ᐅ Sound Insulation for Floor Ceilings in Timber Frame Construction (Prefabricated House)

Hello everyone,

we are planning to build a prefabricated house using timber frame construction.

I have compared the quotes, and our preferred manufacturer uses a different thermal and sound insulation system in the ceiling between the ground floor and upper floor compared to the others.

The construction is as follows:

Floating cement screed
Underfloor heating including thermal insulation
P5 wood-based panel
Solid wooden beam ceiling
Inserted thermal and sound insulation 60mm (2.4 inches)
Battens
Plasterboard (GKF) 12.5mm (0.5 inches)

Is this mainly adequate regarding sound insulation?

The other providers use a somewhat thicker plasterboard and especially 100mm (4 inches) of inserted thermal and sound insulation.

I am wondering whether I should also increase it to 100mm (4 inches), or if the current setup is good and increasing it would be a waste of money.

If not, what would be the approximate cost of changing the insulation? Would such a change involve significant additional expenses?

Thanks a lot for your help.

Regards

Sky

Hello,

so in the intermediate ceiling, we have 12cm (5 inches) of insulation, the 6cm (2.5 inches) was only for the installation layer.

As it stands now, I think it’s good this way, we are just about to move in, and in our opinion, you can hear very little noise, even with kids.

Our builder usually uses 10cm (4 inches) of insulation in the intermediate ceilings as a standard.

Maybe this helps you.

Regarding sound insulation, the thickness of the insulation alone is not the only factor that ensures good results. Effective soundproofing is achieved through mass and the combination of different layers. Therefore, a wall with plaster is better than just a slightly thicker wall. Or better yet, a double layer of gypsum board rather than a single layer. Additionally, attention to details is important (such as edge insulation strips at the screed, etc.).

If sound insulation is important, specific soundproofing requirements should always be agreed upon during the construction process! Only this will compel the builder to comply accordingly.

A very simplified approach might be "more is better."

Wooden ceilings are a relatively complex component in terms of building acoustics. Adding more insulation within the cavity does not necessarily result in a higher sound insulation rating. There is still room for improvement in the ceiling structure. For example, the ceiling underneath can be double-layered with drywall and suspended using resilient channels.

Much more important in timber construction, especially in timber frame construction, is the flanking transmission. Even if the separating element is acoustically optimized, if the connections to the adjacent elements are poorly designed, the overall construction’s sound performance will be compromised.

Thank you very much for your help!

I was surprised by the ceiling construction compared to other manufacturers. According to the building specifications, the standard soundproofing according to DIN 4109 is provided.

I am wondering whether increasing the insulation would actually make a difference. Since I work night shifts and then sleep on the upper floor while my wife and our young daughter stay on the ground floor, this is important to me.

It is often said that prefabricated houses are more prone to sound transmission than solid houses.

Best regards

Sky

Skyfire schrieb:
According to the scope of work description, the standard sound insulation complies with DIN 4109.

DIN 4109 sets absolute minimum requirements for protection against external noise and building services systems, as well as between different residential units in multi-family and apartment buildings. Within a single-family home (between living spaces), DIN 4109 does not define any mandatory requirements.

Skyfire schrieb:
I am wondering whether increasing the insulation would actually make any difference.

As mentioned before, the insulation is only one variable in an equation with many unknowns and factors.

Skyfire schrieb:
It is repeatedly said that prefabricated houses are more prone to noise transmission than solid construction houses.

This is a general statement that is true in many (majority) of cases. Simply because it is much easier to build an acoustically good solid construction house than an equivalent timber frame prefabricated house. It is certainly possible, but the planning and execution are not straightforward.