Minimum R Value For Roof Insulation Ontario

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.

Minimum r value for roof insulation ontario.

Minimum insulation r value requirements non residential above roof deck. For a very good introductory overview article on r value see r values over at the website of. The recommended r value for attic insulation in ontario is between r 50 and r 60. It means that different products require different densities to deliver the same r value.

Existing 3 4 inches of insulation. Know exactly how much you need with our project calculators. Insulation r value is proportional to the insulating material being used. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.

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. 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. R value of various materials. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

When determining how much insulation you need don t guesstimate calculate. 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. The revised lttr values are as follows. Recommended insulation levels for retrofitting existing wood framed buildings.

The updated lttr test methods will result in lower lttr values than previously published. The ontario building code requirements for insulation is only one of many sections within the act that helps protect you and other people. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. The r value of the insulation for every inch of thickness depends on the type of insulation.

Thickness inches new lttr values per inch thickness new lttr values per thickness 1 5 6 5 6. Add insulation to attic. R value measures how well certain building insulation materials can resist heat. Pima has established that polyiso roof insulation will have different minimum r values depending on board thickness.

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.