Hello Forum!
My first "new topic"...
I am renovating the ceiling in a house from '63. I've read a bit on the forum and elsewhere about whether or not to have a vapor barrier and mold problems in the attic. Grateful for tips and personal experiences.
House facts:
Single-story house with cold attic and basement from '63. Lacks a vapor barrier towards the attic. There's only a windproof paper. The outer walls are Siporex elements. Probably no vapor barrier there either. The attic floor has additional insulation (total about 40cm) added by previous owner in the 70s when a ground source heat pump was also installed. The insulation is the yellow roll/mat type. Despite this, the attic shows no visible mold growth except where the roof has leaked. Almost a bit strange. A new roof was recently installed, where I chose a vapor-permeable underlayer. The house has natural ventilation. Inlet air in basement, so all the rooms upstairs have no air inlet, more than in gaps. Will probably install FTX in a year or so. Have started logging temperature and humidity in the attic.
So.
First, I drywalled the kitchen ceiling but didn't install a vapor barrier. Working on a few more rooms. Some rooms will have to wait a number of years for new ceilings. Trying to seal as much as possible upwards to prevent convection, which is said to be the worst culprit for moisture transport to the attic. The bathroom will be renovated soon, and there, at least, it will be vapor-tight paint.
Questions.
Considering installing a vapor barrier now in the remaining rooms.
1. Do rooms without a vapor barrier face higher stress?
2. Do all the thousands of screw holes in the vapor barrier make it pointless?
3. Can you paint vapor-tight paint in the rest of the house too? Or does it look ugly?
My first "new topic"...
I am renovating the ceiling in a house from '63. I've read a bit on the forum and elsewhere about whether or not to have a vapor barrier and mold problems in the attic. Grateful for tips and personal experiences.
House facts:
Single-story house with cold attic and basement from '63. Lacks a vapor barrier towards the attic. There's only a windproof paper. The outer walls are Siporex elements. Probably no vapor barrier there either. The attic floor has additional insulation (total about 40cm) added by previous owner in the 70s when a ground source heat pump was also installed. The insulation is the yellow roll/mat type. Despite this, the attic shows no visible mold growth except where the roof has leaked. Almost a bit strange. A new roof was recently installed, where I chose a vapor-permeable underlayer. The house has natural ventilation. Inlet air in basement, so all the rooms upstairs have no air inlet, more than in gaps. Will probably install FTX in a year or so. Have started logging temperature and humidity in the attic.
So.
First, I drywalled the kitchen ceiling but didn't install a vapor barrier. Working on a few more rooms. Some rooms will have to wait a number of years for new ceilings. Trying to seal as much as possible upwards to prevent convection, which is said to be the worst culprit for moisture transport to the attic. The bathroom will be renovated soon, and there, at least, it will be vapor-tight paint.
Questions.
Considering installing a vapor barrier now in the remaining rooms.
1. Do rooms without a vapor barrier face higher stress?
2. Do all the thousands of screw holes in the vapor barrier make it pointless?
3. Can you paint vapor-tight paint in the rest of the house too? Or does it look ugly?
Gypsum is relatively diffusion-open. More open than wood, among other things.
