Residential low slope roofing can generally be divided up into two broad categories.
Low slope roof eave detail.
Lay a starter strip apx.
The panels have been designed for application over a wide variety of substrates on roof slopes as low as 1 2 12 pitch.
Then apply standard asphalt shingles over the membrane.
Steep to low slope transitions need membrane that runs 12 14 inches up the steep roof.
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.
These panels generally come with a painted mill finish or a clear acrylic finish.
Finding the right products for your low slope roof.
1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products.
Lay the base sheet down and lap onto the fascia.
If the upper edge of a low slope shed roof intersects a vertical wall the most logical approach in my opinion is to detail the roof as an unvented roof.
Available in 12 16 and 18 widths tite loc and tite loc plus panels can be produced in 22 and 24 gauge steel or 032 and 040 aluminum.
Ice and water grace extending onto the fascia a couple to a few inches.
Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12.
Another approach is to build a cupola or ventilated doghouse in the middle of the low slope roof an approach championed by joe lstiburek.
Page 15 ventilation details ventilation guidelines download pdf page 16 ventilation details ridge vents low slope 6 12 or less steep slope 8 12 or greater severe climate areas tips download pdf page 17 specialty roof deck details wood deck tips download pdf page 18 specialty roof deck details rigid insulation.
Ice and water shield.
For a low slope residential roof there are two main options.
Self adhesive flashing membrane under the shingles prevents leakage on low slope roofs.
Typically large footprint single story warehouses and pre engineered metal buildings will utilize low slope metal roof systems.
Or run the epdm membrane up the roof and keep shingles off the bottom portion.
Low slope metal roofs require less material which reduces the overall load on the building s structure.
Minimum metal roof slope depends on the roof profile building design climate and site location.
Many local building codes require ice and water shield and national building code states ice and water shield must start at the roofs eave edge and extend 2 ft inside heated wall space of a structure.
Larger flat roofed applications low slope such as residential condominium complexes row homes and town houses and smaller applications such as residential porch and garage transitions from the main home where the slope of the roof changes dramatically from steep slope to low slope on the same structure.
Roofing ice and water shield is a critically component to any new roofing system especially in cold weather climates.
