Minimum R Value For Roof Insulation Ontario

The updated lttr test methods will result in lower lttr values than previously published.

Minimum r value for roof insulation ontario.

Minimum insulation r value requirements non residential above roof deck. Thickness inches new lttr values per inch thickness new lttr values per thickness 1 5 6 5 6. Know exactly how much you need with our project calculators. R value roofs without attic space insulation above deck u 0 032 r 30 0 ci u 0 028 r 35 0 ci with attic space and other u 0 021 r 50 0 u 0 017 r 60 0 walls above grade above grade walls u 0 055 r 13 0 r 10 0 ci u 0 055 r 13 0 r 10 0 ci wall below grade.

When determining how much insulation you need don t guesstimate calculate. The ontario building code requirements for insulation is only one of many sections within the act that helps protect you and other people. You should of course see the manufacturer provided technical data sheet for the r value of specific products. The ontario building code act is a legal framework set up by the provincial government to establish minimum building standards and it applies to any new builds renovations or change of use construction.

Recommended insulation levels for retrofitting existing wood framed buildings. It means that different products require different densities to deliver the same r value. The recommended r value for attic insulation in ontario is between r 50 and r 60. The r value of the insulation for every inch of thickness depends on the type of insulation.

For a very good introductory overview article on r value see r values over at the website of. R value of various materials. The revised lttr values are as follows. R value measures how well certain building insulation materials can resist heat.

State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30. See the department of energy s doe ranges for recommended levels of insulation below. The higher the r value the greater the insulation performance. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

A bare concrete wall basement foundation rates at an insulation r value of about r 1 newly insulated attic rates at an insulation r value of r 40 or more. Add insulation to attic. Pima has established that polyiso roof insulation will have different minimum r values depending on board thickness. Existing 3 4 inches of insulation.

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.