Internal insulation for terraced house: floor, ceiling, soundproofing

Good evening,

In an apartment (ground floor, a total of three floors plus basement) in a mid-terrace house, I want to insulate the exterior walls. The exterior facade is plastered. Insulation is not installed there, and that will not change.

Above the apartment is another apartment. The ceiling is a wooden beam ceiling. Below the apartment is the unheated basement. There is a concrete ceiling installed, on which a wooden floor is mounted. The exact structure is not yet known.

The apartment has exterior facades on both long sides. The apartment door opens into the unheated hallway. The interior walls are about 12 cm thick and plastered. A fine plaster was applied.

The walls need to be redone because the fine plaster is not liked. I want to avoid complete replastering with prior removal of the old plaster. Therefore, I am considering gluing drywall sheets to the walls. Insulation could be installed in this process. However, it should only add a little thickness.

The following questions:

1. How can I insulate the exterior walls from the inside? Which insulation material is suitable to achieve minimal thickness?
2. What should be considered regarding vapor permeability?
3. How should I realize connections to interior walls, ceiling, and floor?
4. Does it even make sense to insulate a single apartment in an existing building? Or am I at risk of causing damage to neighboring apartments that are not insulated?
5. How do I deal with window reveals – the reveals at the top are designed as arches?

How should I build up the floor to improve insulation and soundproofing?

How should I insulate the ceiling to also achieve a higher level of soundproofing here? The apartment is extremely noisy. The floor of the apartment above me does not seem to be decoupled at all, presumably planks on the beams without impact sound insulation.

The ceiling heights are quite limited at 230 cm. So there is not much space available.

Best regards, Frank

Hello "Umbauer_1234" You are expecting a complete architectural planning service here, without the person who might respond being familiar with the local conditions. Just this much: interior insulation, whether on walls or ceilings/floors, is a complex subject. Anyone who starts working on a do-it-yourself basis without calculations of the temperature progression within the construction layers, thus without knowledge of the dew point situation, may be very surprised just a few weeks after completing their own work. The building damages that can be caused by incorrectly applied interior insulation are immense! Therefore, I can only advise against tampering with the building fabric with knowledge acquired from forums, especially in combined timber construction. In the worst case, this can even lead to the total loss of the building. Therefore, any advice on this topic can be a nail in the coffin... Not every area in construction is suitable for laymen! ---------------------- Regards: KlaRa

Hello Umbauer1234

I am also very skeptical about the planned project. Without a professional, it won’t work. And you will probably have to completely gut and rebuild. Of course, you can also stick some Styrofoam and drywall to the walls. Fill everything with putty and for a while you will have a nicely insulated apartment. But you will get immense damage to the walls. And after that, gutting is necessary.

Steven
But after

Hello KlaRa, hello Steven,

thank you very much for your answers. Basically, you confirm my "gut feeling": better to leave it as it is. With reasonable effort, such a "block" in the middle of a house cannot be properly insulated.

I have to do the walls anyway. The old plaster cannot remain as it is. And my first thought was: if I stick a drywall panel on, then I might as well use one with insulation. But it's not that simple.

So I will just stick simple drywall panels to the surface. Because knocking off all the plaster and replastering is a huge effort.

When simply sticking panels, there probably isn’t anything to watch out for, right?

Best regards Frank

Is the plaster really in such bad condition? I would simply apply a new fine plaster, paint over it once or twice, and then it's fine. That has always been enough so far, and I can't really imagine that it wouldn't work for you. Can you take some pictures?

Hello garfunkel,

maybe a few background information.

[*]Basically the plaster is fine - however, I do not like textured plaster in the apartment
[*]The electrical system will be completely refurbished - so the walls will be chiseled open anyway

So I have two tasks: On the one hand, to re-lay the electrical wiring, for which I will chisel quite a few grooves. Installation in channels at skirting board height is not an option. For me, the electrical system belongs inside the wall. On the other hand, I want to get rid of the textured plaster. Chiseling it off and replastering is too much effort for me. Therefore the idea to glue plasterboard panels to the walls.

It is really textured plaster that is painted. A fine plaster probably wouldn't help. The top coat, at least I suspect, would have to be completely removed.

Best regards
Frank