Table A102.2.5

Default U-factors for Metal Building Roofs

			Overall U-Factor for Assembly of Base Roof Plus Continuous Insulation (uninterrupted by framing) Rated R-Value of Continuous Insulation
Insulation System	Rated R-Value of Insulation	Overall U-Factor for Entire Base Roof Assembly	R-6.5	R-13	R-19.5	R-26	R-32.5	R-39
Standing Seam Roofs with Thermal Spacer Blocksa, b
	None	1.280	0.137	0.073	0.049	0.037	0.030	0.025
	R-10	0.115	0.066	0.046	0.035	0.029	0.024	0.021
Single	R-11	0.107	0.063	0.045	0.035	0.028	0.024	0.021
Layer	R-13	0.101	0.061	0.044	0.034	0.028	0.024	0.020
	R-16	0.096	0.059	0.043	0.033	0.027	0.023	0.020
	R-19	0.082	0.053	0.040	0.031	0.026	0.022	0.020
	R-10 + R-10	0.088	0.056	0.041	0.032	0.027	0.023	0.020
	R-10 + R-11	0.086	0.055	0.041	0.032	0.027	0.023	0.020
	R-11 + R-11	0.085	0.055	0.040	0.032	0.026	0.023	0.020
	R-10 + R-13	0.084	0.054	0.040	0.032	0.026	0.023	0.020
Double	R-11 + R-13	0.082	0.053	0.040	0.032	0.026	0.022	0.020
Layer	R-13 + R-13	0.075	0.050	0.038	0.030	0.025	0.022	0.019
	R-10 + R-19	0.074	0.050	0.038	0.030	0.025	0.022	0.019
	R-11 + R-19	0.072	0.049	0.037	0.030	0.025	0.022	0.019
	R-13 + R-19	0.068	0.047	0.036	0.029	0.025	0.021	0.019
	R-16 + R-19	0.065	0.046	0.035	0.029	0.024	0.021	0.018
	R-19 + R-19	0.060	0.043	0.034	0.028	0.023	0.020	0.018
Liner	R-19 + R-11	0.035
System	R-25 + R-11	0.031
	R-30 + R-11	0.029
	R-25 + R-11 + R-11	0.026
Filled Cavity with Thermal Spacer Blocksc
	R-10 + R-19	0.057	0.042	0.033	0.027	0.023	0.020	0.018
Standing Seam Roofs without Thermal Spacer Blocks
Liner System	R-19 + R-11	0.040
Thru-Fastened Roofs without Thermal Spacer Blocks
Single	R-10	0.184
Layer	R-11	0.182
	R-13	0.174
	R-16	0.157
	R-19	0.151
Liner System	R-19 + R-11	0.044

	(Multiple R-values are listed in order from inside to outside)
a	A standing seam roof clip that provides a minimum 1.5 inch distance between the top of the purlins and the underside of the metal roof panels is required.
b	A minimum R-3 thermal spacer block is required.
c	A minimum R-5 thermal spacer block is required.