ᐅ Sealing an underground borehole

Hello everyone,
since the electrician unfortunately forgot to install the requested conduit for the photovoltaic system during construction (and I only noticed it too late), the cables had to be routed from the outside. A hole was drilled in the basement wall to the outside for this purpose. Once backfilled, this will be about 70 cm (28 inches) below ground level. The drilling went through the masonry, the bitumen waterproofing membrane, and the perimeter insulation. For sealing, black silicone was simply applied around the protective pipe and the perimeter insulation. To me, this doesn’t seem sufficient. What is the usual procedure in such cases? I was thinking about applying waterproof slurry around the area. Or are there other options?
Thanks and best regards

With that, he quickly destroyed the waterproof concrete basement, which was built with the maximum (financial) effort 😡
There are special watertight penetrations designed for this purpose that can also be installed afterwards.
A bit of PU / cartridge sealant, etc., is in my opinion not sufficient here.

You need a "pressure-tight wall penetration or house entry".

i_b_n_a_n schrieb:

With that, he quickly damaged the WU basement built with the maximum (financial) investment 😡
There are specially designed tight penetrations that can also be installed afterwards.
A bit of PU / cartridge sealant, etc., is in my opinion not enough.

You need a “positive pressure waterproof wall penetration or house entry”

Now he doesn’t need anything anymore. It’s clear that the issue should have been handled differently at first.
It depends on the local conditions: groundwater, size and location of the borehole, sealing, side exposed to rain, drainage, and so on.

For example, if the hole went into the insulation somewhere at the lowest basement level and the WU basement is permanently below the groundwater level, then you will have trouble.
But if the drilling was done near the top, just below the paving level, into the basement so that it could also be sealed with waterproof slurry, then it might be okay and just needs monitoring.

I will take a photo this evening.
Basically, it is indeed just under the paving level by about 0.7-1m (2.3-3.3 feet).
Essentially, only a 25mm (1 inch) hole was drilled. Then a protective conduit was inserted, and a bit of silicone was applied around it.

Stefan2.84 schrieb:

I’ll take a photo this evening.
Basically, it is actually just about 0.7-1 meter (2.3-3.3 feet) below the paving level.
In principle, only a 25mm (1 inch) hole was drilled. Then a protective conduit was inserted and some silicone was applied around it.

You don’t have to do that. No one can guarantee safety. The only way is to monitor during prolonged periods of rain like we have had over the past 6-7 weeks.

Because one drop every 10 minutes for 24 hours can cause water damage over 48 hours of undetected dripping.

Since I have mentioned several times, including in writing, to the photovoltaic provider how important the proper building penetration is to me, I will insist on remedial work here. However, I am not sure how this should be correctly carried out according to current technical standards. How should it have been done better?