# Vinyl siding junction at windows' built in J channels



## Tom Struble (Dec 29, 2008)

i can't think of a way with windows with a built in J channel,the top lock/nailfin on vinyl siding is also the drainage leg, you could use pieces of zip tape on courses just under the window to divert water directly on to the top lock...this is sort of a jury rig thing

i'd be more concerned that you have kick out diverters installed at any roof abutments


vinyl siding is very good with regards to water drainage


----------



## loneframer (Mar 27, 2009)

Water will get behind the siding at the bottom of the J, you need to get it back out. This is how I do it. The flashing is actually behind the windows nailing flange as well. This will work with built in J also. You need to address the top nailing flange just as importantly, as any condensation behind the siding may find it's way behind that flange. Caulking the window flanges before installation is a start. Taping the flange with Zip tape is a second line of defense.

The biggest downside to the Zip system is the difficulty in flashing wall penetrations properly, IMO.


----------



## Tom Struble (Dec 29, 2008)

there is no J channel,the window flange is taped with zip tape,that method does and can not not apply without modifying the window flashing detail that Huber supplies...not sure i would do that

zip wall needs no special treatment around the window openings other than the specified taping details,let the product do what it's supposed to


----------



## loneframer (Mar 27, 2009)

Tom Struble said:


> zip wall needs no special treatment around the window openings other than the specified taping details,let the product do what it's supposed to


I don't like the idea of depending on a taped joint to resist water infiltration.

I've used the zip system on a roof, but not walls. I'm curious how that tape holds after 15-20 years behind siding.


----------



## kwikfishron (Mar 11, 2010)

Tom Struble said:


> there is no J channel,the window flange is taped with zip tape,that method does and can not not apply without modifying the window flashing detail that Huber supplies...not sure i would do that


The bottom flange is not taped in the zip window install details so Lones flashing detail will work fine if you didn’t tape the windows until the siding is installed.



loneframer said:


> I don't like the idea of depending on a taped joint to resist water infiltration.
> 
> I've used the zip system on a roof, but not walls. I'm curious how that tape holds after 15-20 years behind siding.


The warranty on the tape is only 15 years. It would seem to me that installing vinyl siding over zip could be a long term recipe for disaster.


----------



## Arky217 (Aug 18, 2010)

loneframer said:


> I don't like the idea of depending on a taped joint to resist water infiltration.
> 
> I've used the zip system on a roof, but not walls. I'm curious how that tape holds after 15-20 years behind siding.



I don't know about 15-20 years, but the Zip tape has held up well on both the roof and walls for 6 months. (Just now finished covering the roof). In fact, I had Zip tape across the peak and when I cut out for the ridge vent, the Zip tape was still tightly adhered to the roof panels. So, I think that it will hold up for as long as I need it to (I'm 66  ).

That said, I like your method, Longframer, and think that I will use a piece of aluminum flashing at the corners as in your pic.
I think that even a 6" wide piece at each corner would probably divert most of the water onto the outside of the next lower course of siding.
I'll just slip it under the bottom nailing fin and over the nailing flange of the next lower course, as in your pic.

As to the top window nailing fin, it's Zip tape flashed, but also it's about the level as the bottom of the facia board on the 2' overhang, so I don't think any water will ever get up there.

Thanks for the replies,
Arky


----------



## Tom Struble (Dec 29, 2008)

kwikfishron said:


> The bottom flange is not taped in the zip window install details so Lones flashing detail will work fine if you didn’t tape the windows until the siding is installed.
> .



what seals the top of the flashing?just the window flange?now maybe a skirt installed with the sill flashing tape over the top which is a [better detail]would be the way to go,but unless spelled out or approved by Huber i wouldn't recommend it.don't try to re engineer an engineered system imo

go to one of the zipwall seminars that many lumbers yards host,these wall panels are more plastic than wood,good? bad? idk but defiantly a product that needs careful attention to manu.recomendations


plus were talking vinyl siding here,like i said a product that drains well already


op really should be asking zipwall these questions


----------



## loneframer (Mar 27, 2009)

IMO, the flashing behind the bottom nailing flange is nothing more than an extension of the nailing flange. I see no downside to extending the flange to lap onto the siding hem. If not with metal, then with PVC coil. I don't mind allowing the zip system to deal with minor water intrusion, but channels are just that, channels, that channel water from the top of window to the sides of window and eventually behind the siding. The 6" tabs will do the same job, but I prefer going the full width, during window installation, then trim the flashing to the siding lock during siding installation.

The flashing does the same thing as a kick-out at the fascia line, gets the water away from the wall and back to daylight. Job 1 in my opinion, regardless of zip walls specs.


----------



## kwikfishron (Mar 11, 2010)

Tom Struble said:


> what seals the top of the flashing?just the window flange?now maybe a skirt installed with the sill flashing tape over the top which is a [better detail]would be the way to go,but unless spelled out or approved by Huber i wouldn't recommend it.don't try to re engineer an engineered system imo
> 
> go to one of the zipwall seminars that many lumbers yards host,these wall panels are more plastic than wood,good? bad? idk but defiantly a product that needs careful attention to manu.recomendations
> 
> ...


Who’s trying to reengineer anything? Huber shows no tape on the bottom flange. Why wouldn’t you flash under the flange and over the panel like in the Lone pic.

http://www.zipsystem.com/uploads/resources/files/HUB313_Wall Installation_sm-02242011014950.pdf

And yes I agree vinyl siding drains very well and it also allows water in like no other product I know. 

I have visions of years of water trickling down the wall starting from as high as the soffits encountering the top edge of all of the tape seams. 

I can’t imagine the tape out lasting the intended life of the siding but that’s just my opinion.


----------



## loneframer (Mar 27, 2009)

Interesting how their flanged window instructions provide a zip tape pan under the window unit. That's there to protect the framing from moisture.

If that is the case, why wouldn't you install the metal flashing before the pan, thereby diverting any water caught by the sill pan to the outside of the siding?

This is especially important on homes with windows on the second floor that stack over windows or doors on the first floor.

IMO, that tape will fail at some point in time, be it 5 years or 25 years. I vote for an insurance plan.


----------



## woodworkbykirk (Sep 25, 2011)

i dont tape i use vycor or bluskin... im not sure what "ziptape" is, is it the same as tuck tape? if so in alberta tuck tape was banned by the alberta siding association a few years ago for the main reason that it was being used incorrectly by too many installers not to mention the glue fails after 2 years in a sub zero environment


----------



## kwikfishron (Mar 11, 2010)

wooworkbykirk said:


> i dont tape i use vycor or bluskin... im not sure what "ziptape" is, is it the same as tuck tape? if so in alberta tuck tape was banned by the alberta siding association a few years ago for the main reason that it was being used incorrectly by too many installers not to mention the glue fails after 2 years in a sub zero environment


We're talking about the "Zip System" Kirk. http://huberwood.com/main.aspx?pagename=zipsystemwalloverview


----------



## woodworkbykirk (Sep 25, 2011)

ahh ok, i know what it is now. ive seen it in finehomebuilding magazine. this is a product that isnt available here yet. at the rate we get things it will be another 5 years or so... it only took nearly 2 years to get the latest paslode impulse framing gun in stores... i feel a certain picture of a collection coming on ... hey riz:whistling2:


----------



## MJW (Feb 7, 2006)

Does this product breathe like Tyvek or felt is supposed to? Or is it similar to OSB in sealing up the wall cavity?


We flash like Loneframer, but I wear a shirt and don't wear a necklace.


----------



## Tom Struble (Dec 29, 2008)

MJW said:


> We flash like Loneframer



with all due respect that detail is reverse lapped,installing it under the flange but over the zip tape sill flashing is still reverse lapped and that my friends can bite you


----------



## loneframer (Mar 27, 2009)

Tom Struble said:


> with all due respect that detail is reverse lapped,installing it under the flange but over the zip tape sill flashing is still reverse lapped and that my friends can bite you


My window didn't have a zip tape sill pan. If it did, the flashing would have gone on before the zip tape.


Technically though, they want the zip tape sill pan to lap onto the zip wall with no flashing at the bottom flange and nothing to keep water from staying behind the siding.
At which point, the flashing in front of the Zip Tape is nothing more than a window flange extension and has nothing to do with the manufacturers specs on the zip wall. The product is installed as recommended by Zip-Wall.

When the head flange tape gives way and leaks water down to the zip tape pan, the pan will do exactly as it was intended and divert the water back out BEHIND the siding, where Zip-Wall prefers it, apparently.

However, the water that flows over the head tape, down the sides of the window and onto the aluminum flashing will be diverted to where I want it, to daylight.


----------

