Received a building department comment that reads as follows:
The "Single-Line Diagram" calls for #3/0 to concrete embedded electrode it appears that this building has a monolithic slab. Because of the building code Code requirement that a vapor must be installed under the entire slab thereby rendering the UFER grounding electrode inadequate. Please design another primary grounding electrode system, NEC 250.50.
I understand exactly what the person is saying but it is my understanding that per NEC 250, it is required to bond/ground to all sources available regardless. For instance, if you have a building with 8 feet of copper pipe, then it transitions to plastic pipe, you still need to connect to the copper.
I have been working in my area for a pretty long time and our area is nothing but monolithic slabs on grade (with vapor barrier) and this is the first time I have seen anything like this. I dont really know how effective a 10mm +/-vapor barrier could possibly be at insulating the slab from the ground. Especially since most vapor barriers break down (or) arent installed properly. I have seen vapor barriers after 5 years and they are extremely weak, brittle, and look like Swiss cheese.
Has anyone ran into this before?
The "Single-Line Diagram" calls for #3/0 to concrete embedded electrode it appears that this building has a monolithic slab. Because of the building code Code requirement that a vapor must be installed under the entire slab thereby rendering the UFER grounding electrode inadequate. Please design another primary grounding electrode system, NEC 250.50.
I understand exactly what the person is saying but it is my understanding that per NEC 250, it is required to bond/ground to all sources available regardless. For instance, if you have a building with 8 feet of copper pipe, then it transitions to plastic pipe, you still need to connect to the copper.
I have been working in my area for a pretty long time and our area is nothing but monolithic slabs on grade (with vapor barrier) and this is the first time I have seen anything like this. I dont really know how effective a 10mm +/-vapor barrier could possibly be at insulating the slab from the ground. Especially since most vapor barriers break down (or) arent installed properly. I have seen vapor barriers after 5 years and they are extremely weak, brittle, and look like Swiss cheese.
Has anyone ran into this before?