ᐅ Vertical waterproofing → Horizontal waterproofing

Dear forum members,

Let me briefly outline the situation before asking my questions about waterproofing:

I inherited a house from the early 1900s, built around 1908. The basement is made of masonry, and unfortunately, the groundwater level is low (in the Leipzig area), so the walls are correspondingly damp. The original horizontal damp-proof course (bitumen membrane) from that time is still in place but is probably no longer effective.

Since I want to make the house suitable for the next 100 years ;-) I walked through it with a building surveyor. Regarding the basement, he recommended: “a vertical waterproofing on the street-facing side of the wall in contact with the soil”.

I then met with several construction companies for the renovation, and they recommended installing a horizontal barrier by injecting a sealant. One option is paraffin-based (company ISOTEC) and the other is Köster Mautrol 2K.

Now my questions:

1. Why inject a horizontal barrier instead of excavating outside and applying waterproofing to the masonry, as the surveyor suggests? Wouldn’t the basement remain damp and only prevent moisture from rising further? (Note: The basement will not be converted; it serves as storage, bicycle storage, and garbage bin space.)

2. Does anyone have experience with the two proposed injection materials, paraffin or 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, while the companies want to make money.
Pressing in often doesn’t work, especially if the masonry is already wet. It’s expensive, and you still need vertical waterproofing.
With vertical waterproofing, the basement walls will remain damp, but the capillary action is not strong enough to reach the floor above, so that stays dry.

Dry basement: vertical waterproofing all around, horizontal waterproofing at the base, and a new floor slab with waterproofing. Success is not guaranteed.

Dry ground floor: vertical waterproofing.

Hello Lumpi_LE,
thank you for the quick reply.

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

Vertical waterproofing means excavating around the entire house down to the concrete slab and sealing it, right?
Do you know which materials have proven to be especially suitable for this?

Thanks and best regards,
Stephan

The important thing is a dry, clean substrate, then a two-component bitumen thick coating, and protecting that with a dimpled membrane.

Hello Lumpi,

thank you for your answers, I will proceed accordingly.

Best regards,
Stephan