K
Kennykeks22 Nov 2021 19:47Good evening.
I have a few questions regarding roof insulation and hope someone can help me.
Currently, my attic is being converted.
At the moment, 14cm (5.5 inches) of insulation has been installed between the rafters, and a vapor barrier has been applied.
Now, the construction company wants to install a substructure (battens) to which I can attach a wooden ceiling.
They also plan to add another 6cm (2.5 inches) of mineral wool insulation in the cavity.
I have the following questions.
Isn’t the vapor barrier usually installed at the very end? Meaning no additional insulation should be added after it?
I want to install LED spotlights, which will probably come into contact with the insulation. How is the heat managed in this case?
Also, I want to install speakers in the ceiling, but with the insulation, won’t the sound quality be significantly affected?
If insulation is added after the vapor barrier, could fibers escape through the holes for the spotlights, speakers, and gaps in the ceiling panels?
Thank you very much.
I have a few questions regarding roof insulation and hope someone can help me.
Currently, my attic is being converted.
At the moment, 14cm (5.5 inches) of insulation has been installed between the rafters, and a vapor barrier has been applied.
Now, the construction company wants to install a substructure (battens) to which I can attach a wooden ceiling.
They also plan to add another 6cm (2.5 inches) of mineral wool insulation in the cavity.
I have the following questions.
Isn’t the vapor barrier usually installed at the very end? Meaning no additional insulation should be added after it?
I want to install LED spotlights, which will probably come into contact with the insulation. How is the heat managed in this case?
Also, I want to install speakers in the ceiling, but with the insulation, won’t the sound quality be significantly affected?
If insulation is added after the vapor barrier, could fibers escape through the holes for the spotlights, speakers, and gaps in the ceiling panels?
Thank you very much.
Hi,
Regarding lamps and recessed components, I can only say that they should not penetrate the vapor barrier.
In general, the entire insulation must be fully enclosed.
If you are considering built-in fixtures, there should be a cavity where they can be installed without compromising the insulation and vapor retarder.
From the inside to the outside, there should be a vapor barrier, and from the insulation layer outwards, the assembly should be vapor-permeable. The best option here is multi-layer membranes that fulfill both functions.
The reason is that moisture from inside and outside should not enter the insulation through diffusion or direct infiltration. However, moisture diffusing out from materials like wood due to their inherent humidity must be able to leave the insulation layer so the insulation stays dry and the wooden rafters in this space do not rot.
With this basic assumption, you can consider whether the proposed construction makes sense for your concept.
If you install an additional insulation layer below the vapor retarder, this area must be supplied with sufficient airflow. A tight covering, such as drywall, would probably be too airtight.
Best regards,
Jann
Regarding lamps and recessed components, I can only say that they should not penetrate the vapor barrier.
In general, the entire insulation must be fully enclosed.
If you are considering built-in fixtures, there should be a cavity where they can be installed without compromising the insulation and vapor retarder.
From the inside to the outside, there should be a vapor barrier, and from the insulation layer outwards, the assembly should be vapor-permeable. The best option here is multi-layer membranes that fulfill both functions.
The reason is that moisture from inside and outside should not enter the insulation through diffusion or direct infiltration. However, moisture diffusing out from materials like wood due to their inherent humidity must be able to leave the insulation layer so the insulation stays dry and the wooden rafters in this space do not rot.
With this basic assumption, you can consider whether the proposed construction makes sense for your concept.
If you install an additional insulation layer below the vapor retarder, this area must be supplied with sufficient airflow. A tight covering, such as drywall, would probably be too airtight.
Best regards,
Jann
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