FOC
2011-09-05 08:04:58
- #1
Hello,
I want to have an old building (1935), which has an 8cm air gap in the cavity wall, "core insulated" by having Rockwool blown in.
Similarly, the attic and basement ceiling with cellulose.
(1) Is there anything "fundamentally" to consider here, where the executing specialist company might not point it out beforehand, so that later no mold problems or similar occur in the insulated cavity?
I could imagine, for example, that the outer wall becomes extremely cold in winter due to the insulation (since it is no longer heated from the inside...) and water vapor coming through the inner wall and insulation to the outside condenses on the inside of the outer wall because the dew point is undershot there, and the cavity then "floods".
(2) In old buildings, window reveals are always a big problem because the wall thickness relevant for heat transfer is only as wide as the window frame (7cm) due to the construction, so the reveal is very cold in winter and condensation/mold is most likely to occur there if ventilation/heating is poor.
Now, core insulation at this point actually doesn’t help because around the windows there is no cavity to insulate but a layer of bricks with corresponding heat transfer, so core insulation basically (*) changes nothing there.
Are there sensible supplementary measures for a plastered building? For example, I am thinking of PU wedge profiles from 0-4cm thickness, which are glued on the OUTER window reveal to minimize heat loss there (and thus raise the interior wall temperature). Since the building has to be repainted anyway, this could make sense. Does something like this exist? If yes, where? (**)
Thank you very much for your help in advance!
P.S.
(*) Since the core insulation probably starts about 20cm away from the window, the wall temperature at the window will also change somewhat, but I suspect minimally.
(**) Note: Insulation on the inside of the reveals could be done with calcium silicate boards (if there is enough space). I also have good experience with that but don’t like it as much because one has to consider it every time when wallpapering afterwards.
I want to have an old building (1935), which has an 8cm air gap in the cavity wall, "core insulated" by having Rockwool blown in.
Similarly, the attic and basement ceiling with cellulose.
(1) Is there anything "fundamentally" to consider here, where the executing specialist company might not point it out beforehand, so that later no mold problems or similar occur in the insulated cavity?
I could imagine, for example, that the outer wall becomes extremely cold in winter due to the insulation (since it is no longer heated from the inside...) and water vapor coming through the inner wall and insulation to the outside condenses on the inside of the outer wall because the dew point is undershot there, and the cavity then "floods".
(2) In old buildings, window reveals are always a big problem because the wall thickness relevant for heat transfer is only as wide as the window frame (7cm) due to the construction, so the reveal is very cold in winter and condensation/mold is most likely to occur there if ventilation/heating is poor.
Now, core insulation at this point actually doesn’t help because around the windows there is no cavity to insulate but a layer of bricks with corresponding heat transfer, so core insulation basically (*) changes nothing there.
Are there sensible supplementary measures for a plastered building? For example, I am thinking of PU wedge profiles from 0-4cm thickness, which are glued on the OUTER window reveal to minimize heat loss there (and thus raise the interior wall temperature). Since the building has to be repainted anyway, this could make sense. Does something like this exist? If yes, where? (**)
Thank you very much for your help in advance!
P.S.
(*) Since the core insulation probably starts about 20cm away from the window, the wall temperature at the window will also change somewhat, but I suspect minimally.
(**) Note: Insulation on the inside of the reveals could be done with calcium silicate boards (if there is enough space). I also have good experience with that but don’t like it as much because one has to consider it every time when wallpapering afterwards.