I have torn down the ceiling (gypsum) in a cabin with a flat roof built in '74. Above the ceiling, there is paper. I perceive the paper as thinner than roofing felt but thicker than today's windproof paper (AC 350). The paper is black and tar-like.
The house was previously passively ventilated with air inflow in the rooms and passive outflow in the bathroom/chimney, etc. I will install a mechanical fan that runs 24/7 in the bathroom.
I have partially torn down the paper to redo electricals, network, etc.
Does the roof need any paper, i.e., do I need to put up new paper?
Does the roof need any felt, i.e., do I need to install new felt?
If it is permanently heated, yes. You need to try to assess the amount of asphalt in the felt and use something equivalent. AC 350 has 350 g/sqm, an underlay felt from that time 1200 g/sqm.
Is the pappen meant to prevent moisture from the shower, cooking, breathing, etc., from migrating into the insulation? Or have I misunderstood the function of the pappen?
Which rooms are you renovating? Usually, nothing is done in old houses unless it's the bathroom. Also, what type and thickness of insulation do you have in the attic?
You can do that if you do it consistently everywhere and ensure that it is tight.
When the house was built, the roof was made in one piece and then interior walls were constructed, meaning the paper and drywall go over interior walls and into the best room. I won't tear down the interior walls, but probably the drywall in all rooms. I won't get it right. Every screw I use to put up the ceiling will puncture any paper or plastic in the ceiling.
Which rooms are you renovating? Usually, nothing is done in old houses unless it's the bathroom. Also, what type of insulation and thickness do you have in the attic?
I'm renovating the entire house. But since the interior walls aren't being demolished, both the old paper and plaster will remain just there.
The insulation in the roof is fiberglass and the thickness is about 20cm.
I did a similar renovation as the house had the same conditions except for roofing paper that was already there. I didn't add any extra vapor barrier at all except for plastic in the bathroom ceiling.
I wouldn't use plastic as you won't get it tight and then risk all the moist air going to one spot and condensing between the plastic and the next layer. Seems like it has worked really well with paper.
Jonatan79 said: