CASMA Technical Bulletins

Bulletin #30 Hot Weather Recommendations for Application of Asphalt Roofing Shingles (2010-01-29)

Asphalt roof shingles have been used successfully in various climatic zones around the world for many decades, including desert and tropical regions. Improved application efficiency, and more importantly, enhanced long-term shingle performance can be achieved by following some of the hot weather application recommendations outlined...

Bulletin #29 Sampling of Shingles for Compliance to CSA Standards (2009-11-25)

Asphalt shingles that conform to Canadian Standards Association (CSA) specifications have a proven track record of performance, meeting or exceeding customer expectations. When compliance to CSA standards or manufacturer�s specifications needs to be established for a specific lot of shingles, there is a CSA-approved method for sampling the lot which should be followed. The methodology covers timing, sample size and sample selection...

Bulletin #28 Use of Roof Water Run-Off (2008-07-31, Revised: 2012-03-01)

In some regions, homeowners may want to use their roof water run-off from rain for various domestic/household purposes. While asphalt shingles are considered safe in terms of groundwater and leachate contamination (they do not contain heavy metals or toxic chemicals based on groundwater leachate testing), all roofs, regardless of materials used, collect environmental contaminants that may render the water run-off unfit for human consumption...

Bulletin #27 Asphalt Shingles and the Environment (2008-07-31, Revised: 2012-03-01)

Homeowners and businesses alike are more focused than ever on building "green", and on how their actions affect the world around them. Demand is high for eco-friendly products that minimize the impact on the natural environment. At the same time, the customer still demands that there be no compromise on the performance and look that both protect and enhance his property's value...

Bulletin #26 Usefulness and Qualifications of Roofing Granules (2007-07-02, Revised: 2012-03-01)

Roofing granules are in essence what gives asphalt shingles their aesthetic appeal. The blend of colors, depth and richness of appearance are nothing short of an individual manufacturer's artistic creation and imagination. Although appreciated mostly for their appearance, roofing granules serve an even more important role than aesthetics...

Bulletin #25 Proper Installation of Drip and Rake Edges (2007-02-22)

When replacing shingles on a roof, it is important to give proper consideration to flashing details on the drip and rake edges. Although drip edges are not currently required by the National Building Code, they are good roofing practice...

Bulletin #24 Shingle Release Film (2007-02-22, Revised: 2012-03-01)

Asphalt shingles have been a commonly used roofing material for almost a century. Early asphalt shingles were often applied with an asphalt or tar adhesive to enhance wind resistance. In the 1950's shingles were introduced with a factory-applied asphalt adhesive sealant strip. The sealant strip on those shingles was protected by an overlying loose film that needed to be removed during shingle installation...

Bulletin #23 Applying Shingles on Steep Slopes and Mansard Roofs (2006-09-12)

With the advancements and changes in architectural design, steep slope (including mansard) roof shingle applications are becoming more common. Unfortunately, steep slopes can reduce the effectiveness of standard nailing patterns and the ability of factory applied sealing strips to perform their desired function...

Bulletin #22 "Troughing" of glass shingles (2001-01-19, Revised: 2012-03-01)

If, like most Canadians, you have decided to roof your home with asphalt shingles, you may know that there are two different "types" to choose from. These two types are commonly known as "organic" and "glass". These names relate to the type of fibre used to make the base reinforcing fabric upon which the shingle is constructed...

Bulletin #21 Blistering of asphalt shingles (2001-01-19, Revised: 2012-03-01)

In studying the causes of various types of blistering with a view to minimize the blister potential, much has been learned about the behaviour of blistering shingles. Typically asphalt shingles only blister where the exposure conditions on the roof include one or more of the following...

Bulletin #20 Asphalt shingles - organic or glass? (2000-07-07, Revised: 2012-03-01)

Organic shingles are made on a thick felt of wood and other cellulose fibres. Glass shingles are made on a mat of non-woven glass fibres, which are held together with a water-insoluble binder. Both shingle types contain asphalt, are covered with mineral granules and are available in a wide variety of product weights, styles and colours...

Bulletin #19 Colour fading of roof shingles (2000-01-20)

Asphalt shingles are covered with mineral granules to protect the asphalt from UV radiation, and provide a degree of fire resistance. The granules are coloured to provide different roof colours, and are generally of a natural stone, which is coated using colour pigments...

Bulletin #18 Excess roofing granules on shingles (1999-05-10, Revised: 2012-03-01)

During the roofing manufacturing process, roofing granules are applied into the hot top coating asphalt. An excessive amount of granules is used to provide total and complete coverage of the asphalt. The asphalt must be completely covered to ensure protection from solar ultraviolet radiation...

Bulletin #17 Colour shading of asphalt shingle roofs (1998-09-28)

As a roof is viewed from different angles, and/or different lighting conditions, certain areas may appear darker or lighter. This inconsistency in colour is commonly called "shading"...

Bulletin #16 Installation of asphalt shingles on low sloped roofs (1998-09-28, Revised: 2012-03-01)

Asphalt shingles are an effective roof covering material for sloped roofs. They can be successfully used on "low sloped" roofs as well as steeper pitches. Typically any roof slope less than 4:12 (i.e. 4" of vertical rise for every 12" of horizontal run, or 18.5�) is considered a low sloped roof. Asphalt shingles can be successfully applied to these lower slopes, providing a few special application procedures are followed...

Bulletin #15 Severe icing of asphalt shingle roofs (1998-01-22, Revised: 2012-03-01)

Occasionally, winter weather conditions may result in the formation of a thick layer of ice on asphalt shingle roofs. Although this ice layer will have little direct physical effect on the shingle themselves, there could be instances of roof leaks due to the ice...

Bulletin #14 Effects of hail on asphalt roofing shingles (1997-05-05, Revised: 2012-03-01)

Asphalt roofing shingles have historically demonstrated excellent performance in a variety of weather conditions; rain, sun, ice, snow, and sleet. Hail storms, however, may produce hail of sufficient size to cause visible damage to the shingles...

Bulletin #13 Algae discoloration of roofs (1997-05-01, Revised: 2007-05-30, 2012-03-01)

Occasionally light coloured asphalt shingle roofs may discolour with a brown to black stained appearance. Although this staining sometimes is mistaken as dirt, moss, or even granule loss, it is caused by a species of algae known as Gloeocapsa. Natural pigments produced by the algae cells result in the dark discoloration, usually visible after the roofs are about five to ten years old...

Bulletin #12 Water soluble light asphaltic oils (1997-05-05, Revised: 2012-03-01)

The occurrence of water soluble light asphaltic oils, also known as "tobacco-juicing" for its color resemblance, is the normal result of the weathering of all asphalt-based products...

Bulletin #11 Wind protection of asphalt shingle roofs (1997-05-05, Revised: 2012-03-01)

Asphalt shingles, when installed properly, have proven to be very resistant to strong winds. Though most shingle manufacturers warrant their shingles for wind speeds up to about 100 km/h (60 miles/h), reducing roof damage caused by wind can be accomplished by taking some simple precautions, especially if you are in an area known to have periodic high winds or very dusty conditions...

Bulletin #10 Preventing problems from ice dams (1996-10-11, Revised: 2001-10-05, 2012-03-01)

Roof structures will sometimes fail due to the formation of ice dams. Ice dams are formed by the continuous melting and freezing of snow due to heat escaping from the house or by the backing up of frozen slush from the gutters. The melted water flows under the snow and freezes as it reaches the unheated soffit, thus creating the ice dam...

Bulletin #9 Buckling of asphalt shingles (1996-10-11, Revised: 2012-03-01)

Asphalt shingles occasionally show buckles or ridges along the length of courses up the roof. This buckling is the result of the shingles being distorted due to movement of the roof deck on which they are applied. Asphalt shingles have never been shown to buckle by themselves...

Bulletin #8 Cold weather recommendations for application of asphalt roofing shingles (1996-02-19, Revised: 2012-03-01)

Asphalt roof shingles have been used successfully in North American and European cold climates for over ninety years. Improved application efficiency, and more importantly, enhanced long-term shingle performance can be achieved by following some of the cold weather application recommendations outlined...

Bulletin #7 Curling of asphalt shingles during winter (1994-02-15)

Winter curling is a phenomenon affecting asphalt roofing shingles whereby the front edge of the shingle lifts up slightly from the roof deck when cold, then lays flat again during warmer weather...

Bulletin #6 Re-roofing (1993-08-29, Revised: 2012-03-01)

When the time has come to re-shingle your roof, one decision you will be faced with is whether to strip off the old shingles, or apply the new ones right over the existing layer. There is no easy answer. Although each roof must be evaluated individually, there are some general guidelines you can follow to help you make an informed decision...

Bulletin #5 Asphalt shingles test standards (1993-06-15, Revised: 2012-03-01)

Asphalt roofing shingles sold in Canada may have various agency conformances shown in short form on the bundle packaging. Those most commonly found are described briefly below to help the consumer understand their meaning and assist him in purchasing the product best suited to his needs. More information can be obtained by contacting the manufacturers directly...

Bulletin #4 Distortions on asphalt shingles (1993-01-19)

Occasionally, asphalt shingles may distort slightly along their leading edge to create a small bump somewhere along the length of the shingle. Typically, the remainder of the shingle lays flat and looks fine in all other respects. These bumps may be more noticeable on certain roofs because of slope, sunlight, shingle colour, viewer angle, etc...

Bulletin #3 The Use of Underlayment With Asphalt Shingles (1992-09-01, Revised: 1997-04-01, 2001-06-04, 2006-09-12, 2012-03-01)

There are many reasons why the use of asphalt-saturated felt as an underlayment prior to applying asphalt shingles makes good roofing sense...

Bulletin #2 Ventilating Roofs Over Cathedral Ceilings (1992-06-01, Revised: 2012-03-01)

Cathedral ceilings covered with asphalt shingles require adequate ventilation like any other roof to prevent damage to the shingles. There should be a minimum space of 2 inches between the roof sheathing and the insulation to allow for the unobstructed air movement...

Bulletin #1 Proper Ventilation for Asphalt Shingle Covered Roofs (1992-02-01, Revised: 1996-10-16, 2012-03-01)

Although not usually recognized as a major design consideration, the proper ventilation of the attic area is an essential factor in gaining the maximum service life out of the building materials used in the roof assembly, in addition to improving heating and cooling costs...