Strong efflorescence on the new building house

Hi everyone,

I wanted to get your opinions on the topic of efflorescence on our new build. I have already read some experience reports from people and know that this is basically a complex issue with many influencing factors. To a certain extent, it can be normal, sometimes it is due to poor workmanship, sometimes a combination of both.

In recent months, we have had a lot of unusually heavy rain, which probably particularly favors efflorescence. We also live in a new development area where the majority of the houses currently have efflorescence. However, it is especially severe on ours. This may also be due, among other things, to the type of stone, which can absorb more water (Wiesmoor erd-bunt).

Affected in our case are primarily the exposure sides (south/east and south/west); on the other two sides you can see very little. It is especially visible on the window sills (the classic on many houses, Photos 1-2) and the side gable under and around the window (Photo 3), but also on a corner edge (Photo 1 right). What especially confuses me are the efflorescence and noticeable residual moisture on the base (Photos 1,4), even though we have dimpled membrane, ventilation joints, and drainage.

Regarding the window sills, I have looked through pictures from the construction phase, and it seems that at least Alujet foil was used everywhere. I can upload it if there is interest.

What is your assessment? Is it the combination of the stone and the heavy weather + maybe the mortar? And do you just remove the efflorescence and it goes away over time? Or do you think there is some fundamental problem somewhere? By the way, brushing and rinsing off the efflorescence does not work well. That rather suggests saltpeter than salt, right?

Many thanks in advance and best regards
Ubibubi

You will probably need to get a damage assessor/construction expert on site. They can assess the situation and advise you, also regarding [warranty] and proper remediation.

Would you say that it is definitely worth it in my case, or isn't that like using a sledgehammer to crack a nut?

Would you say that it's definitely worth it in my case or is that just like using a sledgehammer to crack a nut?

The appraiser might cost around 300€, the damage can have various causes. Construction defects, leaks, incorrect water drainage, etc., the repair can be expensive or inexpensive, you don't know what it looks like behind it and what is rotting away or developing there.