ᐅ Poor external sound insulation with thermal insulation bricks

E.Curb schrieb:
...and such construction is sold to an uninformed builder as a solid, load-bearing structure

Yes, they sell thin air at a good price

Best regards

bauX2011 schrieb:
Our new house (built in 2011) was constructed using thermal insulation bricks. It was plastered inside and outside with a breathable render. We now have a very good indoor climate and effective thermal insulation, but unfortunately, we are shocked to find that our external walls hardly reduce outside noise. Especially the gable walls, which face perpendicular to the street, seem to trap the outside noise and amplify it like a resonance chamber. If you press your ear against such a wall when a car passes by, it feels as if the car is driving inside the wall. We contacted the brick manufacturer about this problem. They say this kind of sound insulation issue is not known so far.
Has anyone had similar experiences with thermal insulation bricks? What have you done to improve soundproofing afterwards? We would be very grateful for any tips.

Hello!

What a mess! And the posts are becoming more and more helpful.

Hans_Meier hit the nail on the head. Defects can never be completely ruled out, but I don’t see any indication of that here.

Soundproofing is achieved through mass or decoupling. If you exclude the costly measures (like applying a secondary wall) and those not recommended due to potential problems with vapor diffusion, in my opinion, the only option left is adding mass, for example by installing plasterboard panels on the inside. There are reportedly special insulation boards as well, but I am not familiar with how they perform on external walls.

It is really advisable to seek professional advice in order not to make the problem worse by well-intended but ineffective fixes. Whether hiring a building defects expert will ultimately be worth the cost here, I would doubt.

Best regards,
TomTom1

Hello,

TomTom1 schrieb:
In this case, it is really necessary to seek professional advice to avoid making the problem worse. Whether a building defects expert will ultimately be worth the money here, I would doubt.

And where should he get professional advice if not for example from an expert in insulation technology (thermal, cold, and sound insulation) or an expert in noise protection? There are experts and specialist surveyors almost as numerous as grains of sand; unfortunately, this also reflects how frequently disconnected from customers we live today.

Trying to "tinker around" with the possible cause here in the forum is pointless. There are many possibilities, so an on-site assessment is the right way to get meaningful solution proposals.

Best regards

Hello!

To clarify: He should definitely seek professional advice – but not for a questionable legal dispute against the builder, rather for finding a solution.

I don’t see any defect here, nor many options in this regard (and certainly not related to the screed).

A wall must meet three requirements: structural integrity, sound insulation, and thermal insulation. In monolithic construction (essentially the “jack of all trades”), it’s unlikely that excellent performance can be achieved in all these areas.

Best regards,
TomTom1

Thank you very much for the contributions.
I have no intention of suing anyone. I also don’t want to commission expensive expert reports, which wouldn’t improve the situation anyway. I turned to this forum
1. to possibly find others experiencing the same issue. According to both the architect and the brick manufacturer, our problem is completely unknown so far. Apparently, no one before us has complained about the poor sound insulation properties of our bricks.
2. to get advice on how to improve the situation. We already had a large meeting including the architect, structural engineer, shell builder, and brick manufacturer. The gentlemen were silent for about a second before assuring each other that they couldn’t hear any outdoor noise. No surprise, as the outdoor noise isn’t loud enough to drown out a conversation among so many people. From this group, the best advice we got was to hang heavy fabrics on the outer wall and/or place an aquarium to mask the outdoor noise. But under no circumstances should we install a soundproof wall with a vapor barrier on the inside, as that would supposedly ruin our wonderful indoor climate.
As you can see, we urgently need practical advice. What type of specialist should we turn to? And regarding drywall (plasterboard), is it possible to glue it directly to the outer wall from the inside without a vapor barrier?

Hello!

I had assumed an architect would be an expert—after reading the advice shared, I’m no longer so sure.

Gypsum boards (either drywall or fiberboard) can be installed without a vapor barrier directly (with gypsum adhesive); problems only arise with a vapor barrier.

This would only be less than ideal if you plan to screw additional panels on top, which I would recommend.

A battens framework would provide the necessary load-bearing capacity and create some decoupling. On the other hand, the screws could act as sound bridges. My main concern would be shifting the dew point—and that is truly an issue for specialists.

Best regards,
TomTom1