A tree struck my house today, and I need to replace a vinyl outside corner post. Piece o' cake.

However, I am really confused at my search results for 6" wide siding corner posts. They don't seem to exist. Am I measuring this incorrectly? I don't even see any discontinued products of this dimension, which seems to be unlikely. My house was built in 2006, and is highly generic in nearly every way, so I'm surprised at this. I'm measuring from the corner...to the edge. I can't imagine there's some cryptic industry-insider way of measuring this...

Look at the pic and help me figure out what to do before it rains!

Also, it crossed my mind to replace it with an easily-found next size down, but if I'm not mistake, I would have to replace the j-channels and all the vinyl siding panels that abut to this corner (right?).

corner post

  • I found plenty of 5x5 at big orange. But yours really looks like 6. Sep 16, 2022 at 4:46
  • Yeah I'll ask the folks at big blue tomorrow. But I'm not hopeful. Maybe patches will have to do until spring Sep 16, 2022 at 5:14
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    Messuring what ? how about sharing your measurement with us. What is the total oustide dimension. What is the inside dimension. What is the size of those corner profiles..
    – Traveler
    Sep 16, 2022 at 5:52
  • Skip the big-box stores - they sell a couple of items that are the biggest sellers. Take the corner piece off and take it to a local building supply place. They'll be able to ID it for you and if they don't have it in stock they'll order it. If it happens to no longer be made, they'll get you something that's really close.
    – FreeMan
    Sep 16, 2022 at 10:57

1 Answer 1


Parts like this aren't sold by size. They're simply proprietary to a brand of siding. Find yours, if possible.

Also, the critical dimension is from the face of framing (sheathing) to the inside of the siding channel, in case you need a compatible brand. The face you're measuring here, while of cosmetic concern, isn't what matters with regard to fitment. Protrusion and lap can vary, making the outside dimension somewhat irrelevant.

enter image description here

In short, the corner needs to fit the ends of the siding, or you'd need to cut the siding back accordingly. In either case, it's critical that you leave a gap for expansion.


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