Replies

1. 
   Scott | Jan 19, 2010 10:21pm | #1

   I don't know much about your
   I don't know much about your house design, but with proper flashing, trim, caulk, and roof overhangs you shouldn't need to worry much about leaving an air space for drainage.

   I would fill the void with foam, but be sure to use the low-expanding stuff made for windows and doors so you don't over-stress the frame.

1. 
   KenLewie | Jan 19, 2010 10:48pm | #2

   Well here goes, 2 foot overhangs, windows are Marvin Integrity Low EII Argon, tyvec wrap, sloped cedar sill covered with protecto wrap and bathtubed up the RO jamb sides, silliconed in window, protecto wrap on sides overlaping sill, aluminum drip cap siliconed to wall and window, protecto wrap overlaping drip cap and side protecto wrap, tyvec overlaping header protecto wrap, taped tyvek seams. I may use a rain screen under the siding as well. On the inside of 2x6 wall... I used 2x4's to rough in the windows so that I could wrap the 2x6 jambs of the window in 1 1/2" of foamboard. I also added 2x3 perlins on edge so that my wall is 5 1/2 + 2 1/2" = 8" thick. The jambs are 6 9/16" thick. So I spray foam in the 1/2" wide space around the jamb then slide 1 1/2" thich foam cut to be flush with the 8" wall around the jambs. Then add my jamb extensions. This compleetly surrounds the window with foam instead of wood which is not a very good insulator. I know it's a rediculous amount of work but I'm only doing it once.

1. 
   Scott | Jan 20, 2010 12:20am | #3

   >>>I know it's a rediculous
   >>>I know it's a rediculous amount of work but I'm only doing it once.

   Nope, not ridiculous. It's your house and it sounds like you're focused on doing it right.

   I like the 2' overhangs. It's something that I've always wondered why so many houses lack. Overhangs cost relatively little to add, and the protection they offer is WAY worth it IMO.

1. 
   KenLewie | Jan 20, 2010 12:52am | #4

   Thanks for the encouragement Scott... I agree with the 2' overhangs as well... not a big deal to do and if you adjust your window heights properly with the eve's you can get great benifits with regard to shading the sills in the summer and having full sunlight in the winter.

2. 
   davidmeiland | Jan 20, 2010 10:16am | #5

   >>>I would fill the void with foam

   Even at the bottom?

1. 
   DanH | Jan 20, 2010 02:21pm | #6

   There's a couple of good
   There's a couple of good jokes there, but they'd likely be taken the wrong way.

1. 
   KenLewie | Jan 21, 2010 10:45am | #7

   I wouldn't fill the sill as
   I wouldn't fill the sill as that is definantly where the water would be... I called Marvin and asked them... they said to use backer rod and place it up to where the fiberglass casing starts then fill the interior of that with foam. That way if the window caseing ever does leak it will drain to the outside and you still get the maximum amount of sealing. Since they are the ones warranteing my windows I will go with that. Thanks for all the help everyone and also thanks for laying off the obvious jokes concerning voids, bottoms, and foam!