are used for watershedding at the eaves and rakes and for preventing wood materials from rotting.  It is important that the drip edge is “made of a corrosive-resistant material that extends approximately three inches back from the roof edges and bends downward over them.”  (ARMA Residential Asphalt Roofing Manual)

The drip edge should be applied beneath the underlayment or eave protection along the eaves and over the underlayment on the rakes.

Q:  What are low slope roofs?

A:  Roofs that have slopes of 4:12 or less are considered to be low slope roofs.  (4:12 means a vertical rise of 4 inches for every 12 inch horizontal run, or 18.4°). Never apply asphalt shingles to slopes that are below 2:12 (9.5°).  Shingles applied on low slope slopes do not last as long as shingles on steeper roof pitches, due to the increased exposure to sunlight and other weather conditions.  Generally, laminated/architectural shingles are better suited to steep roofs, where their enhanced aesthetics are more readily visible.

Q: How can I reduce some of the problems associated with low slope roofs?

A:  Low slope roofs are more susceptible to water entry due to ice dams and wind-driven rain.  Therefore, the key to a successful low slope roof is to increase the watershedding properties of the roof system.

Rain and melting snow do not run off quickly on low slope roofs.  As a result, the potential for ice dams is increased.  By providing adequate ventilation the formation of ice dams can be decreased.  Note:  “The National Building Code of Canada allows various types of ice dam membranes to be used, but CASMA recommends that self-adhering modified asphalt membranes be used.”  (CASMA Technical Bulletin No. 16)

Wind-driven rain is another concern associated with low slope roofs.  By improving the underlayment or by using a special shingle application method, the damaged caused by wind-driven rain can be reduced.

See Bulletin on Applying Shingles on Low Slopes or CASMA Technical Bulletin No. 16 for more information.

Q:   I want to shingle my roof.  How many shingles will I need?

A:  By using simple calculations you can estimate the number of shingles that will be needed to complete the job.  Roofs come in many shapes and sizes and can be classified into simple geometric shapes such as squares, rectangles, trapezoids and triangles.  To determine how many shingles will be needed you must calculate the area of the roof.  This is done by figuring out what geometric shapes make up your roof, calculating the area of the individual shapes and summing the areas to give you the total area of the roof.  The area required is then divided by the area each bundle covers.  Don’t forget to add allowances for ridges, starter strips, etc.

See article on Estimating How Much Roofing Is Required for more information.

Q:   What will happen if my roof is not properly ventilated?

A:  Insufficient ventilation can lead to:

  • Asphalt odours from hot shingles entering the home’s interior.
  • Blistering, fishmouthing, curling or premature aging of asphalt shingles.
  • Rotting of wood decks.
  • Buckling.
  • Splitting.

Proper ventilation is essential so that air movement is not restricted beneath the roof surface.

See CASMA Technical Bulletin No. 1 or ARMA Ventilation and Moisture Control for Residential Roofing Form for more information.

Q:  How much ventilation do I need on my roof?

A:  The amount of ventilation needed is determined by the size and design of the roof.  For roof and attic spaces above an insulated ceiling, the vent ratio is one square foot of net free ventilating area/300 square feet.   For low slope roofs or roofs with cathedral ceilings the vent ratio is one square foot/150 square feet.

See CASMA Technical Bulletin No. 1 or ARMA Ventilation and Moisture Control for Residential Roofing Form for more information.

Q:   Are CRC roofing products required to have Material Safety Data Sheets (MSDS)?

A:  The following roofing products do not require MSDS’s, as they are either considered manufactured articles or are made predominantly of wood:

  • Organic Based Roofing (Shingles, Rolls, Felts)
  • Fibreglass Based Roofing (Shingles, Rolls, Felts)
  • Roofing Asphalt
  • APP and SBS Modified Bitumen Roofing
  • CRC Ice and Water Protectors (Goldshield, StormTamer™, StormShield™, & ArmourGard)

CRC does offer Material Information Sheets for these product families (downloadable from this web site), which offer similar information as one might find on an MSDS.

Q:  If I have a shingle concern, what should I do?

A:  If you have a shingle concern (e.g. splice, severe granule loss, etc.), please contact the Warranty Services Department in your area (Eastern Canada 1-800-361-5836; Western Canada 1-800-521-8484).  You will be required to submit a copy of the proof of purchase.  After verifying that the shingles purchased were from Canroof Corporation Inc., a package will be sent to you, requesting more information photos, and samples.

Q:  Can I paint my roof?

A:  Yes.  The affect of paint on shingles if very negligible.  Technically, it could be argued that the paint will help the shingles weather longer.  Some roof coatings that are advertised to extend product life are simply premium quality latex paints.

Q:  Do I have to use a certain type of paint on my roof?

A:  Yes.  Latex paints must be used.  Latex paints will do nothing more than colour the shingles.  On the other hand, oil-based paints may soften the shingles slightly due to the solvents that they contain.  These solvents will evaporate quickly so if used carefully, there should not be any lasting effects.   Generally regardless of paint used, paint weathers off of the shingles within five years.  How long the paint lasts depends on the quality of the paint, the pitch of the roof, climate, etc…

Q:  How are shingles made?

A:  Shingles are made in a continuous web process.  Large rolls of glass mat are unwound and fed into the coater.  At the coater, coating (asphalt with air blown through it) is applied to the top and bottom surfaces of the sheet. Mineral stabilizers are added to the coating which improve the shingle’s fire resistance and weatherability.  Next, granules are applied to the top surface of coating.  Granules are ceramically coloured crushed rock; the granules give the shingle its colour, but more importantly protect the coating from ultraviolet light.  Backsurfacing is then applied to the sheet to prevent it from sticking to the machine and to other shingles when packaged.  The release tape is also applied to the back of the sheet to prevent the sealant buttons from sticking to the next shingle in the package.  The granules are then pressed into the topcoating.   Once the sheet is cooled, sealant buttons are applied.  The sealant buttons allow one shingle to bond to the overlying shingle on a roof, to prevent wind uplift.  The roofing sheet is then measured and cut into shingles.  At this stage, the two pieces of laminated shingles are adhered together.  The shingles are wrapped into bundles and stored in the warehouse until they are ready to be shipped to the appropriate location.

See article for more information.

Q:  What are ice dams?

A:  Ice dam formation is the result of continuous freezing and thawing of snow due to escaping heat from the house or from gutters being backed up with frozen slush.  When this occurs, water may be driven under the roof which may cause ceiling, wall, insulation and gutter damage.

See CASMA Technical Bulletin No. 10 or ARMA Preventing Damage from Ice Dams Form for more information.

Q:  What can I do about ice dams?

A:  Ice dams can be preventing from forming by:

  • Installing a vapor barrier above the home’s warm space.
  • Insulating the attic floor.
  • Ventilating the attic.
  • Damage from ice dams, if they do form, can be reduced by:
  • Removing debris from gutters so that it does not build up over time.
  • Making sure that the outer edges of the gutters are lower than the slope line.  This will allow for snow and ice to slide clear.
  • Installing eaves flashing, such as CRC’s ArmourGard Ice & Water Protector

See CASMA Technical Bulletin No. 10 or ARMA Preventing Damage from Ice Dams Form for more information.

Q:   Can I use salt to remove the ice on my shingles?

A: Yes, but there are some drawbacks to doing this, such as possible downslope corrosion of metal gutters and roof equipment, and the salt may leave a temporary whish residue on the shingles once the melted ice has evaporated.

See CASMA Technical Bulletin No. 15 for more information.

Q: Can I use a shovel to remove snow and ice from my shingles?

A:  This activity is not recommended.

See CASMA Technical Bulletin No. 15 for more information.