ᐅ Is Insulation Necessary for Poroton Bricks?

bauenmk2020 schrieb:

You don’t need external insulation. If you still want to do something, then use 42cm (16.5 inches) thick exterior walls or 36.5cm (14.4 inches) walls with internal insulation. We also use standard Poroton blocks without insulation, and the soundproofing is not great but not bad enough to be a constant issue. For interior walls, as already mentioned, don’t use 11cm (4.3 inches) blocks. I would now go with 17cm (6.7 inches) or sand-lime bricks.
Otherwise, I think Poroton is a good compromise between sound insulation and thermal insulation.

Ask about your ventilation concept. I’m guessing window frame ventilators. We also use those combined with exhaust fans in wet rooms and utility rooms. Overall, that’s acceptable for a residential area.

From the way the original poster responded, I think the structural shell is already built, so changing is no longer an option... and we have 42cm (16.5 inches) walls, which make no difference compared to 36cm (14 inches) walls in terms of soundproofing... so if anything, always choose walls with insulation.

DerMitDemFH schrieb:

I’m no longer sure about the insulation either.

What is the purpose of the additional insulation? You are already building at least a KfW 75 level house. So, you don’t have to insulate, but you can if you want to increase the energy efficiency of the house.

Please note that with extra insulation, either the building’s outer dimensions will increase, or if the outer dimensions remain the same, the interior space will shrink. In the first case (larger house), you will need a new building permit / planning permission, or your existing permit may no longer be valid. In the second case, a redesign of the entire house might be necessary because you lose space, and then doors or stairs may no longer fit as planned.

Snowy36 schrieb:

But your original question has been answered: you definitely don’t need insulation (-: and you don’t want it anyway, especially if you don’t have a ventilation system.

What does insulation have to do with the ventilation system? The house will be built airtight—whether with or without insulation. Therefore, a ventilation system is recommended in any case. After all, houses can’t breathe, no matter what they are made of. Except for old buildings. But in that case, “breathing” just means there are drafts 😉

DerMitDemFH schrieb:

Hello everyone,

We are building a single-family house with an architect, without KfW funding.
Poroton bricks (the ones with cavities) about 35 cm (14 inches) thick and triple-glazed windows will be used.
Underfloor heating and a heat pump are also included.
According to the architect, additional external insulation is not necessary because the bricks have low thermal conductivity.
Only around the roller shutter boxes is Styrodur insulation applied.
Since he advised us against a central ventilation system due to costs, and I now regret not having chosen one, I’m also unsure about the insulation.

What do you think?

You can achieve KfW 55 standard with unfilled Poroton bricks (36.5 cm (14 inches)) and a heat pump (in our case a ground-source heat pump). At least that’s our experience, and we are building a bungalow, where reaching the KfW standard is usually more difficult. We still decided to install a mechanical ventilation system with heat recovery. Noise insulation was not a major concern for us, as we have no related issues.

Regarding sound insulation, in my opinion, windows and roller shutter boxes (lightweight construction), possibly with internal access panels, as well as the window installation itself, have a greater impact than the exterior wall.

Standard triple-glazed units usually provide less than 35 dB, while a 36 cm (14 inch) Poroton exterior wall offers around 42 dB (I don’t remember the exact figures).

So, I would focus on the weakest point in the chain: soundproof glazing, no internal access panel, brick roller shutter box instead of lightweight construction...

If the window is foam-insulated, make sure the foam fills the entire cavity completely.

Crixton schrieb:

When it comes to sound insulation, in my opinion, the bigger impact is from the windows and roller shutter boxes (lightweight construction), possibly with internal access panels, as well as the window installation itself, rather than the exterior wall.
Standard triple-glazed windows usually offer less than 35 dB, whereas a 36 Poroton exterior wall is around 42 dB (I don’t remember the exact figures).
So, I would focus on what is the weakest link in the chain here (soundproof glazing, no internal access panels, brick roller shutter boxes instead of lightweight ones…)
If the window is foamed in place, make sure the foam fully fills the cavity.

Yes, this advice is not related to the bricks and such, but I also recommend windows with sound insulation values similar to those of the bricks, because today’s standard windows are a joke… yes, triple-glazed, so you might think that’s great, the highest standard. But it’s not. Pay attention to the dB values, even if it’s quiet where you are; it doesn’t cost much more.

We also don’t have insulation; when I look at all the houses with full thermal insulation, they tend to look terrible after a few years, and on top of that, nothing can breathe anymore.