Tent roof material and roof rails

[Sp0_0k]

Anybody can please suggest which bolt/screws can be used to mount stuff on the roof rails. For example solar panels.
I see there are couple screws mounted on the roof tent from inside (probably for holding a safety net)
I wanted to make more mounts/hooks on the inside of the roof tent so wanted to know which material is under the fabric. Is there a plywood pannel?
I planned to go just 8mm deep, drilling the holes in it.

 

[Ch1pbutty]

You need the T-track adaptors similar to those used to attach roof boxes etc to roof bars.

Or some solar panels glue directly to the roof.

 

[Hotel California]

You need the T-track adaptors similar to those used to attach roof boxes etc to roof bars.

Or some solar panels glue directly to the roof.

OP wants to fit things on the inside-underside the elevating roof

 

[Ch1pbutty]

I thought he wanted solar panels as well

 

[Sp0_0k]

I admit the questions are confusing.
Yes I need T-track mounts info and 2nd question regarding drilling the roof from inside.

 

[Ch1pbutty]

If you google ‘Brandrup Isotop instructions’, it will show you a strip which you can screw into towards front of the roof. My roof is down at the moment otherwise would have sent you a photo.