ᐅ Remove old fiberglass insulation?

Created on: 11 Nov 2014 14:24
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Hello,
I am planning to buy an older house. The location is ideal, and we also like the surrounding area. The house was built in 1987. During the viewing, I noticed black spots on the bathroom ceiling. I opened a section of the ceiling and found glass wool insulation underneath, which also shows black spots.

I suspect this might be mold, and now I have some questions.
Do I need to remove the glass wool in all the rooms?
Is it really harmful to health?

Update: I contacted a company, and without having seen the glass wool, they said it is carcinogenic.

What do you think about this?
U
Urs1988-1
22 Nov 2014 01:19
Hey,
In my opinion, the black spots are caused by convection currents. The material acts like a filter and becomes discolored. I believe mold only forms in rare cases, unless the glass wool is wet. As long as the glass wool remains installed, it provides insulation.

For your construction project, it is advisable to plan the work carefully. Naturally, professionals should be involved.

Best regards
M
Mattia-1
29 Nov 2014 00:49
First of all, thank you for your replies. I have now decided to only renovate what is visually important. The rest I will leave as it is for the time being.

However, having a sample tested also costs quite a bit of money. I’m not exactly sure, but it’s definitely not free.

I also discovered that the underlay membrane has some holes. Otherwise, everything there is fine. Some time ago, I had the roof cleaned with a pressure washer. During that process, some tiles were pushed out of place by the water, but they remained behind the membrane. I asked the roofer to take a look, and he advised me to install a second underlay membrane from the inside. I think I will go ahead with that.
M
Mattia-1
30 Nov 2014 17:32
I just thought of something else and have a question about improving the insulation. In my opinion, this energy saving might not be very effective.

Does it make sense to fill this with sealant? Or should I just leave it as it is?
Thank you very much for your advice.
B
bastian-1
4 Dec 2014 14:19
Hello,
A thorough assessment is necessary here. This includes providing detailed information about the exact roof structure with layer thicknesses.

The discoloration is 99% likely to be contamination and not mold. Typically, old mineral wool insulation looks like this.

I suspect that your rafters are not fully insulated either. If you now install full rafter insulation, you won’t be the first to soon have to dispose of your roof framework as compost.

A professional needs to be involved here, as only they can make a proper evaluation.

Best regards