I'm in the process of installing new windows in a house whose old windows did not have a nail flange, so I'll need to cover the nail flange of the new windows. Now, I could do some 1x3 trim around the windows, but I like the "no window trim" look, and see this as an excuse to put an additional layer of "siding" on the house. The question is, is it O.K. to put another layer of water-tight wood over the existing exterior? My house was a kit that it probably 30 years old, is post and beam, and has an exterior that is made up of vertical T&G car decking. (Real 2" x 7 1/2" planks) There is no house wrap in any of the walls I've opened so far, so air infiltration is likely where the T&G isn't airtight.
I'd like to use cedar T1-11 on a 45 degree angle for my siding, with Tyvek underneath. I know that T1-11 isn't highly regarded, but a house across town has it on an angle and you'd never guess it was T1-11. It looks like expensive cedar siding.
Oh, and can Tyvek be pushed into the valleys of the T&G, or is it supposed to be pulled tight?