ᐅ Low Sound Insulation in a Solid Construction House – What Could Be the Cause?

Hello everyone,

We have been living in a solid brick house for just under six months and are very dissatisfied with the sound insulation.
The exterior walls are made of 36.5cm (14.4 inches) thick masonry, and the interior walls are 24cm (9.4 inches) thick Wienerberger Poroton bricks. The windows are triple-glazed, and the interior doors are hollow-core.
Normally, you would expect to hear very little noise from outside while inside the house. However, sometimes it feels as if all the windows are open because you can clearly hear people walking by the house. The closing of car doors and passing vehicles (in a 30km/h (18.6 mph) zone) is also very annoying.
The noise situation inside the house is by no means better. Our bedroom is located right next to the children's room. At normal speaking volume, it is impossible to have a conversation in the bedroom, and if the TV is on, the volume has to be very low; otherwise, our child wakes up.
When the washing machine or dryer is running in the basement, the noise can also be heard all the way to the bedroom, even though the rooms are on different floors and separated by two doors.

Do you have any idea why our sound insulation is so poor? Previously, we lived in a rental apartment and had significantly better soundproofing than we do now.

Thank you very much in advance for your help.

The cause inside the house can only be shutter bridges, meaning incorrect execution of the connections. Possibly also poorly closing "cardboard doors"?
If it is loud from outside, the windows are often improperly adjusted. In the attic, it could be due to the roof structure.

ChrisEF schrieb:

Do you have any idea why our soundproofing is so poor? We used to live in a rental apartment and had significantly better sound insulation than we do now.

Do you have a ventilation system? If so, which one?

Lumpi_LE schrieb:

The cause inside the house can only be thermal bridges at the formwork, meaning incorrect execution of the connections. Possibly also poorly sealing “hollow core doors”?
If the noise is loud from outside, it is often due to incorrectly adjusted windows. In the attic, it could be related to the roof structure.

The doors are already better, but using solid core panels would reduce the noise even more.
We really should take another look at the attic. We also suspect that the noise between the children’s and the bedroom is transmitted through the attic. The attic is insulated with mineral wool, but you can still optimize a lot with wood chipboard panels.
For the windows, we have trickle vents installed for air circulation. These probably let in a lot of noise along with fresh air...

RotorMotor schrieb:

Do you have a ventilation system? If yes, which one?

We don’t have a ventilation system; instead, we control air exchange with trickle vents, which are probably also the reason for the noise.

So our plan now is to finish the attic with wood chipboard panels and replace some doors with solid core panels.

Thank you very much for your help.

It is quite possible that the attic floor is installed over the interior walls without any insulation strips. For the floor, an insulation strip is placed between the floor and the wall to decouple sound. You should also do this at the ceiling, but it doesn’t guarantee improved soundproofing. Adding mass helps significantly, as simply adding more mineral wool doesn’t make much difference. If the ceiling is reinforced with substantial mass, the load-bearing capacity must be considered.

It is strange that the washing machine noise can be heard all the way upstairs. With some luck, you might be able to find out how the sound is being transmitted. Turn the washing machine on and note the volume in the corridor or the adjacent room with the door closed. If the noise is lower there than upstairs, the sound is likely transmitted through the masonry.

Unfortunately, this is almost normal nowadays due to the construction methods used.