Sound problem: Does noise come through masonry - through the exterior plaster?

Lack of planning, poor construction execution, and poor choice of building materials.

I would now exclude poor construction execution, as this cannot be concluded from a distance. Unfortunately, planning and choice of building materials must probably be accepted as they are. A T9 on a road with an average daily traffic of 6000 is not exactly optimal in terms of noise.

A silly question, but is it useful to additionally fill the masonry joints (which were not closed due to tolerances in structural engineering) with PU foam before applying the plaster? There is this high sound-insulating foam with 60db. Or are there any disadvantages arising from this?

Hi,

a 36 cm T9 unfilled was certainly not a very clever choice by the planner. But now it doesn’t matter, the die is cast.

I’d nicely keep my hands off any experiments with foams. Otherwise the plaster might not adhere properly and you’ll get cracks. At least your plasterer will probably tell you that and use it as a great excuse...

The exterior plaster should make a noticeable difference, it was the same for us. We have 24 cm T14 bricks, which should perform acoustically in the same league as your 36 T9. Before applying the ETICS and exterior plaster, you could “hear through the wall,” afterwards no longer, or rather since then more sound comes through the window frames than through the wall.

What you could possibly do is have the plaster applied thicker.

Best regards,

Andreas

The stone is bad. No patch can help anymore. [Kalksandstein] would have been the right choice.

to fill with PU foam before applying the plaster? [...] Or does that result in any disadvantages

As already says, don’t do any foam nonsense there. Between stones goes mortar and nothing else. Additionally, I would cover that with mesh, as with chases.

the masonry joints (which were not closed due to tolerances in structural engineering)

Joints because of tolerances? – no, I am clearly for “zero tolerance” and even for the introduction of corporal punishment. Because I suspect you are the victim of one of those botched planners who have no idea about stone dimensions and construction reference measurements and just know the wall thicknesses. And who then, for example, distribute the excessive 3 cm somewhat evenly across the butt joints in a 2.77 m wide wall section. That gives in the example an average of just over half a cm play per joint, thanks to the interlocking you can’t see straight through, but professional execution looks different: the plan stones are intended for dry butt joints – but not to interpret the butt joints as a crumple zone/play. Obviously, heat and sound rush through there.

The masons are not to blame, stoning the planners is not their responsibility, and special compensation stones for planners ignoring reference measurements do not exist. Therefore, the masons have no choice but to bridge reference measurement misses smaller than thin-format stones with such improvisation.

Leaving air joints would present similar plaster crack risks as with foaming (both are improper fillings for the joints). I see mortar as the only suitable means; the working hours for that of course must be charged to the “planner.” As far as we are talking about joints of one and a half cm, mortar alone is sufficient; for joints of three or four cm I would already apply mesh.

Just for the misuse of the term “construction tolerances” for such purposes, I would let the “planner” build the next house entirely alone. Then he would have learned it. Is the garage already built? – he could practice nicely there.

Thanks for the answers! I was only concerned about the small joints between the stones here. About 2-5mm in size. The butt joints. It’s clear that the large joints are, of course, mortared. But just filling the small joints with construction foam should help, right? Botch or no botch... as long as there are no serious consequences, the question for me is what is better: leaving it completely open and hoping the plaster solves the problem or closing it with foam and applying plaster on top. They are doing full-surface fabric plastering anyway. I just hope that more really helps... and the description regarding T10 and plaster gives me hope...