Click on colorful terms to see a picture. Some terms, such as various methods, will not have pictures.
Ice Dam: Condition formed at the lower roof edge by the thawing and refreezing of melted snow on the overhang. Can force water up and under shingles, causing leaks.
Interlocking Shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.
Joist: Any of the small timbers, metal or wood beams arranged parallel from wall to wall to support a floor, ceiling, or roof of a building.
“L” Flashing: Continuous metal flashing consisting of several feet of metal. Used at horizontal walls, bent to resemble an “L”.
Laminated Shingles: Strip shingles containing more than one layer of tabs to create extra thickness. Also called dimensional or architectural shingles.
Lap: To cover the surface of one shingle or roll with another.
Lap Cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.
Louver: A slanted opening for ventilation.
Low-Slope Application: Method of installing asphalt shingles on roof slopes between two and four inches per foot.
Low Slopes: Roof pitches less than 4:12 are considered low sloped roofs. Special installation practices must be used on roofs sloped 2:12 – 4:12. Shingles cannot be installed at slopes less than 2:12.