Architectural Grade Composition Roofing
Developed in the 1970s for use on high-end homes, dimensional shingles are offered for homeowners who want a shingle that retains the architectural appearance of a cedar shingle with the high performance of asphalt. Layered construction lends an appearance that is a lot like cedar shakes. These shingles are also sometimes referred to as laminated architectural shingles, or as dimensional or composite shingles. This type of shingle is constructed with a heavy base fiberglass mat affixed to multiple material layers of asphalt to create a layered, three-dimensional look. Three-tab shingles are usually constructed to be flat without any dimensional thickness. In fact, architectural shingles generally outweigh 3-tab shingles by 50 percent.
What Are My Choices?
When comparing the different grades of composition shingles, there are generally three different choices.
- Presidential grade – The heaviest and thickest shingles and often rated as 50-year shingles
- Architectural Grade – Medium weight shingles often rated between 25-40 years by various manufactures
- Three-Tab – The lightest weight and often rated as 20-15 years by various manufacturers
It is important to note that most manufacturers’ warranties are “product defect” warranties and are not a reliable indicator of functional roof life expectancy or reliability of the roof.
Roofs Are Systems, Not Shingles! Their Useful Service Life and Reliability Depend On:
- The quality of the workmanship of the installation,
- The type of fastening method used
- The quality and installation method of the flashings used
- The quality and installation methods for the underlayment
- The exposure of the roof and the climate zone of the house
- The slope of the roof and the overall roofline and roof design – complex rooflines are much more likely to have moisture control problems than simple rooflines.
What About The Weight of The Shingle? Does A Heavier Shingle Help?
Because dimensional composition shingles are heavier, they are less likely to undergo warping and provide great resistance to the wind than standard 3-tab shingles which are usually rated for normal wind speeds. While most architectural shingles can withstand winds of up to 120 mph if correctly installed. Because laminated architectural shingles are heavier than 3-tab shingles and have the strength of multiple shingles, they can withstand stronger winds and more intense weather conditions. 3-tab shingles are much more vulnerable to wind, and can sometimes even be ripped away during stormy conditions. Laminated shingles typically last and retain their appearance longer than 3-tab shingles.
Are Composition Shingles Recommended on Low-Slope Roofs?
Composition shingles should not be used for low slope, under 2/12 roofs, and should have augmented vapor barrier protection for roofs between 2/12 to 4/12 slope.
Do Dimensional Shingles Cost More?
Cost also separates architectural and 3-tab shingles. Usually, you can expect to pay at least 20 percent more for architectural shingles than for standard three-tab shingles, even more for the longer life span versions claiming 40 and 50 years of protection. This is true across nearly any brand, including popular brands like Owens Corning and Malarkey. In fact, some of the higher-end architectural laminate shingles can cost twice as much as 3-tab varieties.
If you are looking to replace an existing composition roof, the architectural grade shingle is a good choice and probably the most commonly installed roofing material in many climate zones. It is always a good idea to select at least three proposals from different installers and remember that the quality of the installation is more important than the type of shingle you choose. Many reputable roofing companies offer workmanship warranties for their roofs, so I would look carefully at the proposals you get to try and flush out differences in the quality of the installation and the warranty.
Further information: http://roofing-architectural-shingles.wikispaces.com/Types+of+Roofing+Shingles+-+Advantages+and+Disadvantages
Seattle Roof Advisor http://www.seattleroofadvisor.com/composition.html