In August, the Asphalt Roofing Manufacturers Association (ARMA) published an updated, revised edition of its Asphalt Roofing Residential Manual. The manual is intended to provide good practices relating to asphalt shingles, roll roofing and self-adhering roll roofing used in residential roofing applications. But because manufacturers' instructions may vary from ARMA's guidelines, it is important for roofing professionals to compare ARMA recommendations and manufacturer instructions.
Chapter review
The 2006 edition of ARMA's manual consists of 18 chapters and 124 pages; the previous 1997 edition consists of 14 chapters and 104 pages. The most obvious difference with the new manual is it addresses three-tab strip shingles and architectural laminated shingles separately. Also, additional chapters address flashing conditions, application of hip and ridge shingles, and application of self-adhering roll roofing.
The new manual's initial chapters address the advantages, manufacturing and selection of asphalt roofing products; design considerations; estimating how much roofing is required; and preparing for a job.
Chapter 7—Application of Shingles on New Construction—Deck Preparation addresses underlayment application. In this chapter, ARMA recommends underlayment be installed over the flange of drip-edge flashing at eaves and the drip-edge flashing be installed over the underlayment at rake edges. Also, ARMA indicates Style-D drip-edge flashing is preferred but use of 90-degree drip-edge flashing is acceptable.
Chapter 8—Application of Strip Shingles on New Construction provides guidelines for applying three-tab strip shingles using the 6-, 5- and 4-inch methods. If a roof surface is broken by a dormer or valley, ARMA recommends applying shingles from a rake edge and working toward a dormer or valley. If the surface does not contain a dormer or valley, ARMA recommends installation start at the most visible rake edge. If both rakes are equally visible, ARMA suggests starting at the roof surface center and working in both directions; this same method would apply for hip roofs. Snapping a vertical chalk line in the center of a roof surface will help installation in either direction.
Chapter 9—Application of Laminated Shingles on New Construction provides guidelines for applying architectural laminated asphalt shingles. For example, ARMA recommends bonding the first shingle course to the underlying starter strip by placing a quarter-sized spot of asphalt roof cement beneath each shingle corner and two more spots equally spaced between the ends of shingles. This recommendation only applies to architectural laminated shingles and not three-tab strip shingles.
Chapter 10—Flashing provides guidelines for properly terminating asphalt shingles against side walls and front walls, at soil and vent stacks, and at chimneys. ARMA recommends metal flashing shingles be a minimum of 10 inches long and 2 inches wider than the shingles' expected exposures. For example, for shingles with 5-inch exposures, metal flashing shingles measuring 10 inches by 7 inches with the 10-inch length bent at a 90-degree angle should be positioned to extend 5 inches onto the roof deck and 5 inches up the wall surface.
Chapter 17—Inspection of the Completed Job provides guidance for post-job final inspections. ARMA suggests paying special attention to proper fastening; broken, torn or damaged shingles; chimney, vent pipe and side wall flashings; hip and ridge shingles; overhands; and shingle distortion and scuff marks.
Chapter 18—Roof Care and Maintenance provides guidelines for homeowner maintenance. ARMA recommends homeowners inspect their roofs annually to evaluate a roof's general condition and detect any potential leakage problems before they develop. Also, homeowners periodically should clean roof surfaces and gutters of fallen leaves and other debris and keep branches and vines trimmed from the roof to prevent scuffing and algae and fungus growth.
Closing thoughts
ARMA's manual provides a consensus opinion among ARMA-member manufacturers of good practices relating to the use of asphalt roofing products in residential situations. However, still consult manufacturers' printed installation instructions because they may vary from ARMA's recommendations.
ARMA's Asphalt Roofing Residential Manual is available from NRCA's InfoExpress by accessing shop.nrca.net.
Mark S. Graham is NRCA's associate executive director of technical services.
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