Vapor Barrier questions from a newbie

[duncanshannon]

Hi-

I'm taking on a few projects to start 'practicing' for building a cabin some day (Uinversal 20x30) and to improve my 'handiness' overall.

The project at hand is to finish the interior portion of some windows I had installed late last fall.  The exterior work has been done since fall and I need to 1) just trim in some areas where it was a simple replacement (i think) and 2) in some areas where there are new windows, need to add VB and some insulation/sheet rock (i think).

A) On the strict replacement windows (where windows were measured to fit in the RO), i've already put in Window Great Stuff. Next step to trim the windows right and be done with it?  Biggest distances between the existing sheet rock and window jamb is prob. 1", on average more like 1/2" in.

b) this is where I am less certain... In one picture, I have a window in a new place - before it was a solid wall.  Do I just put vapor barier over the whole thing, cut out the window and then put on the 3/4" foil backed insulation followed by 1/2" sheetrock?  (my house has 3/4 foil backed insulation and 1/2" sheet rock on the inside walls).  Question is really what are the details about getting the vapor barier right? Am I trying to create a tight seal to keep or just provide some membrane/some protection by putting in the plastic? ie, am I concerned about putting holes in it with the stapler? What about the seems / edges of where the VB is? Should it tuck in or behind the existing sheet rock? How about wrap out a bit towards the interior of the room?



c) This window was shorter than the orig. RO and thus just got filled in a bit with some 2x and a bit of ply. Still same application of VB over this? You can see I already have VB tacked up on this window. How'd I do? Ready for the foil backed insulation and sheet rock?

[rocking23nf]

vapour barrier to all edges, and taped with tuck tape.

beware, tuck tape is really really expensive.

[rocking23nf]

http://countryplans.com/smf/index.php?topic=8958.0

check my window shot in the second last image.

[duncanshannon]

great shot, thats pretty clear.

if you look at my photos, you will see we cut thru the sheet rock and existing vapor barier at the same spot (so there is no vapor barier sticking out beyond the sheet rock).

given that, what do i tape the vapor barrier too?  the edge of the rock? do i need to cut more rock back while not cutting the vapor barier so that i can tape VB to VB?

[rocking23nf]

it should be a continous barrier, so yes cut back the drywall.

Would i do this? probably not for a cabin.  Depends on how much work it would be, plus the cost of the barrier which i have only seen sold in large rolls