ᐅ Which type of stone is best for exterior walls?

Hello,

thomas_neo schrieb:

If the wall is built with an ETICS. Would you rather recommend calcium silicate bricks or Poroton (both 17.5cm (7 inches))?

Today, calcium silicate bricks are usually chosen because of their better sound insulation. If you are building with an ETICS, I would always prefer calcium silicate bricks; otherwise, I agree with Dirk: if I can avoid ETICS, I build monolithically.

thomas_neo schrieb:

Tell that to my wife She even slept last night with the window open at -11°C (12°F). Well, with a heated waterbed, it’s not so bad.

Not really. Although she lies on a warm bed, cold air still passes over the joints. She probably kicks off the covers at night as well; with a warm base – assumedly – more than others. Aside from the disadvantages Dirk mentioned, plus other issues.

Regards, Bauexperte

Hello everyone,

I have now looked at the advantages and disadvantages as thoroughly as possible. I found this quote extremely helpful.

Bauexperte schrieb:


Hello Goldbeere,
Basically, a mechanical ventilation system is always recommended when the wall construction does not allow for air exchange; for example, a single-family house built with external thermal insulation composite system (ETICS / also known as EIFS) => mold problems. Or when both partners work full-time; especially during the period when the house has just been handed over, controlled ventilation is absolutely essential and should be given top priority regardless of the building system.

There is a distinction:

Central systems have a remote installation location and operate almost silently. They have two outlets and two inlets (air exhausted to the outside, fresh outdoor air supplied from outside, stale air extracted from the living spaces, and supply air delivered to the living spaces). Central systems are more complex because ventilation ducts must run from the living spaces to the unit.

Decentralized systems (particularly suitable for retrofitting) usually serve only one room each.

The installation costs for a central system are higher than those for room-based ventilation. Controlled mechanical ventilation with heat recovery is not really cost-effective. Discussions about bacterial contamination vary, often, in my opinion, due to lack of knowledge about new technology. As long as manufacturer-recommended maintenance intervals are observed, in my experience, no problems arise.

Kind regards

From my potential builder, I received the following information:

You can choose a decentralized ventilation system that automatically extracts air in the bathroom, guest toilet, kitchen, and utility room. This involves several wall penetrations through which fresh air is automatically supplied.
If you choose a ventilation system with heat recovery, there are no wall penetrations; instead, the supply air is automatically drawn in by the central unit and conducted via ducts running under the screed through small floor openings into the house.

What I am still not quite clear about is whether heat recovery is really worthwhile. Are there also central systems without heat recovery? The decentralized system costs around €5,000 (approximately) for the rooms mentioned above. I have not received a price for the central system yet.

Good morning,

the developer is called "Pfeil Bauunternehmung from Althütte." They act as a general contractor.
Thank you very much for the information.

Okay, the prices are quite significant. But the more I read, the more I realize that a controlled residential ventilation system in a new build can only be beneficial or at least supports proper ventilation. Especially when building with external thermal insulation composite systems (ETICS) / external wall insulation.

The decision between decentralized and centralized systems isn’t straightforward. First, I need to determine whether heat recovery is cost-effective.

The question of whether a heat recovery system is cost-effective never really arose for me. Firstly, because I wanted a central system anyway, and as far as I know, these are not available without heat recovery. Secondly, because I don’t want to constantly blow cold air into the house at outdoor temperatures of -10°C (14°F). That could also be done with a window frame ventilation system at a much lower cost.

First, decide whether you even want a mechanical ventilation system with heat recovery and if it is worth the investment for you. Then decide whether you prefer a central or decentralized system. The rest will follow naturally. For me, a decentralized system was ruled out simply because of the appearance.

But this discussion is actually about the wall structure, isn’t it?

Good morning,

I think it will be very difficult to achieve a comfortable indoor climate without a controlled ventilation system, since both of us are hardly ever at home. My wife works all day, and so do I; in addition, I am often away on business. This means that “manual controlled ventilation” is almost impossible.

I have now also received the prices for the ventilation systems:

• Decentralized ventilation system without heat recovery €5,000
• Centralized ventilation system with heat recovery €9,500
• Decentralized ventilation system with heat recovery €6,500

I believe these prices are realistic based on what I have learned here. At the moment, I would opt for the centralized ventilation system with heat recovery.

Regarding the exterior wall, in addition to the 3 well-known options:

1. Poroton 17.5 cm (7 inches) + ETICS (standard wall) no extra cost. U-value: 0.19 W/m²K
2. Aerated concrete 36.5 cm (14 inches) monolithic: additional cost €8,900 with U-value 0.23 W/m²K
3. Poroton 36.5 cm (14 inches) T8 monolithic: additional cost €12,200 with U-value 0.19 W/m²K

I have now received 2 more options, which basically improve option 1:

4. Poroton 24 cm (9 inches) + ETICS: additional cost €3,900 with U-value 0.17 W/m²K
5. Aerated concrete 24 cm (9 inches) + ETICS: additional cost €5,300 with U-value 0.16 W/m²K

The more options I get, the more uncertain I become. I think a monolithic build would probably be best. On the other hand, I would not necessarily mind ETICS if we install the centralized ventilation system with heat recovery. Would you prefer option 4 or 5 with the additional costs? Do you see a real added benefit here?

Thank you very much

Hello Thomas,

In my opinion, choosing a central ventilation system with heat recovery was the right option.

As I mentioned in an earlier reply, I prefer a solid wall structure over external thermal insulation composite systems (ETICS, also known as EIFS) mainly for stability reasons.

My parents built their house in 1973 and added polystyrene insulation years later.

Problems encountered so far:

- A New Year’s firework punctured the plaster and lodged about 5 cm (2 inches) deep into the polystyrene.

- Various holes in the plaster and polystyrene caused by “fallen over” children’s bicycles leaning against the house wall facing the courtyard.

- Holes in the plaster and polystyrene from flying debris during strong storms (such as Lothar, Wiebke, etc.).

The damage was always fairly easy to repair, but if you don’t repaint the entire house, the patched areas are naturally very visible.

Regards,

Dirk