I AM THINKING ABOUT INSTALLING VINYL SIDEING ON MY 1920 BUILT CAPE COD THAT NOW HAS CEDER SHINGLES.WOULD I WANT TO INSTALL A HOUSE RAP AND THE FOAM BOARD INSULATION.HOW MUCH R VALUE IS ADDED WITH THE RAP AND FOAM BOARD?
THANKS
RICH
CLIFTON SPRINGS NY

It all depends on the foam board you use, most of them I believe are about 3.5R value, but the real benefit will be with the wind you keep out and most of the nooks and crannies will be sealed, older homes have a tendency to leak air pretty good. good luck though