Just one extreme example more of the usual resistance to the standard regarding DIN18014.
The first thing he noticed was that the GU’s expert had used the 2007 version of the DIN, including all tolerances and measurement values – also the measuring instrument was not approved by the VDE ...
For execution, the nominal standard valid at the time of completion is decisive.
That the grounding system may only be installed according to NAV by licensed electrical or lightning protection specialists and must be documented before concreting is, contrary to the amendment communications of DIN 18014:2014-03, not new.
More significant is the change of the contact resistance from 1 to 0.2 ohms and the minimum installation depth, see below.
The GU’s expert tried to replace the missing foundation earth electrode and functional equipotential bonding by installing a ring earth electrode around the house and creating connections to the reinforcement of the floor slab in 4 places.
This is an emergency solution but not a full substitute for a PA conductor laid in the floor slab according to paragraph
5.7.2 Combined equipotential bonding system (CBN) of DIN 18014, which must be connected to the reinforcement every 2 m. Even if this emergency solution was implemented, I believe there is still a claim for reduction.
The ring earth electrode itself lies a maximum of 60 cm in the ground, in parts not even 20 cm, and even then in gravel/splinters. Also, it does not enclose the entire structure but was pushed beneath the floor slab at one point (width of that area 2.2 m). The mesh spacing of 20*20 m was also not observed.
Ring earth electrodes installed like this, even with compliant mesh dimensions, do not conform to the
generally accepted rules of technology.
The frost-free minimum installation depth of ≥ 0.5 m according to the old DIN 18014:2007-09 was adjusted in DIN 18014:2014-03 to ≥ 0.8 m to align with building standard DIN 1054 and may require even deeper installations regionally.
We presented all this again to the GU and their expert, but both still claim "everything is free of defects and not dangerous to life or limb".
In the face of such gross errors, one might as well try to get ahead of it. A work is free of defects when it essentially complies with the generally accepted rules of technology (= standards), which is clearly not the case here multiple times.
Whether a danger to life or limb exists primarily depends on the earth spread resistance. How high and during which time of year was it measured? Ring earth electrodes laid continuously with earth contact certainly have better values, and according to my legal understanding, one does not have to accept sufficient but unnecessarily worse values.
My expert said that retrofitting the FPA as prescribed by the DIN is almost impossible or an enormous effort. He also regards the ring earth electrode critically since the mesh beneath the floor slab would also be difficult to install.
The first error could only have been remedied by demolition, which, in my view, would still have been reasonable in terms of effort as long as the basement floor is not yet in place. A ring earth electrode not continuously earth-contacting around the entire house can be corrected retroactively to comply with the standard. Mesh sizes too large at 20 m x 20 m without or 10 m x 10 m with a lightning protection system can be compensated with additional vertical electrodes.