Vertical sealing -> Horizontal sealing

Dear forum members,

let me briefly describe the situation and then ask my questions about waterproofing:

I inherited a house from the Gründerzeit period, around 1908. The basement is masonry and unfortunately the groundwater level is low (area around Leipzig) and the walls are correspondingly damp. The horizontal waterproofing from that time (bitumen membrane) is still present, but probably no longer functional.

Since I want to make the house fit for the next 100 years ;-) I walked through the house with a building surveyor. Regarding the basement, he recommended: "a street-side vertical waterproofing of the earth-contacting masonry".

Then I met with various construction companies for the renovation and they recommended a horizontal waterproofing by injecting a barrier. Once on a paraffin basis (company ISOTEC) and once with Köster Mautrol 2K.

Now my questions:

1. Why inject a horizontal barrier and not excavate from the outside and then apply waterproofing to the masonry, as the surveyor suggests? The basement would stay damp this way and only the moisture would not continue to rise, right? (Note: The basement is not to be converted; it is storage, bicycle room, and trash bin area.)

2. Does anyone have experience with the two proposed injection materials paraffin / Mautrol 2k? What are their advantages and disadvantages?

I look forward to your answers and thank you in advance!

Best regards,
Stephan

The expert simply gives sensible advice, the companies want to make money. Pressing in often doesn’t work, especially when the masonry is already wet. It’s expensive and you need the vertical waterproofing anyway. With the vertical waterproofing, the walls in the basement remain wet, but the capillary action is not enough to reach the story above, so that stays dry. Dry basement: vertical waterproofing all around, horizontal at the base, and a new floor slab with waterproofing. Success not guaranteed. Dry ground floor: vertical waterproofing.

Hello Lumpi_LE,
thank you very much for the quick response.

Yes, it is about a dry ground floor, so I need a vertical waterproofing.

Vertical waterproofing means digging around the house down to the floor slab and sealing it, right?
Do you know which materials have proven to be particularly suitable here?

Thanks and best regards,
Stephan

The important thing is a dry clean substrate, then a 2k bitumen thick coating and protect it with a [noppenbahn].

Hello Lumpi,

thank you for the answers, I will implement it accordingly.

Best regards,
Stephan