ᐅ Compressive Strength of Mineral Plaster Super Lupp

Hello everyone,

we would like to get your opinion.

We have a new build that was completed about 2 1/2 years ago. The masonry is made of pumice stone blocks (Bisotherm). For the base coat plaster, our architect, who was also the construction manager, specified the material LUP222. However, the contractor used the material Super Lupp without consulting the construction manager or us. The exterior facade was not painted after plastering.

In July 2015, there was hail in our region that caused damage to the exterior walls on the weather-exposed side (west / south). The top coat plaster chipped off in hundreds of places. Before this, we had already noticed that our exterior facade is very soft. In many places around the house (about 20 spots), there were already similar top coat plaster chips that could have been caused by light mechanical impacts.

Over the weekend, I did another test: I leaned a metal ladder against the house wall, climbed up and down. At the spot where the metal ladder was leaning, the top coat plaster has now chipped/indented.

According to the contractor and manufacturer, this is normal for mineral plaster (Super Lupp).

Now my two questions:

1. With pumice block masonry, could LUP222 (firmer) have been used, or is Super Lupp required?
2. Is Super Lupp really so soft that you can’t even lean a ladder or a bicycle against the wall?

Do you have any experience with this?

Thank you very much for your feedback!!!

Best regards,
Marcel

According to the manufacturer, Super Lupp is a base coat plaster, onto which a finishing coat plaster must be applied afterward as weather protection. If necessary, a base coat mesh reinforcement should also be integrated.

Thank you for your response above. Of course, a top coat plaster was also applied, as shown in the photo. Nevertheless, the top coat plaster will be damaged if the exterior facade is subjected to stress, for example, by leaning a ladder against it.

Good morning Mr. Kleiner,
Have you been able to identify the cause of your exterior plaster issue and found a solution? I have a similar problem and haven’t received any answers so far... I’m still struggling with it.
Regards
SM

Hello, please send me your phone number, and I will contact you by phone. Good luck MK

Thank you for the quick response. Please send me your contact information or phone number preferably by email to "[E-Mail]capone007@web.de[/E-Mail]". I would prefer not to share my number publicly in the forum.
I would appreciate it.
Many thanks