I have re-written it as making your new roof 4:12 but you can certainly adapt my calculations to any other roof slope you want. The distance is 14 ft from the existing toe of roof slope to the new outside support band? The total length of the rafters is going to be 18 ft so I may have a good size soffit. How far up the existing roof must I go to achieve this? I only want a 1' to 2' slope overall for the new metal roof. I want to tie into an existing 4 on12 roof with a new roof over a deck. The illustration of roof slope types shown above is provided courtesy of Carson Dunlop Associates, a Toronto Home Inspection and Home Inspection Education firm.īy Carl Ward - where will my new low-slope roof tie into the existing roof See ROOF SLOPE DEFINITIONS for definitions of rise, run, roof slope, pitch, angle, grade. from the ground, the air, from inside the attic, or from on the roof. See ROOF MEASUREMENTS for an explanation of all of the ways to measure roof slope, size, area, etc. If asphalt shingles are to be applied on steep slope roofs or on near-vertical surfaces, special methods are required.

Clearly once we get near 90 ° we're describing a wall, not a roof, that is vertical or near-vertical surface.ģ.

Slopes greater than 18 / 12 are found on A-frame roofs and some Mansard style roofs. If asphalt shingles are to be installed on a low slope roof, special steps are required to avoid short roof life and roof leaks.Ģ. Some sources consider low slope to include 3 / 12 pitch roofs. Low slope roofs are from 0 to 3 / 12 in pitch. needed for installation, inspection, repairġ. Too steep to walk-on, roof-jacks, scaffolding, affixed ladders, etc. Roof Slope Expressed as Rise / Run in Inches Ĭommon Roof Slopes Expressed in Rise/Run and Angle + Slope expressed as Grade The table below describes different roof slopes, giving roof slope in rise/run in inches and re-expressing the same slopes as angle, grade, walk-ability, and roof type or class. The A-frame style roof shown just above, located on Highway 61 just South of Hovland Minnesota, is built at a 75° angle and is considered a very-steep roof. Table of Roof Slopes, Roof Types, Walkability We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need. This article series gives clear examples just about every possible way to figure out any or all roof dimensions and measurements expressing the roof area, width, length, slope, rise, run, and unit rise in inches per foot. This table lists all of the common roof slopes expressed as rise / run, roof angle, roof slope, slope grade, and walk-ability. Roof slope, pitch, rise, run, typw & walkability table: We have no relationship with advertisers, products, or services discussed at this website. InspectAPedia tolerates no conflicts of interest.

Walkable roof panels