Thermal Break at Garage Door

[DJFlak]

Hi, I am in the process of building a large garage in northern WI and will be installing in floor hydronic heat. I will have 2" on foam under the floor and 1" of foam as thermal break between the slab and the walls.

My question is... What is the best way to install the thermal break at each of the garage doors. The mason has poured the 4' frost wall and left roughly a 6" deep opening at each of the garage doors so that he can pouring the threashold at the same time as the floor is poured. I know I need a thermal break somewhere... Does anyone have a suggestion for the best energy efficient and yet asthetic and functional approach?

I know he is planning on a black expansion joint between the door threashold and the apron, but my guess is that this would still allow significant heat loss at each door apron...

I need your help and suggestions!!!

 

[Addrock]

You could ask your concrete contractor about adding in closed cell expansion joint material.

 

[Addrock]

How much do you have into Pex for your hydronic heat?

 

[Weedwaka]

I am interested in this also.

 

[Torque1st]

Avoid the door area with the pipes unless you want the heat to melt ice. Keep the pipes 2' from the doors.

 

[DJFlak]

I have a plumber that is doing the rough in all of the floor drains, the bath room shower and all the in floor heat PEX tubing 5/8th inch for 1650 square feet for about $2800...

 

[DJFlak]

I am still trying to figure out... where the thermal break should be...

Does anyone have more specific recommendations.

 

[ScaldedDog]

I just used the normal stuff they put between expansion joints. It does let some heat through, for sure. There are photos in the heating section of how some guys did theirs.

Mark

 

[Racecarl]

I put in 4X8 sheets of 2" (250) extruded polystyrene (the pink stuff) all around the inner perimeter. The vertical sheets start 1.5" below the top of the 6" slab and go down 4'. The horizontal sheets are beneath the slab and extend in 4' from the inner foundation walls. I ripped pressure treated 2X6's into 2" strips and screwed the strips to the inner walls, making absolutely certain the strips were level. I used the strips to screed the concrete as level as possible. The wood protects the insulation from damage.

For the single 16' garage door, I dug a trench across the door opening and installed the insulation to the correct level. I installed a 1.5X2" board in the same manner as the sidewalls. I then backfilled the trench and built forms to hold the concrete in place when I poured the floor. After the floor was poured and cured, I removed the forms, did the subgrade work, and poured the driveway. The board across the door is removable in case it gets damaged or rots in the future.

I can post some pics if I can get the camera away from my kids.

 

[rlme36]

I just used the normal stuff they put between expansion joints. It does let some heat through, for sure. There are photos in the heating section of how some guys did theirs.

Mark

take a look at my build listed in my sig post number 15, but essentially I carried over the vertical portion across the door opening and then had my concrete guy pin the apron to the frost wall and not the slab, due to the pex. The pictures explain it much better, the picture shows the form off from the slab pour and then I added in a piece of foam board across the door. You can then cut it down and fill it the void with something that takes traffic a lot better. I choose wolverines integra flex epoxy. Its really goopy and I used it around the entire perimeter of my slab since the vertical foam poked up an inch or so.

 

[Torque1st]

Concrete is a poor conductor of heat. 2' is normally considered enough to prevent significant heat loss. If you are really worried about the heat conduction from the PEX in the slab to outside then keep the PEX 3' from the doorway.

 

[surfsup]

Concrete is a poor conductor of heat. 2' is normally considered enough to prevent significant heat loss. If you are really worried about the heat conduction from the PEX in the slab to outside then keep the PEX 3' from the doorway.

Interesting concept alleviating any need to deal with the thermal break. Any other comments on this?

I was wondering, if a thermal break is still desired, since the concrete should be poured running out to the front of the garage foundation, is it possible to place a piece of foam vertically across the opening and pour the concrete over it to hit both sides simultaneously, carefully, to not knock it over, by putting pressure on both sides so it can all be done in one shot? or will the curing process compress the foam, etc?

 

[surfsup]

I am having a home built. The architect (Chicago area home) put this together for the detail where the garage floor slab is tied into the foundation/footing and extends out pas the door. The pour, if I were to place a piece of foam under the door, would require another visit from the concrete people which complicates matters into more expense. Anyone have any ideas? I am considering Torque's suggestion to simply keep the tubing 2' from the door, but the thermal R value of concrete is 24" is R=2.5 which is not much.

http://chicagocadcam.com/house/garage.jpg

 

[ct71rr]

Send llwillysfan a PM. I asked him the same question. I think there is an older thread about this on here, as well.

 

[Macguyvermedic]

^subscribed. Building a 24x36 3 stall in SW Michigan, footings in today and walls Wednesday.

 

[surfsup]

Send llwillysfan a PM. I asked him the same question. I think there is an older thread about this on here, as well.

This is what he says:

The best method I've come up with is to run 2" rigid insulation around the inside of the foundation and continue it right across the garage door openings. You then pour a concrete apron 2-3' out from the slab edge over the top of the foundation wall. You can either bevel the top of the rigid insulaion so it doesn't show or cover it with a rubber garage door sill strip.

It's a bit more work to do it this way but it keeps the heated part of your garage slab inside the overhead doors.

 

[Rookie2]

I have 2" insulation under mine and it hangs out 6" , i don't think its too big a loss to live with because i kept the pad i/s the walls and have 2 feet of insulation vertical 360 degrees.
The door threshold is the only place the floor cracked though.

 

[kj_mustang]

Here is what I did. Used the xps and a board for support for my concrete form at the garage door. I wanted the outside pad tied to the interior slab so I ran rebar through the foam and wire tied the rebar and wire mesh together. I had to bend the rebar into a S shape to make the elevation change because my outside pad is lower than the interior. After pouring the interior, I cut the foam form down to expose about two inches of the interior slab. The exterior concrete was poured next and goes all the way over the top of the cut down foam. Here is some pictures.

 

[Rookie2]

You should keep the pex back a couple of feet or more and have the bay at the door on its own zone that way you can reduce the water flow/temp as required. Also don't get carried away in the bathroom, too much heat will dry the p-traps out under the shower.same as above have it on its own heat zone.

 

[stigedis]

In the above 2nd picture, how thick is the cement at the threshold? Ie. over the edge of the foam? 2 inches? Will that crack? Also, I assume the black plastic that is seen is the top of the foundation wall and foam is run on interior wall?

 

[kj_mustang]

The concrete is about two inches thick over the foam and about 5 inches thick right in front of the foam. I hope it doesn't crack. In the first picture,that is a temporary wall blocking the wind at the door and supporting the foam form. The black plastic was from under the interior slab and wrapped up behind the foam and then laid flat after removing the wall as shown in the second picture. There is no foundation wall since this is a pole building.

 

[surfsup]

Can you share how this has been working out for you?

 

[surfsup]

Here is what I did. Used the xps and a board for support for my concrete form at the garage door. I wanted the outside pad tied to the interior slab so I ran rebar through the foam and wire tied the rebar and wire mesh together. I had to bend the rebar into a S shape to make the elevation change because my outside pad is lower than the interior. After pouring the interior, I cut the foam form down to expose about two inches of the interior slab. The exterior concrete was poured next and goes all the way over the top of the cut down foam.

how is that holding up? I'm about to do mine and would appreciate it...

 

[surfsup]

Anyone have ny input on this?

 

[50cal]

I was told to keep the tubing away from the toilets also per the wax ring.

 

[kj_mustang]

My concrete is holding up fine. It has not had very many vehicles over it yet though.

 

[surfsup]

Ok I poured the footings today for mine. Getting close. I think I will separate the garage slab and apron completely with foam (no 2" overpour) and use epoxy over the top or a sealant to make that transition on top of the foam more durable and water/insect resistant.

I'd appreciate any last minute comments from people that have done this...

 

[Michael61]

Hi KJ ! Just got on forum. You're in Virginia, (zone 4) I believe. I'm in Michigan bordering between 5 & 6. I like your idea but still getting the picture(s). When you tied the mesh to the rebar it appears to me there are vertical pieces also that are pinned to the stem wall. I know you made s bends to the elevation change. I was thinking of doing a similar setup only using an expansion strip (1" wide x 10' lengths) Trimming the 2" down to 1". After pour you peel the top strip to fill w/urethane. Please detail and comment.

 

[kj_mustang]

Just saw your post. There were no vertical pieces of rebar in the slab. I had some rebar driven in the ground to hold the foam in place when the garage was poured but I pulled those out. I had leftover foam and used pieces of that instead of wood. There is no stem wall. Floating slab poured inside the pole barn building. You should check out this post also, he did something similar. https://www.garagejournal.com/forum/showpost.php?p=6707746&postcount=8