Issue with front porch archway

Hello all. I have an issue with the top trim of my front porch archway "peeling" away from the rest of the arch. Any ideas? I'm not a handy man at all. Is this something I could fix, or something I should call the pros I'm for?Please see two links below for pics. Thanks!

https://www.dropbox.com/s/oyz3uzwuyq...%20AM.jpg?dl=0

https://www.dropbox.com/s/l5igq41ltg...%20AM.jpg?dl=0

 

It's hard telling what they used there... kind of looks like paper mache now... I bet they used 1/4" underlayment or paneling.

What you use depends a lot on how thick the original one was. My first thought was to use Masonite siding which you can still buy in many places. A piece of composite deck fascia might also be thin enough and flexible enough to work. Both those products are about 1/2" thick however. The composite would definitely last longer. Tempered hardboard is 1/8" or 1/4" thick but would not likely hold up to the weather over the years.

I would think this would be pretty simple to replace if you have a ladder, a skilsaw and can use a drill and some composite screws. You would probably need to remove the 1x2 trim on either side in order to get the new piece in.

Don't be afraid to tear that old junk down. Not like it will look much worse and then you will know what you're dealing with.

 

Looks like the main reason it failed is because there was no flexable J molding around that siding set low enough to cover the end grain so it soaked up water and delaminated.
I'd be replacing it with PVC lumber so it would never fail again.

 

If you use masonite or hardboard be sure to apply a good coat of oil base primer to give it a fighting chance against moisture, latex is fine for the top coat.