ᐅ Concrete foundation grounding (frost protection skirt) improperly installed
Created on: 23 Sep 2018 10:44
M
Mr Unkown
Hi,
we are building a small single-family house. Strip footings (frost collar?) and the slab-on-grade are partially or fully insulated (see attachment). The shell construction work was completely contracted out to a construction company (roof excluded).
Information on the structure:
A type of leveling layer (slightly wider than the footings, interior space is free) made of concrete was placed on the soil beneath the strip footings. The strip footings were then installed on top of this. They were partially insulated on the outside (according to structural engineering requirements, concrete C25/30 XC2). A gravel-sand mixture was placed and compacted under the slab-on-grade. On top of this came a layer of crushed stone, followed by the perimeter insulation of the slab. The foundation earthing (done by the construction company) was executed as a type of ring earth electrode. However, it unfortunately only surrounds about 4/5 of the building and at one point is routed from outside through the strip footing up into the slab. The concrete was then quickly poured, and the slab completed. I was able to take 1-2 photos but no more. Upon later review of the pictures, I noticed that the earthing system has no connection to the reinforcement in the slab.
I now strongly suspect that the grounding system was incorrectly designed/installed.
After some research, I assume that actually a ring earth electrode outside the building with an equipotential bonding conductor (FPAL; fixed to the reinforcement every 2m) should have been installed within the slab-on-grade.
Am I correct in this assumption? If yes, are there any options besides demolition to retrofit an FPAL to the slab?
Regards
Mr Unkown
EDIT: Attachments had to be removed, sorry
we are building a small single-family house. Strip footings (frost collar?) and the slab-on-grade are partially or fully insulated (see attachment). The shell construction work was completely contracted out to a construction company (roof excluded).
Information on the structure:
A type of leveling layer (slightly wider than the footings, interior space is free) made of concrete was placed on the soil beneath the strip footings. The strip footings were then installed on top of this. They were partially insulated on the outside (according to structural engineering requirements, concrete C25/30 XC2). A gravel-sand mixture was placed and compacted under the slab-on-grade. On top of this came a layer of crushed stone, followed by the perimeter insulation of the slab. The foundation earthing (done by the construction company) was executed as a type of ring earth electrode. However, it unfortunately only surrounds about 4/5 of the building and at one point is routed from outside through the strip footing up into the slab. The concrete was then quickly poured, and the slab completed. I was able to take 1-2 photos but no more. Upon later review of the pictures, I noticed that the earthing system has no connection to the reinforcement in the slab.
I now strongly suspect that the grounding system was incorrectly designed/installed.
After some research, I assume that actually a ring earth electrode outside the building with an equipotential bonding conductor (FPAL; fixed to the reinforcement every 2m) should have been installed within the slab-on-grade.
Am I correct in this assumption? If yes, are there any options besides demolition to retrofit an FPAL to the slab?
Regards
Mr Unkown
EDIT: Attachments had to be removed, sorry
M
Mr Unkown28 Sep 2018 12:05Caspar2020 schrieb:
*laughs*
Tens of thousands of buildings now have to be demolished... 100,000. As someone affected, the situation looks different.
Dipol schrieb:
You probably won’t be able to perform a so-called spot check yourself, so you’ll have to request proof from the shell construction company. Proof according to DIN 18014:2014-03 has already been requested.
Dipol schrieb:
What matters is your tolerance for hardship. You’d be the first builder insisting on your legal rights to 100% compliant execution after concreting, with all the consequences like legal disputes and moving in much later. I will likely have to get a construction stop order and initiate a procedure to preserve evidence. The grounding conductor that was protruding from the foundation slab suddenly disappeared as if by magic...
Dipol schrieb:
As an affected builder, you’d be in tears. Unfortunately, that’s exactly how it looks.
Mr Unkown schrieb:
The grounding conductor that was sticking out of the slab suddenly disappeared as if by magic.... Who really believes that the grounding tail was accidentally cut off???
M
Mr Unkown28 Sep 2018 16:08Dipol schrieb:
Who really believes that the connection tag was accidentally cut off??? From Monday, someone else can assess that.
I would like to thank everyone for the helpful comments. Maybe I will write again with the outcome and how we hopefully managed to complete our house with a suitable grounding system after all.
Regards