How can I fix drooping vinyl siding?

Question

I have vinyl siding on my new home. Starting about a week ago, one segment of siding detached on one end and is drooping. The other side is attached just fine.

I tried snapping it back into place, as it looks like each is just supposed to stay in place by snapping into each other. That lasts for about a few hours, and it starts to sag in the middle and eventually the same end detaches and droops again.

My father in law suggested using a galvanized nail and hammer in the siding, but seems like a brute force bandaid. Is he right? What should I do to fix this?

Answer 1

Even though the panels snap to each other they are nailed to the wall at the top edge of the panel. So it's probably a good idea to nail it back. Just make sure it's a little loose because the panels expand and shrink a lot depending on outside temperature.