The way to allow for this expansion is to install the corner post down from the soffit or top of the corner.
How to install outside corners for vinyl siding.
Tuck the bottom piece of siding into the siding flange on the new corner and nail it into place while holding the above siding strip out of the way.
Learn how to install vinyl siding on your home.
Installing vinyl siding can be a diy project with the right tools and know how.
Keep a 1 4 inch gap between the top of the corner post and the soffit.
An assistant is handy at this stage to keep the siding from getting in your way.
Each corner should be hung straight so drop a plumb line for each corner post.
Nail into place through the slots in the post with the nail at the top of the slot.
Expansionwhen the temperature changes vinyl siding expands and contracts.
This video shows how to install certainteed outside corner posts for vinyl siding.