BLOCK	R-VALUE	U-VALUE
4" Type I	1.29	.78
4" Type IV	3.37	.30
6" Type I	1.41	.71
6" Type IV	5.92	.17
8" Type IRF	1.61	.62
8" Type IVRF	6.12	.16
12" Type IVRF	6.49	.15
See NCMA TEK 6-2A for more information