Insulation of the floor ceiling: Can it stay like this?

  • Erstellt am 2017-08-01 08:57:48

readytorumble

2017-08-01 08:57:48
  • #1
Hello everyone,

we insulated the sloping ceiling (24 cm thickness) and the floor ceiling (12 cm thickness) ourselves with rock wool. We also installed the vapor barrier ourselves.

Now the insulation in the floor ceiling is open upwards, i.e. towards the walkable roof truss, at the sides. There is a gap of about 5 cm.
The roof truss is currently only used as a storage area and the floor is made of ESP boards (with tongue and groove).

See also the pictures. The vapor barrier of the sloping ceiling was connected to the main purlins of the roof truss. Foil = Neovap 20 from Dörken (Sd value of about 20 m)

Now the question: Can it stay like this or do we need to close the gap with foil?
We insulated the whole thing in April, after the moisture from the interior plaster and screed was already out of the house. The insulation is bone dry.

According to the Energy Saving Ordinance, we would have only had to insulate the sloping ceiling, by the way. We then added the floor ceiling as additional insulation (cold and heat protection) as well as soundproofing.

Thank you in advance.

Best regards
ready

 

Lumpi_LE

2017-08-01 09:30:11
  • #2
The gap definitely improves the problem you have created here... You have an attic that will be significantly colder than the living space. However, as far as I understand, there is no vapor barrier between the two levels. Condensation will occur on the chipboards and the roof structure will slowly rot away, since you have sealed everything tightly above it. Put a thermometer upstairs in winter, if it gets colder than about 16° you need to think about how to ventilate and heat the attic.
 

readytorumble

2017-08-01 10:35:11
  • #3
Hi Lumpi_LE,

thank you for your help.
There is a vapor barrier between the upper floor and the attic. It is completely airtight downwards (connected to the knee wall on the plaster of the exterior masonry up to the room corners and also on the plaster of the interior masonry).

In addition, we have pulled a vapor barrier on the attic at the middle purlin up to the ridge. And exactly between these two vapor barriers there is now a gap from above (see photos).
The heated room (upper floor) is therefore completely separated from the unheated attic by the vapor barrier. Only in the unheated attic is the insulation visible.
Sorry for the poor description, it’s not quite easy ;-)

The underlay membrane (under the roof tile) is by the way a completely vapor-permeable membrane (DELTA max Plus with SD value 0.15)
 

Lumpi_LE

2017-08-01 10:38:19
  • #4
then there should be no problems there.
 

Joedreck

2017-08-01 10:44:47
  • #5
There are absolutely no problems if I understood that correctly. I would even pull the panels installed above a few centimeters apart so that in case of faulty foil, the moisture in the wool can escape upwards.
 

Knallkörper

2017-08-01 11:54:58
  • #6
The gap creates rather additional security. It would have been better to use a diffusion-open material for the floor covering / attic. If I understand the construction correctly, the vapor barrier in the attic could also have been omitted. I assume you have an airtight floor insert ladder.
 

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