Irc 2015 Roof Underlayment

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 2015 roof underlayment.

The city of st. R905 3 minimum 3 in 12 for metal roof shingles see special installation requirements of manufacturer andirc. The code requirements for re covering or replacing an existing roof covering can be found in irc section r908 reroofing. R806 5 unvented attic and unvented enclosed rafter assemblies.

Quick roofing guide to the international residential code. Fifteen pound or heavier felt underlayment is required by code in some areas. You may be looking for the quick roofing guide to the international building code. 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.

The city made one amendment to irc chapter 9 sections r905 2 8 2 valleys. This page references the 2018 international residential code. Unvented attics and unvented enclosed roof framing assemblies created by ceilings that are applied directly to the underside of the roof framing members and structural roof sheathing applied directly to the top of the roof framing members rafters shall be permitted where all the following conditions are met. For roof slopes from two units vertical in 12 units horizontal 17 percent slope and up to four units vertical in 12 units horizontal 33 percent slope underlayment shall be two layers applied in the following manner.

See special installation requirements of manufacturer and irc. Roofing underlayment or felt is usually required for the ul fire rating to apply since shingles are usually tested with underlayment. In areas where the average daily temperature in january is 25 f 4 c or less the metal valley flashing underlayment shall be solid cemented to the roofing underlayment for roof slopes under seven units vertical in 12 units horizontal 58 percent slope or self adhering polymer modified bitumen sheet. Roofing underlayment or felt helps prevent unevenness in the roof sheathing from telegraphing through the shingles.

The roof deck should be sound and level before laying the underlayment. Apply a minimum 19 inch wide 483 mm strip of underlayment felt parallel with and starting at the eaves fastened sufficiently to hold in place. 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. Last updated july 13 2020.

In chapter 9 of the 2015 irc the underlayment requirements for steep slope roof coverings are included in three tables material types application and attachment requirements. The irc regulates work on one and two family dwellings and townhouses.