Low Slope Roof Section

The only function the three tab shingles perform at that low a slope is decorative that s a legitimate use of shingles when you wish to preserve a consistent appearance but they do not function as a weather barrier in such installations that function is being performed it s being performed at all by the underlayment and or flashing below the shingles which in this case must be a material with self sealing properties to prevent water intrusion at the shingle s fasteners.

Low slope roof section.

By low slope roofing we mean any roof that is pitched at less than 4 inches of rise in 12 inches of run or 4 12 pitch. For buildings with low slope roofs less than 2 12 slope the wind speed at eave height is used. The reason water ponds on a low slope roof is a possible misinterpretation of the 1 4 in 12 minimum slope by the building code. Low slope structural roofing generally used on roof pitches ranging from 12 to 3 12 consists of interlocking panels commonly called standing seam roofing that run vertically along the roof surface.

1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products. Roof fast 95 base iko roof fast 95 base is a self adhesive product that can easily be cold applied on low slope roofs. Regular asphalt shingles and standard skylights will work at pitches of 4 12 or greater but at lower pitches you have to use different materials. For a low slope residential roof there are two main options.

For anything less than that you should use a roofing material specifically made for low slope roofs. Low slope roofs present special challenges in terms of preventing unique types of damage. Some building codes allow as low as a 2 slope with asphalt shingles if additional steps are taken. Significant insight may be found in asce 7 section 8 4 as referenced in ibc section 1611 2.

The usual slope for asphalt shingles is a 4 or greater rise for every horizontal foot of run. Then apply standard asphalt shingles over the membrane. 1 3 5 design pressure coefficients for roof zones wind produces different magnitudes of pressure acting on the surfaces of a building due to the building s geometry and can create small areas of higher pressure on a surface while at the same time other areas on the same surface experience lower pressures. Vertical end laps should be at least 3 inches and horizontal laps 6 inches.

These panels generally come with a painted mill finish or a clear acrylic finish. In areas with extensive snowfall or windblown rain the best protection against leakage is to cover the entire low slope roof area with a bituminous membrane as shown in figure 2 4. Iko roof fast low slope roofing components are engineered and manufactured to meet those particular challenges. The membrane will outlast the shingles and seal around all nail penetrations.