How to fix the PVC panel above the Garage Entrance

[ihatealldiy]

Hi
My Garage had a white PVC Panel as seen in the photos which has come loose on one side.I think it was stuck to two narrow metal sheets underneath the panel and the panel was held in place with Silicon.

How should I go about doing this?
My plan,remove it completely,clear the adhesive bits and silicon.Then use an adhesive(which one?) and stick it.Then put the border silicon back in place.

If you think, that is the way to go ahead ,I have some questions.

1.What Kind of adhesive? Just ask at B&Q or something in particular?

2.Secondly once I use the glue,how long will it take to hold together? It looks really hard to hold it in place for long.Any suggestions? Do I need to hold it in place overnight?

3. Any particular silicon and do I fix it straightaway or wait for the glue to have worked?

4.Any other suggestions/ideas

Thanks

 

[footprints]

I would use any external silicone to fix and seal, wedge it up with a couple of bits of batten to prop it up over night.

 

[joe-90]

As above,

 

[foxhole]

Double sided foam tape would stick it instantly and very securely.

 

[LastMagicBean]

I'd rip it off, skip it, clean off the mastic and consider the many options of replacing with something more pleasant to the eye.

 

[ihatealldiy]

Double sided foam tape would stick it instantly and very securely.

Can you get it at Screwfix of B&Q?