Exterior walls are plan bricks, interior walls 11.5 KS

Good day,

can someone possibly tell me if you can use 11.5 cm sand-lime bricks for the interior walls on the upper floor with 17.5 cm Poroton planning bricks for the exterior walls? Or are there any complications in any respect? I would prefer to have 11.5 cm sand-lime bricks as partition walls on the upper floor because they offer better sound insulation.

Regards

MaB

Hello,

could someone possibly tell me if you can use 11.5 cm sand-lime bricks for the interior walls on the upper floor with 17.5 cm Poroton plan bricks for the exterior walls?

Cracks can occur because the “shrinkage behavior” of the bricks is different. So cracks at the transitions between sand-lime bricks and Poroton => in the vertical wall corners where the sand-lime interior wall meets the Poroton exterior wall. The cracks can appear up to 5 years later; it takes that long for everything to settle.

This can be prevented, but it requires the plasterer to make trowel cuts in the corners => the plaster on the Poroton wall is separated from the plaster on the sand-lime wall by a thin gap so that the plaster can no longer crack there.

But this is also the case on construction sites everywhere where chimney flues are connected to the walls behind them. If the plasterer works carefully, usually no problem.

As an alternative, lightweight partition walls are also an option; they have excellent sound insulation and are much better than their reputation ;)

Rhenish regards