Ufer ground vs energy code

[Fred B]

So are we back to having to drive ground rods? After finally getting our local area to accept ufer as a legitimate grounding method, the energy code is requiring 2 layers of foam board and a plastic barrier between the earth and the poured slab. My understanding is that the slab containing the ufer has to be in direct earth contact and the foam insulation prevents that. Is that correct? Seems 1 step forward and 2 ground rods back.

 

[Dennis Alwon]

That is correct. You don't have a ufer if the rebar is not in contact with the earth

 

[Dennis Alwon]

Wait a sec-- a Ufer goes in the footing not a poured slab

 

[Fred B]

Wait a sec-- a Ufer goes in the footing not a poured slab

They were tieing it all together and calling it an ufer, but some are also wrapping the footer in the insulation or using the preformed foam for pouring the concrete insulation inside and outside. Inspector was insisting that the footer and slab be bonded together.

 

[ptonsparky]

Foam under the bottom of the footing? That’s where the ufer is.

Guys are switching to fiberglass around here anyway.

 

[electrofelon]

IMO not using a vapor retarder under a slab is moronic. Not using insulation under a slab that will be in a heated space is also moronic. I also think it is a good idea to use a vapor retarder between the footing and walls. Want anymore of my opinions?

 

[ptonsparky]

If the bottom of the footing is in direct contact with the earth, they use rebar of the appropriate size and placement, you still have a Ufer. We don’t care about the rest.