harryhausen
2011-04-19 12:14:21
- #1
Hello valued forum members,
I have 3 questions regarding my planned wall assemblies in the existing building (country house built in 1950).
The following initial situations in the existing building:
1)
Wall existing inside → outside → upper floor → north side
11.5 cm inner shell made of pumice stone (pre-war hollow block)
3 cm cavity
11.5 cm solid brick
A supplementary inner shell as a drywall partition is planned.
Constructively: approx. 7 cm air layer → approx. 14 cm mineral wool 035 in a timber stud wall → ProClima Intello vapor retarder → 3 cm installation zone → 1.25 cm gypsum board (see picture 1)
The distance of the cavity between the pumice stone and the drywall partition results from structural reasons and unfortunately cannot be changed or reduced.
2)
Wall existing inside → outside → ground floor → north side or east side
1.5 cm lime-cement plaster
11.5 cm inner shell made of aerated concrete (approx. 600 kg/m³)
3 – 5 cm cavity
11.5 cm shell made of pumice stone (pre-war hollow block)
3 cm cavity
11.5 cm solid brick
An additional interior insulation of approx. 5 cm is planned.
Constructively: 5 cm mineral wool on the plaster → ProClima Intello vapor retarder → 3 cm installation zone → 1.25 cm gypsum board (see picture)
On one hand, the question arises whether these wall assemblies can be executed as planned?
Will too much condensation and consequently mold form in these constructions?
Can an OSB board of 1.25 cm be used instead of the installation zone (3 cm lathing)? Wouldn’t this inhibit the drying back of the vapor retarder, though?
Alternative wall assemblies with insulating stones, etc., should be ruled out because the material is more or less already available, and the existing walls are very uneven. Additional moisture input through plastering work is also not particularly desirable.
Can too much water form in the outer shell with the planned constructions, which then leads to spalling due to frost?
The window reveals are to be finished with silicate boards.
Since I would rather not weaken or damage the existing construction (rafters and masonry, etc.) due to too much condensation, I am turning to you. I have conducted a preliminary calculation with the WUFI program as well as the U-value calculator, but unfortunately I cannot assess the results. (see calculation results)
Thank you very much and best regards
Harald Flessner

I have 3 questions regarding my planned wall assemblies in the existing building (country house built in 1950).
The following initial situations in the existing building:
1)
Wall existing inside → outside → upper floor → north side
11.5 cm inner shell made of pumice stone (pre-war hollow block)
3 cm cavity
11.5 cm solid brick
A supplementary inner shell as a drywall partition is planned.
Constructively: approx. 7 cm air layer → approx. 14 cm mineral wool 035 in a timber stud wall → ProClima Intello vapor retarder → 3 cm installation zone → 1.25 cm gypsum board (see picture 1)
The distance of the cavity between the pumice stone and the drywall partition results from structural reasons and unfortunately cannot be changed or reduced.
2)
Wall existing inside → outside → ground floor → north side or east side
1.5 cm lime-cement plaster
11.5 cm inner shell made of aerated concrete (approx. 600 kg/m³)
3 – 5 cm cavity
11.5 cm shell made of pumice stone (pre-war hollow block)
3 cm cavity
11.5 cm solid brick
An additional interior insulation of approx. 5 cm is planned.
Constructively: 5 cm mineral wool on the plaster → ProClima Intello vapor retarder → 3 cm installation zone → 1.25 cm gypsum board (see picture)
On one hand, the question arises whether these wall assemblies can be executed as planned?
Will too much condensation and consequently mold form in these constructions?
Can an OSB board of 1.25 cm be used instead of the installation zone (3 cm lathing)? Wouldn’t this inhibit the drying back of the vapor retarder, though?
Alternative wall assemblies with insulating stones, etc., should be ruled out because the material is more or less already available, and the existing walls are very uneven. Additional moisture input through plastering work is also not particularly desirable.
Can too much water form in the outer shell with the planned constructions, which then leads to spalling due to frost?
The window reveals are to be finished with silicate boards.
Since I would rather not weaken or damage the existing construction (rafters and masonry, etc.) due to too much condensation, I am turning to you. I have conducted a preliminary calculation with the WUFI program as well as the U-value calculator, but unfortunately I cannot assess the results. (see calculation results)
Thank you very much and best regards
Harald Flessner