Vinyl Siding Angled J Channel

[matt_i]

All

Need help with a vinyl siding detail. Have a 6:12 roof that is going to meet perpendicular against the flat side of another existing building. So, I will have 2 sloped pieces of J-c

I am drawing a blank on what to do with the bottom end of the J-channel at the bottom end as it transitions back to the normal siding. It can't just be cutoff where the siding goes back to vertical since some of the water will then run behind the siding. Its almost like the J-channel has to have a closed end with a notch in the front/lower part of the "J" to force the water out. I suppose I could notch and bend the J-down vertical but still nothing to keep the momentum of water from spilling behind the rest of the siding.

I'm probably overthinking but haven't had to make up this detail on my own before. Read several siding "manuals" but didn't really come away with a solid answer. Any pics or web images would be helpful.

Thanks in advance.

 

[bczygan]

Rule of thumb is to mechanically prevent water intrusion and use sealants as backup.

Use pieces of ice and water shield, under and over things as required. Use metal flashings and counter flashings where needed.

Can you draw what you are talking about?

Bill

 

[matt_i]

Here are a couple ideas of the detail and the obviously wrong way to do it.

 

[sands35]

Two different answers depending on if the J dumps right into a gutter (or onto a flat roof as the vertical wall turns 90*) or if the vertical wall extends past the bottom end of the J.

Basic rule for siding - go bottom up. Same applied to roofing.

A) Into a gutter / onto roof
I presume there will be a corner molding on the vertical wall. If so, then just cut if off and ensure that it will drain under the corner vinyl molding. Take care so it visually lines up with the corner molding. The key with this is to ensure you have all the layers of corner and step flashing to integrate the corner of the walls above the roof. Slight variation in the methods and layer count, but it is at least 3-4 with metal flashing and rubber flashing tape.

B) With the outside wall extends past the bottom end of the J
Cut a small slit in the siding on the wall so the J will poke out an inch or so from the siding. Depending on where the laps on the siding are, rather than a slit, you can just have multiple layers of siding to allow water to exit the J cleanly onto the outside of the siding. The entire J needs to see daylight at the bottom. You will also want to have a kick out just down hill from the end of J to ensure water exist the bottom of the J and the step flashing on the roof and doesn't go back into the wall. The kickout needs to be entirely behind the J on the wall side.

Google:
Step Flashing
Kick out flashing

There are decent manuals for the manufacturers of vinyl siding at the big box stores.

 

[sands35]

Here are a couple ideas of the detail and the obviously wrong way to do it.

Those are going to be a problem in ~5 years. Water is going to go right down the inside of the siding. There should be a kick out to direct water away from the wall below the end of the J.

 

[rslaback]

I think what you are talking about is how to do a kick out flashing. On the top method the metal pushes the water back out from behind the siding. On the second, you keep your j low enough that it spill into the step flashing kick out. It isn't shown well but at the end of the run you would cut out a square in the bottom so it drops the water.

https://bloggerbuilt.wordpress.com/2012/11/04/kickout-flashing/

 

[matt_i]

Google:
Step Flashing
Kick out flashing

Excellent! Thanks. It all makes sense now, just did not have the right terminology