Each corner should be hung straight so drop a plumb line for each corner post.
How to install outside corners for vinyl siding.
An assistant is handy at this stage to keep the siding from getting in your way.
Install outside and inside corner posts.
This video shows how to install certainteed outside corner posts for vinyl siding.
The way to allow for this expansion is to install the corner post down from the soffit or top of the corner.
Expansionwhen the temperature changes vinyl siding expands and contracts.
The receptacle flanges on either side of the new corner will hold the siding edges.
Nail into place through the slots in the post with the nail at the top of the slot.
Keep a 1 4 inch gap between the top of the corner post and the soffit.
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.