What is the board material in the picture?

[annabanana]

I have been walking around thinking that it was a porous treetex board behind the wallpaper in this room. Which I thought would be a problem now that I wanted to mount a TV on the wall. But - I see now that it is probably not at all… What are we gazing at in the picture?

Best regards,
Board amateur

 

[HogeN]

looks like the backside of a fiberboard ^^

 

[annabanana]

Thank you @HogeN! This room might have been renovated a bit more extensively once more, beyond what we thought when we bought the house. Does it sound reasonable that one might have put this up around 1990 and wallpapered directly on?

 

[HogeN]

Thank you @HogeN! This room might have been renovated a bit more extensively one more time, beyond what we thought when we bought the house. Does it sound reasonable that this could have been put up around 1990 and wallpapered directly on?

it could have been.

I have Haltex on the walls myself.. applied a thin layer of wallpaper glue and let it dry before putting up the wallpaper.. looks normal but if something falls against the wall, it leaves marks.