Minimum Roof Insulation Thickness Ibc

Both codes provide specific instructions for re roofing projects and both are clear that replacements must comply with insulation r value requirements if the roof system is part of the building thermal envelope and contains insulation entirely above the deck.

Minimum roof insulation thickness ibc. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. The pitch of your roof is generally determined by the span of the sidewalls and the desired roof height. Aluminum zinc alloy coated steel. Astm b370 minimum 16 oz sq.

For pre formed metal shingle systems. Astm b209 0 024 inch minimum thickness for roll formed panels and 0 019 inch mini mum thickness for press formed shingles. If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used to maintain a consistent total sheathing thickness. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

Base flashing shall be of either corrosion resistant metal of minimum nominal 0 019 inch 0 5 mm thickness or mineral surfaced roll roofing weighing not less than 77 pounds per 100 square feet 4 kg m 2. If your community receives a lot of snow during the winter local building codes may require a minimum roof pitch for snow load which ensures that heavy snows will slide off. Astm a792 az 50. Continuous insulation zones ashrae 90 1 ashrae 189 1 igcc ibc iecc 2004 2007 2010 2013 2016 2009 2011 2014 2012 2015 2009 2012 2015 0 25 1 15 20 2 15 20 25 3 15 20 25 4 15 20 302535 5 15 20 302535 6 15 20 3035 7 15 20 3540 25 8 20 3540 25 minimum r value non residential above roof deck.

Where the roof sheathing is less than 3 4 inch 19 1 mm thick the nails. 2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing. 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. 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.

Specific insulation requirements of section c402 2 thermal requirements of either. High yield copper for metal sheet roof covering systems. Base flashing shall be of either corrosion resistant metal of minimum nominal 0 019 inch 0 483 mm thickness or mineral surfaced roll roofing weighing not less than 77 pounds per 100 square feet 3 76 kg m 2.