ᐅ Exterior Window Sill Capping with Natural Stone Insulation

Hello,

the insulation beneath the exterior window sill made of natural stone is only 1cm (0.4 inches) in our case. The exterior window sill itself is 3cm (1.2 inches) thick. What do you think about this? Is this in accordance with DIN 4108-2?

My assessor says this is far too little for thermal conductivity class 035. The general contractor does not acknowledge the issue and wants to charge me for any potential additional costs.
The construction is using T9 stone with 36.5cm (14.4 inches) masonry.

Here is a picture. Does anyone happen to know what kind of product this is?

Can’t anyone here say something about this?

Spiderman1982 schrieb:

Can’t anyone say something about this?

It could be something like a Jackodur XPS board.

Spiderman1982 schrieb:

What do you think? Is this compliant with DIN 4108-2?

No idea. What does the DIN standard specify, and how was the detail planned and calculated for energy performance?

Spiderman1982 schrieb:

My expert says this is far too little for WLG 035.

What is their reasoning?

Spiderman1982 schrieb:

The general contractor doesn’t admit the mistake and wants to charge me for possible additional costs.

What does the scope of work or the construction documentation say?

nordanney schrieb:

It could be something like a Jackodur XPS board.

No idea. What does the DIN standard say, and how was the detail designed and energy-calculated?

I just don’t have the latest version of DIN 4108 Supplement 2.

Spiderman1982 schrieb:

I simply don’t have a current version of DIN 4108 Supplement 2.

Sorry, me neither. I can only offer you an old version – but that doesn’t help. However, if your inspector says that 10mm (0.4 inches) is insufficient, they must have referred to the DIN standard and based their statement on the justification found there.