Ceiling boards x2 covered in padded cell stuff. Need hidden fixings.

[Sprinter 1 cup]

Thought key hole, thought angle wood .but what elas would hold a 2.5 m x1.10 3mm board plus 6 mm form ceiling board up in my sprinter ? Fixings can be strengthen ers

The boards is in 2 runs the lenght of van lwb around two sky lights and has a 25mm recesses at the moment but im now putting 6mm foam to it so 19mm gap behind the board., would like hidden fixings for no sage and braking ?. So must stay up there.

Must be hidden no battens no fixing though the outerskin
19mm amy size smaller and no glue..
Sprinter roof beams about 50cm apart and up to 6 can be use for 1 board.

 

[Sprinter 1 cup]

I want it like a door card fixings please
I know the key holds are facing the wrong way lol

 

[Squiffy]

If the boards do not need to be removable then I would as I have always done stuck the ceiling board up with evo stick "Sticks like shit". Believe me once it has gone off you could physically hang your body weight from the ceiling. All that is needed is blocks stuck to the roof or roof strengtheners and then the board stuck to these. Of course you have to wait for the block adhesive to set then adhesive on each support block and push the ceiling board up and hold in place with plasterboard ceiling Jacks or appropriate lengths of wood wedged between ceiling and floor till the adhesive has set. To stop damage to the foam use largish squares of 3mm ply. Phil

 

[Sprinter 1 cup]

Still planing it but glue is one way . Why do I need to remove them !. All power / wiress are in cupboard.
Just the maxfan still toyin with it ive got 3 25mm strips running the full interior bolted to the cross members so , maybe
Get photos at weekend.