Expert: Fred Lauffer - 7/20/2006

Question
I have new vinyl repacement windows being installed.  The old
windows have been completely removed, and now the rough
opening is down to the studs.  the windows have a sloping brick
sill.  there is an airspace betweeen the framing and the
masonary.  Should the new replacement window frame overlap
the airspace.  Thus haveing the inside edge of the window inside
the framing and the outside edge extending to the brick?

Answer
I think I under the Question It's about the gap behind the brick veneer. I'm sorry about the delay with this answer I THOUGHT I SENT IT OUT  LAST WEEK. IT DIDNOT Fly out to you,, soi'm doing it again. Replacement windows normally are installed from jamb or side trim to the same wood on all four sides. There is normally no exposure of the studs. The windows go trim to trim...The old inside and outer trim are all left in place. Somtimes the outer trim gets covered ,,, which is OK  if it's done well...Now your question.-- The airspace or gap behind the brick is-- very--- very important.The gap is there because bricks always "sweat" with a weather change or the moisture that comes from inside the house >>> Bricks have a high rate of thermal conductivity,, therefore they make a lot of condensation..IT'S very important that this gap is properly sealed from any suorce of outside water... When the windows are installed and if brick gap is exposed it must be closed with any good flashing or trim. Use good treated wood,,alum. or vinyl,, whatever looks good and it tight and waterproof... You may need to do some calking ,,if so,,, use ONLY  ONLY  a good 30-40 year calk,, Do it neatly,. don't slop it all over the brick like some dumbies do...If there is a gap inside between the   window to the studs or any other place inside   fillit with foam or fiberglass..Foam is the best but it is messy,,DONT get it on the windows.. What about covering the stud work. New drywall,plaster,and/trim will be needed.. Treat this matl. with a good waterproofing, then proper paint ,,Primer and oil,, No latex, IF you can put some new sills in like manmade marble or any other good water proof matl.. do it.   I hope this helpful-- Yours FLINSPECT@YAHOO.COM  PS sorry about the delay--- PSS ican't find the spell check ,so please excuse any BOO_BOOs.