# Do I Need To Strap Exterior Walls (Interior Side) Before Drywall?



## chrisBC (Dec 28, 2010)

unless the area you live in does things a lot differently...

no, there is no need for strapping this unless you are up against concrete or a situation similar to that. 

after you insulate VB goes onto wall, then board wall (ceiling first, you may find this is where your insulation is lacking is at the joists, maybe worth to cut the ceiling a couple feet back from the ext. wall.)

if you strap it you will have to bring out your electrical boxes and whatnot, and there is absolutely no need for it from what you are saying...a typical wood frame stud wall.

don't ask the people at big box stores how to do things, 1 in 5 or 10 people working there may actually have an idea what they are doing

hope it goes well..


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## Willie T (Jan 29, 2009)

I just wrote you a long explanation of why moisture barrier is used. But I decided to delete it.

You'll learn a lot more if you do the research for yourself.

Sorry, but you should be comfortable with WHY, and not just WHAT to do. You will only get that by digging for yourself.

Keep looking till you actually understand what insulation and moisture barriers really do in your specific geographic area. You'll sleep better after you do this.


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## Dreams (Sep 25, 2011)

Thanks Chris, Willie, for responding, 

Thanks for taking the time to respond, I really appreciate it :thumbsup:


My intentions were to include the details of my house which should have been there from the start for a more accurate response. Here they are:

Location: Montreal, Quebec
Side Split 
Built: 1979
Exterior covering: Brick
Interior walls (Exterior Side) 2 x 6 studs
R-Value (as per my city codes..i called last week) R-20 is required minimum and i will be inserting R-22 Roxul
Rooms is questions: 2 bedrooms on the highest level of the house (not basement)

Windows are brand new, i had all of them changed last summer, they are top quality windows and have made a huge difference in the rooms, the install was done pretty good as well, well insulated everywhere. 

The walls that are really cold most of the time are the ones that have and don't have windows, so not sure if it was the windows to start.

I would "think" and hope there is Tyvec on the outside after the brick, all new construction around here has it but i don't know what the rules were 30 years ago.

That was what i was thinking reg. electrical outlets, jams, etc after strapping, including the windows, especially the windows, it would look ridiculous if i had to do this and i thought that was sorta odd to have to do that. :confused1:

Willie T,
After the tons and tons of reading, on more places that i can count, I completely understand the function of the vapour barrier, what it does, and why we need it so that part is ok. For this part, i am very good.
It's more the instal of it that has me wondering...is it just the framing that gets covered or does the VB have to connect to everything? I got confused as to how it protects the inside walls from getting moisture when the outside wall and inside wall meet at the 90 degrees / corners? I see how to affix it, staples and acoustical caulking, but they new show the ends or when it meets another wall..only the front for some reason which i find the easiest part. 

It just sorta made sense in a way that the space left between the strapping and the Drywall is used to circulate air and allow it to dry up. It's just when i went to look on the net how accurate this info actually was, i stumbled across the link i posted and it re-inforced what they told me...when i continued to look and see video's, everything showed otherwise HOWEVER i do see that people do this on the ceiling, this tends to me more common??

So, if strapping is not needed (can you please re-confirm based on my details above reg. my house), if i tear down the ceiling, is it needed there?

Thanks again!!
Tony


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## Willie T (Jan 29, 2009)

The reason for stripping the ceiling is two-fold.

One, is to provide closer spacing, and therefore more support, for fastening the ceiling drywall, the "lid".

The second, and most important, is to negate the undulating ceiling surface caused by the varying crowns, sags, and bows of the framing members, be they rafters or trusses. The stripping is "shimmed" or wedged down from the bottoms of the framing members at varying increments, in varying locations, depending upon how much 'leveling' is necessary to give you a perfectly flat ceiling substructure onto which to fasten the drywall sheets.

Of course the stripping, (usually 1x3's on 16 or 12 inch centers running perpendicular to the direction of the framing members) is to be firmly fastened up into the bottoms of the ceiling framing members. Two good, long screws at each juncture is sufficient.


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