The irc regulates work on one and two family dwellings and townhouses.
Irc 2015 roof underlayment.
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.
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.
Peters has adopted the 2015 international residential code irc with amendments.
Roof slopes between 2 and 12 and up to 4 in 12 require double underlayment as detailed in table 905 1 1 2.
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.
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.
You may be looking for the quick roofing guide to the international building code.
This page references the 2018 international residential code.
Roofing underlayment or felt helps prevent unevenness in the roof sheathing from telegraphing through the shingles.
Last updated july 13 2020.
Fifteen pound or heavier felt underlayment is required by code in some areas.
Quick roofing guide to the international residential code.
The city made one amendment to irc chapter 9 sections r905 2 8 2 valleys.
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.
Roofing underlayment or felt is usually required for the ul fire rating to apply since shingles are usually tested with underlayment.
R905 3 minimum 3 in 12 for metal roof shingles see special installation requirements of manufacturer andirc.
The roof deck should be sound and level before laying the underlayment.
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.
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.
See special installation requirements of manufacturer and irc.
R806 5 unvented attic and unvented enclosed rafter assemblies.
