The partial piece right under the window can need fasteners as it has the nail hem cut off, but anywhere else on that wall should be pretty few and far between. Shake comes in much shorter panels than lap siding so it doesn't need to move as much, but there are some red flags here IMO. If they distorted the panels with a heat gun, face nailing is not the way to fix. Its only a picture and could certainly look different in person, but that looks awfully wavy IMO. I think that you may need some of those panels replaced to get that to look right.

Thank you very much for your insight. This was expensive siding and I learned that my warranty from CertainTeed has been voided by the use of a heat gun and face nails.

With that type of siding, I don't know of a punch tool that allows for snap trim application there.

HomeSealed advice is spot on. The only way to effective install that last small section would be via face nailing it. Maybe Certainteed can tell you what they would have done differently.

You need a slot or a sloppy hole and a nail with a large head to properly fasten vinyl siding to allow for expansion and contraction. You think that's not lying flat now? Wait until some July sun beats on it all day.

Certainteed has an undersill trim for vinyl shakes that helps secure trimmed siding panels under windows. This would have eliminated the need to face-nail under the windows.

2025 update, in answer to a question from cat_ky about the current status of this 2021 issue: The contractor did not acknowledge that anything was done wrong but he waived final payment. I hired another contractor who removed about 75% of the siding from that wall and redid the job, including completely different window trim with

butt joint instead of mitered corners. Face nailing was not done and the siding was re-installed per Certaineed's recommended method. The job has held up and I'm completely satisfied. See attached pic.

The mitre vs. butt joint I don't see being fo any consequence unless someone can tell me if this is specifically precluded in the installation guidlines. As long as the side jamb section of J-channel is overlapped by the head piece, mitre is the more common appplication. That said, the trim on the second picture is a more contemporary look with the 1x4 trim "look". Did they run a wider J-trim there or is it done out of coil work.

On the bottom section, if this is the same set of windows, the larger trim detail on the bottom eliminates the small course on the bottom that will allow them to just run a full course and nail through the nail hem and just cover by the trim.

I do think that the new trim section looks better and is a better finished look to fit the style of the siding and the more contemporary look.

I see in your other thread some closer pictures. That is coil work. Is there J-channel behind the coil?

I don't know of there's J-channel behind the coil but will find out and let you know by end of this week.

Today I was told that the J channel on our butt joint window was an integral part of the PVC trim that was used to re-do the sloppy miter of the original contractor.

I am not sure what "integral" means in this capacity. It is not an integrated J-channel to the window as some new construction windows are equipped with.

I suspect that the J-channel is behind the re-done squared off trim. It is a must in order to manage the water coming off the siding.