# Tyvek house wrap behind new T1-11 siding and corners



## XSleeper (Sep 23, 2007)

It looks like you are doing a very nice job. However, it would have been better if you had used a butyl flashing tape (like Tyvek Straightflash) around the windows and around any edges that you would like to seal.

Generally you want the Tyvek to go underneath the bottom and side flanges of the window, then the Straightflash goes over the fin and onto the Tyvek. It holds better than the seam tape does. The seam tape is great for Tyvek to Tyvek. Along edges, I like to leave the Tyvek about 1" short so that you have 1" of clean wood to tape to, then use the Straightflash. 

Tyvek laps over the top nail fin and laps over the top of any roof flashing.


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## BIG Johnson (Apr 9, 2017)

Did you rummage through construction site dumpsters to get that Tyvek?


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## chandler48 (Jun 5, 2017)

One other observation. It appears you have taped your Tyvek over the top of the window frame, as opposed to the nailing flange. That will need to be cut back as Brant said about an inch or so from the flange and window sticky tape applied in the manner you described (bottom, side, top) all around the window flange, exposed wood and onto the Tyvek.


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## XSleeper (Sep 23, 2007)

BIG Johnson said:


> Did you rummage through construction site dumpsters to get that Tyvek?


Looks like the 3ft roll from Home Depot to me.


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## Al11 (Aug 16, 2016)

XSleeper said:


> It looks like you are doing a very nice job. However, it would have been better if you had used a butyl flashing tape (like Tyvek Straightflash) around the windows and around any edges that you would like to seal.
> 
> Generally you want the Tyvek to go underneath the bottom and side flanges of the window, then the Straightflash goes over the fin and onto the Tyvek. It holds better than the seam tape does. The seam tape is great for Tyvek to Tyvek. Along edges, I like to leave the Tyvek about 1" short so that you have 1" of clean wood to tape to, then use the Straightflash.
> 
> Tyvek laps over the top nail fin and laps over the top of any roof flashing.


The aluminum frame windows already had butyl flashings under them and I left it intact. See pictures below.
I purchased the 3 ft rolls from Home Depot.
My main concern is regarding the edges where the siding will meet stucco. I have caulked under the Tyvek wrap (used thick layer of polyurethane caulk). Then I will use a L moulding to cover the siding stucco edge and will again caulk around it. I just hope that is all sufficient.
Also for the flashing on the bottom should the Tyvek wrap go over it or under it.


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## Al11 (Aug 16, 2016)

I also wanted to mention that the windows will be changed out with Vinyl Retrofit Windows that are common in California. I am not sure where in the aluminum framing they will cut to place the windows in but hopefully the flashing will be untouched.


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## XSleeper (Sep 23, 2007)

Could have sworn I answered that.


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## Al11 (Aug 16, 2016)

Al11 said:


> The aluminum frame windows already had butyl flashings under them and I left it intact. See pictures below.
> I purchased the 3 ft rolls from Home Depot.
> My main concern is regarding the edges where the siding will meet stucco. I have caulked under the Tyvek wrap (used thick layer of polyurethane caulk). Then I will use a L moulding to cover the siding stucco edge and will again caulk around it. I just hope that is all sufficient.
> Also for the flashing on the bottom should the Tyvek wrap go over it or under it.


OK. Sorry I missed your last sentence. So as you mentioned: "Tyvek laps over the top nail fin and laps over the top of any roof flashing." 
Great. Then the siding should cover the entire tyvek wrap or is it OK for like half inch of tyvek showing on the bottom of the siding over the roof flashing. Also will in need to be caulked? I would think not.


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## XSleeper (Sep 23, 2007)

You don't usually want to see any housewrap below the siding. No, the bottom of the siding does NOT get caulked. Any moisture on (either in front of or behind) the housewrap needs to be able to find a way to wick out. The siding needs to be kept far enough off the roof to get a paint brush under it to keep it painted. Most mfg's recommend 2" miniumum to roofs.


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## Nealtw (Jun 22, 2017)

I hope you trim the windows with wood as leaving that old crap there while adding everything else new, expect problems to show up in about two years.
The wood trim will make it easier to get to the windows.


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