Renovate upstairs handling of masonite?

[joakim_86]

Upstairs in the house, there is currently masonite on the walls inside the room with wallpaper that is nailed into planks, followed by approximately 10 cm of insulation that appears to be clad in windproof paper on both sides. I am considering framing 2x2" on the wall, running new electrical wiring, adding 5 cm of insulation, and then placing a vapor barrier, OSB, and drywall. Question 1 is whether I should remove the masonite or if it can stay in place?
Question 2, the room has a very low ceiling. There is masonite nailed to the raw wood planking, considering if it is feasible to place a vapor barrier directly against the painted masonite and then screw in drywall, as the room only has a 2 m ceiling height so every centimeter added is noticeable. Raising the ceiling in the room is not an option. Grateful for any tips.

 

[Kardan79]

On the upper floor of the house, from inside the room you currently see masonite on the walls with wallpaper that is nailed into planks and then about 10 cm insulation that seems to be clad in wind paper on both sides. I have a thought to frame 2x2" on the wall and run new electricity and add 5 cm insulation and then put a vapor barrier, OSB, and drywall. Question 1 is if I should remove the masonite or if it can stay in place?
Question 2 the room has very low ceilings. There is masonite nailed to the roof boards wondering if it works to put a vapor barrier directly against the painted masonite and then screw drywall, the room only has 2 m ceiling height so every centimeter added is noticeable. Lifting the ceiling in the room is not an option. Grateful for tips.

Doesn't the vapor barrier usually sit on the outside (not room side) of the "installation layer"?

Sorry to just throw out a thought, but soon you'll get help from others who actually know something...

 

[Henrikkkkkk]

Doesn't the vapor barrier usually sit on the outside (not the room side) of the "installation layer"?

Sorry for just throwing out a thought, but soon you will get help from others who actually know something...

No, that's when you get moisture problems. The warm air from inside carries moisture and if the vapor barrier were on the outside, moisture could migrate outward into the insulation until it meets the vapor barrier (which is cold), causing condensation.
When the vapor barrier is on the inside, the vapor never meets the cold air and no condensation occurs.

 

[Kardan79]

No, that's when you get moisture problems. The warm air from inside carries moisture, and if the vapor barrier were placed on the outside, the moisture could migrate outward into the insulation until it meets the vapor barrier (which is cold), causing condensation.
When the vapor barrier is placed on the inside, the vapor never meets the cold air and no condensation forms.

Is it because TS has FAR too little insulation outside the installation layer?

EDIT - I ASSUMED THE WALLS TODAY ARE NOT UNINSULATED.

Every site I've looked at that shows how an external wall should be constructed shows the vapor barrier on the outside (not the room side) of the installation layer.
I've thought it was about a compromise - full vapor barrier = good, vapor barrier a bit into the wall = less good.