Thermo break at Doorway

[vision8]

What do you use as a thermo break between the floor slab and the foundation wall at the doorway of your radiant heated garage floor?
I have 2" of EPS on the outside of the foundation wall and R20 walls in a Steel Building which I am presently erecting.
Need to put 4" x 2 feet around the inside foundation wall and 2" XPS under the slab. But how do you do a break at the doorway with the top of the foundation wall and also the driveway slab ?
Thanks,
Al

 

[anthony666]

foil backed bubble wrap

 

[Highbeam]

Cut the top of foam at 45 degree bevel, leave it out, or even reduce it to a thinner thickness at the overhead door. Remember, your man door will have a threshold to cover up the top of foam.

 

[Hop2it]

Al, I used 3" Dow foam insulation and capped it with stainless sheet metal that I had bent in a U shape to cover the down board. The rubber seal on the door seals to the stainless the stainless was bought at a local surplus steel supplier, the metal shop charged 1 hour labor about $85 I had 4 pieces bent I don't remember what the stainless cost but wasn't much.Doug

 

[BadgerBoilerMN]

Al, I used 3" Dow foam insulation and capped it with stainless sheet metal that I had bent in a U shape to cover the down board. The rubber seal on the door seals to the stainless the stainless was bought at a local surplus steel supplier, the metal shop charged 1 hour labor about $85 I had 4 pieces bent I don't remember what the stainless cost but wasn't much.Doug

This is a good plan. We are still looking for the perfect solution to this vexing problem.

The 45 cut Highbeam alludes to is generally reserved the point where outside wall meet the slab. At a potentially "heavy" traffic area like a garage door, I would prefer a metal threshold secured to, or buried in the concrete.

Still looking for factory-build but will settle for homemade.

 

[rclassic]

I did a about the same thing only I used 6" wide composite decking board. We poured the concrete on both sides of the 3" wide dow foam and the board is supported by the concrete but protecting the foam.The door seals against it and the seal won't freeze to it.

 

[BadgerBoilerMN]

I did a about the same thing only I used 6" wide composite decking board. We poured the concrete on both sides of the 3" wide dow foam and the board is supported by the concrete but protecting the foam.The door seals against it and the seal won't freeze to it.

I have seen this done. It seems to work. I suppose it is durable enough if it doesn't pop-out in Minnesota weather.

 

[yeldogt]

It is surprising how much of a difference a simple thermal separation makes. I have an attached 2 car garage that I heat with a NG fan forced heater --- I keep the garage about 55 degrees. The house was built in the mid 50's... so the slab is old and obviously no insulation. When I was restoring and adding to this house about 15 years ago the concrete guy I used had done a lot of radiant slabs.

I was replacing the cracked concrete driveway/apron and also wanted to fix a chunk out of the front of one of the three concrete pads that made up the inside of the garage. I also wanted to add a lip getting into the garage to keep dirt and leaves from blowing in.

My concrete guy removed the driveway and cut back all three slabs of the garage floor far enough to remove the broken chunk from the one slab - so I had about an 8" strip of the concrete removed parallel to the inside of the garage door. He then cleaned out just under the face of the cut slabs and inserted 1.5"x12" foam under the cut slab standing up. He then set his forms so the repaired slab end would come just to the inside face of the door....and then dropped the driveway slab 1.5 inches lower to create the lip. Before he pored this driveway he inserted another strip of 1.5 foam -- but he did this two feet down. So what happens -- the driveway slab edge is insulated and the insulated garage door's rubber strip comes down on top of the driveway sealing out the edge of the main garage floor.

What was interesting is my concrete guy told me that he always has the strip of 8" concrete inside the door -- even if no lip is created. He used common tar separators as the thermal separation between the slaps This strip is poured thicker for added strength

My slab is much warmer along the front of the door than it is at the edges where it meets up to the old concrete block on the exterior wall. I have used this technique twice since -- once with a heated slab ... you don't heat the strip.