Headliner in my Freelander started to sag, initially just in corners at the back of the car, but is slowly spreading. I was thinking about “injecting” some glue in between the hard ceiling part and liner and try to attach affected sections again.
Does anyone have experience with this?
Any tips will be appreciated!

do you have a leak somewhere ? Jules

There is a large gap between the lining & the roof. Do you have a moisture issue in the car, maybe a leak from a roof rail mounting bolt holes.

Pulling the ceiling down to find the actual problem is not difficult. The hardest bit is popping off the airbag logo to get to the star bolt to undo, to then remove the trim panels. The trim panels you just need to give a sharp tug.

Have a look at this page & further down, photos behind ceiling https://www.freel2.com/forum/topic33026-33.html Procrastination, mankind's greatest labour saving device!

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I am not aware of any water leaks, and in fact did not even cross my mind. I can have a look as suggested.
The car was parked outside most of the time, so I thought it was caused by harsh australian sun..

Anyway, is anyone aware of a way how to fix this?

Could even be an air conditioning leak on the floor & you have humidity in the car which in turn condensates on the underside of the roof. Could be simply high humidity & if you are not using the air conditioning, may be!

Pull off the rubber gaskets around the doors & have stickybeak around, that's the easiest bit to start with.

If you want to get in completely.
Remove the tailgate gasket.
The 2 shopping bag hooks, anti clockwise.
The boot floor.
The cheap covers either side, wiggle them out.
The 4 tie down points in the boot.
Then the plastic trim along the rear sill.
Then the main boot panel, a strong sharp hard tug the better.
Then the C & D column trims.

I've done this about 4 times now. Second time around it's a piece of cake.

While in there have the vacuum at the ready you will be shocked at the amount to dirt. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

A photo of most of the top side of the ceiling lining in this thread.

https://www.freel2.com/forum/topic32618.html Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

I had a look today in the space between the metal roof and the ceiling, and there were no visible signs of water ever being there, or any signs of aircon leak on the floor. However, since we live near the coast, humidity as a reason is very possible.

I took a photo of how it currently looks like:

If the car was really humid inside you will get condensation on the inside of the windscreen, like when we sleep in the car.

I would cut a small slit in the backing, so you will need to drop the lining. Get some 3M Super 77 from an art supply shop, stick a small diameter tube on the nozzle & stick inbetween the materials. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

If the headlining has de-laminated due to original glue drying out, that glue turns to powder. You would need to take out the whole roof lining , remove the sagged layer, clean up the old powder glue, then glue another lining on.
Big job, there are several YouTube videos on how to do this.



Applying a glue through a slit in the fabric may be a problem as glue will not adhere to old glue power surface. ???

The above mentioned spray glue is in a different league to other stuff. I've used about 100 cans over the years. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18