Irc 2009 Minimum Roof Pitch

The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

Irc 2009 minimum roof pitch.

Built up roofs shall have a design slope of a minimum of one fourth unit vertical in 12 units horizontal 2 percent slope for drainage except for coal tar built up roofs which shall have a design slope of a minimum one eighth unit vertical in 12 units horizontal 1 percent slope. The irc section r902 1 requires class a b or c fire resistant roofing only in jurisdictions designated by law or where the edge of the roof is less than 3 feet from the property line. The 2009 irc has something to say about roof materials and their slopes. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

A good rule of thumb is that a roof slope of 5 12 doesn t have any additional requirements. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions. Asphalt shingles continue to be the most widely installed roof covering option in north america. January 2009 code for residential buildings that creates minimum regulations for one and two family dwellings of three stories or less.

This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit. What is the minimum slope for an asphalt shingle roof. It brings together all building plumbing mechanical fuel gas energy and electrical provisions for one and two family residences. The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope.

Jurisdictions in the us do not commonly require fire resistance classifications for roof coverings on one and two family residential dwellings. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. For the actual language in the model 2018 international residential code this link will take you to section r905 requirements for roof coverings. Get to 4 12 or below on some materials and the cost of the roof can go up due to additional underlayment requirements.

Minimum roof slope roof pitch r905 15 1 liquid applied roofing must have a design roof slope of 1 4 12 or greater 2 slope. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. As a very general rule a steeper roof will perform better and last longer than a roof with a lower slope.