Alternative Construction Research Guide - GCCDS

ShinglesOverview: Shingles are small, easily handled unitsinstalled in overlapping layers to create a water barrier.Roofing shingles can be made of many materials: asphalt,wood, concrete, slate, rubber. Of these, asphalt is the mostcommon, especially for residential construction.Asphalt shingles are easy to install and repair, and arerelatively inexpensive, although prices can vary with quality.They are also available in a variety of colors, styles,and textures, from a basic flat “three-tab” style to a morevariegated “architectural” shingle. 7 Asphalt shingles oftencome with 15-year warranties, but can fail sooner. Higherquality shingles with longer life spans are available andpreferable.There are drawbacks to asphalt shingles. Inexpensive,low-quality shingles can blow off in high winds, and darkasphalt absorbs a great deal of heat, increasing energycosts.If using asphalt shingles in the Gulf Coast region, homeownersshould use a hurricane-resistant asphalt shinglewith a longer lifespan, and install a radiant barrier to counteractthe high heat absorption.Shingles | 8.2lowest roof edge and working up. Rows are chalked ormarked on the roofing felt to facilitate parallel alignmentand proper overlap.Asphalt valley liners should be installed prior to shingling,and asphalt ridge caps should be nailed to any ridges afterall shingles are in place. Nails are applied at the top ofeach shingle, which is covered by the next row, reducingleaks.Speed of Construction: Even relatively inexperiencedroofers can install asphalt shingles quickly. A 1,000square foot house should take no more than a few dayswith a small crew of workers.Delivery Method: Boxes of shingles and rolls of roofingfelt are purchased and delivered from any buildingsupply company. Higher quality or unusual styles may bespecial ordered.Required Equipment: A nail gun increases the speedof installation but is not required. Galvanized Roofing nailsshould be used to attach the shingles to the roof.Specialized Labor: Care should be taken with flashingdetails and proper valley detailing, but no particularspecialized labor is required.PERFORMANCEWind Load: Shingles may blow off in high winds orbe damaged by wind-borne debris. Special high-windresistantasphalt shingles are available and recommendedin coastal hurricane zones.Water Resistance: When properly overlapped andinstalled, shingles should not leak, although their life spanis relatively short and failure in valleys is more common.Mildew and mold may grow on shingles on north-facingor shaded faces of the roof.INSTALLATIONConstruction Process: Asphalt shingles, like allshingles, are only appropriate for roof slopes of 3:12 orsteeper. They require very little preparation for installation.To prepare a roof, the roof sheathing is nailed intoplace and then covered with an underlayment such as30 pound roofing felt. Around the edges of the roof andat valleys, an ice and water shield is laid in lieu of felt forgreater moisture resistance, as well as to strengthen theroof surface at its edges. Eave and gable flashing shouldbe installed before laying out shingles.Strips of asphalt shingles are laid in rows, beginning at the(Fig. 8) A roofing installer nails down strips of asphalt shingles.