Calculations based on owens corning optiliner system.
R30 roof assembly.
Please note that the r values for roof membranes shingles tiles air films and roof deck materials might or might not be permitted by your local code to be included when total roof assembly r value is being calculated for the purpose of satisfying energy code requirements.
R value of various materials.
Because roof purlins vary in size the thickness and r value of the insulation will fluctuate accordingly.
The directory of roof assemblies dora is a web application database of roof systems tested in accordance with standards referenced in chapter 15 of the international building code ibc.
Calculation based on standing seam roof ssr system table 4 wall assembly u factors thermal break cavity insulation wall u factor1 none r16 mbi 0 074 none r19 mbi 0 066 1 8 foam r25 mbi 0 057 1 8 foam r30 mbi 0 049 certifi ed r13 r30 mbi 0 042 1.
Cathedral ceilings built with 2x12 rafters have space for standard r 30 batts and ventilation.
Calculating the r value of a roof assembly with different materials is usually as simple as adding together the r values of the individual layers.
Always check with your local code authority.
R 19 and r 30 roof insulation insulation blankets can be used between the roof purlins without the need of a framed ceiling.
A recent mckinsey co.
You should of course.
8 girts spaced 5.
Cathedral ceilings must provide space between the roof deck and ceiling for adequate insulation and ventilation.
Improved insulation is a good step toward improving building efficiency particularly since the atlanta based american society of heating refrigerating and air conditioning engineers ashrae increased minimum roof insulation levels in 2007 in its standard 90 1 the first increase in 18 years and if that isn t enough to spur someone into action.
Assemblies may be easily searched viewed saved and printed.
This service lists wind uplift load capacity on single ply and modified bitumen roof systems.
A vent baffle should be installed between the insulation and roof decking to ensure that the ventilation channel is maintained.
Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.
Owens corning r 30 ecotouch pink cathedral ceiling kraft faced fiberglass insulation batt 23 3 4 in.