I went into the room under my garage that is fitted with LiteDeck floors tonight and saw fluid the color of the fluid in my hydronic heating system dripping from the center of the ceiling. A quick run into the mechanical room proved that I had no pressure in my system. I have pex in my garage floor. My thought is that the cold snap that we had (temperatures dipping as low as -20F) froze a pex line in the garage slab, despite the fact that the thermostat was set on 50F. The walls are IntegraSpec ICF. They were poured as a monolithic pour with the garage floor. The heating contractor must not have put glycol into the system! Questions: 1. How can this be fixed? 2. Do I have a claim against my contractor that did the work last year? 3. Does my homeowners policy cover this? If so, to what extent? 4. Is the structural integrity of the concrete floor itself now jeopardized? I fear that the only solution would be to cut out the entire floor, re-frame it up, and re-pour. Even with that, I have NO idea how to re-create the strength of my prior monolithic pour. Please tell me that there is another way. Sick to my stomach in Iowa...

I'm sorry to hear about your slab pipe freezing. It's one of the fears I had going into my InsulDeck design so I chose to go with low voltage electric radiant grid floor heating instead of the fluid/pipes within the slab.

I had a radiant heating copper pipe break in an old home slab back out east. The concrete floor had to be jack hammered out and the pipe had to be soldered and new concrete was poured back into the hole. Not easy, not inexpensive.

Call your insurance carrier and see what they cover BEFORE you make a claim. Remember, once a homeowners claim is made, you are entered into the computer system as a "high risk" client for the next 10-20 years. Anytime you go to get homeowners insurance, you will pay a much higher rate. As they say, homeowner claims should be left for complete disasters (fires, tornadoes, etc). If it's a $5k fix, it might be worth paying out of pocket but that is a call you and your agent must make based on deductibles, policy coverage and cash you have available.

You mentioned that you have a room UNDERNEATH a garage floor?


 

PEX is substantially freeze-resistant. It's also hard to understand how a system set for 50F could freeze. Did you notice that the temperature in the garage was cold, say below freezing? Isn't the garage slab insulated? Thermal breaks where it meets the driveway apron?

It's also possible that you had a slow leak which holed up somewhere in the LiteDeck and got released by the weather changes. I had collected rainwater coming down on the sparkies over a year after my InsulDeck floors were poured and dried in.

In order to fix the problem, it will be worth it to see how extensive the "breaks" in the lines are. You might be able to shut off the system, let the slab cool and then slowly turn it back on with a high input temperature using a thermal cam to image it and see if you can find where it is leaking, first. It might be worth jackhammering a couple holes in order to fix point breaks before you plan to redo the entire pour.

Do you have a photos of your hydronic floor installation prior to the concrete pour? If PEX was used, I seriously doubt that it would burst or crack even if frozen. PEX can significantly expand from its original size without bursting. If the hydronic system was running like you indicated, the PEX should not have even froze unless your controller was not using slab temp sensors or your heating source was inadequate or failed. So while it is hard to dismiss the freezing temps, I suspect that the failure may be the result of something else (e.g., perhaps the PEX was damaged during installation/pouring or was improperly installed with tight bends or just tied to sharp rebar). In any event, it should be possible to isolate the failure location and only open up the concrete in that area to make the repair. A good installer should have provided you with a CAD tube design layout and detailed dimensioned photos of the actual installation to facilitate making these sort of repairs.

Pex pipe can and will freeze in a slab.
Sorry. It has happened here in the Great Pacific Northwest.
Here is a quote that well describes your reality;
"When ice is created it takes up more space that water. As the ice grows, it starts to exert pressure on the water that is still in the pex. Since water is incompressible, the pressure exerted onto the pex is extremely high. So, at your burst points, there was water and at the supply and return parts of the loops was frozen pushing the water in the middle".
It is likely not a contractor error as the system ran fine, perhaps the pipes near the garage door got to cold, was glycol used?
When we hit -20 or worse (factor wind on a garage door for-instance) these are spikes beyond standard system design. Systems get pushed real hard, some times to much.
If you are back in a thaw mode, best move now would be to isolate the leaking loop (assuming you are real lucky and have only one loop leaking) shut that loop off, re-pressurize the system, fire the boiler bak up Look for additional leaks and keep the heat on in the area with damaged pipe until you can have the leak located and repaired or abandon the portion of bad pipe and move on.
Glycol is a good thing in the climate zones that can freed bad.
The reality exists that with proper insulation on a slab (2 inch foam) in a bad freeze and system failure the earth heat, 52 degrees, cannot protect the pipe from freezing as the insulation will block that.
Glycol.
Good Luck,
Dan

Thanks for the responses. Some clarifying points:
1. This is not a slab on grade. There is a room UNDER the garage. The slab is insulated with the EPS foam of the LiteDeck product (www.litedeck.com) from underneath.
2. The room under the garage is heated.
3. The setpoint on the thermostat was 50F, down from a prior setpoint of 60F a few days earlier. It had been maintaining temp just fine.
4. The garage door had been left open for about 30 minutes when it was 0F or so outside earlier in the day, dropping the air temp in the garage down to about 45F, thus causing the thermotat, set at 50F, to call for heat. The thermostat does not have a slab sensor.
5. The concrete was a monolithic pour. First the supporting walls for the garage floor were poured, then the pour-in-place beams for the floor were filled (the LiteDeck forms filled, really, which have #7 bar in them at the bottom inch or so that bend down into the walls), then the top 4" where the pex ran was poured. All of these pours occurred on the same day.
6. The garage slab itself extends beyond the heated portion of the garage about 8" or so as it passes beyond the closed garage doors and the driveway apron begins. It strikes me as likely that the break occurred there.
7. The installation contractor and I agreed about the need for glycol. I told him that glycol should be added. He said that it didn't need to be if I kept the system running. I told him to add it, to protect the system in the event of pump failure if nothing else, but I don't have 'proof' one way or the other whether it was added. I suspect it was not since he was borderline belligerent towards the end of the project to the point that I feared somewhat for the safety of my family. Those so inclined can see my other posts questioning his installation practices and techniques on the panel side of things.
8. There are detailed pictures of the installation, yes.
9. There are perhaps five loops in the garage floor that come into a common return. I plan on installing a valve on the common return to allow loop isolation and air test the system to find the offending loop(s).

How can I call my insurance carrier to inquire about what I am covered for in this case without letting them know that I have a problem as suggested?

Let me know what other ideas and thoughts you have! Thanks VERY much!

6. The garage slab itself extends beyond the heated portion of the garage about 8" or so as it passes beyond the closed garage doors and the driveway apron begins. It strikes me as likely that the break occurred there.

I would guess you are correct that this is the source problem area.
If you are lucky pipe there is parallel to door, only affecting one loop.
See if you can isolate that loop.
Dan

PEX can and will freeze in a slab. However, it is extremely unlikely that PEX will burst or crack from simply freezing in a slab. The system should have a pressure relief valve to ensure that the hydronic fluid pressure never comes close to exceeding the PEX rating. Nevertheless, if you somehow managed to freeze BOTH the supply and return sections of a circuit WITHOUT freezing the PEX section between these two points, that could indeed be the possible hat trick that caused this failure. That would be very bad luck perhaps assisted by a bad design/installation.

If you can collect any of the remaining hydronic fluid, you can get an antifreeze tester at an auto parts store to determine if you had any and what amount. It is not unusual to operate without antifreeze to maximize hydronic system operating efficiency. However, when you have an installation that has any risk of seeing freezing, efficiency loss is traded for antifreeze.

I think I would carefully read your insurance policy to find the answer before having a conversation with your agent.

Just to expand on my previous comment about the quality of the design/installation perhaps being a significant contributor to your problem. Normally, one would have a continuous section of the circuit placed parallel to the building outer slab perimeter where maximum slab heat loss occurs and where maximum risk of initial freezing occurs. Furthermore, best practice would be for this parallel perimeter section of the circuit to also be the initial section of the circuit receiving the supply temp so this perimeter section of the circuit will provide a correspondingly higher BTU heat flux. If your CAD tube design layout and photos show that the tube was placed perpendicular to the building outer slab perimeter (and especially if this section of slab is directly exposed to the outdoors), you likely received a design/installation less than best practice and perhaps even avoidable contractor negligence.

There are engineering experts who will work with your attorney to seek legal remedy if you find that this is necessary to obtain satisfaction. Your state may also have contractor licensing requirements and contractor construction board options that you can use to achieve satisfaction without needing to resort to litigation. Where are you located and who did the design/installation?

I started building with ICFs because I was an insurance adjuster for 15 years. All we did was "property" claims, involving houses, commercial buildings. That said, your homeowner's insurance will cover frozen plumbing. Do not hesitate to submit a claim. The policies insurance companies write are the same for all states, with some state specific differences, usually because of legislation. One MN difference is that rates cannot be raised because of claims, they will just not renew a bad risk. Iowa may be the same. But submit a claim, they will send an adjuster out, if you end up not needing them, you withdraw you claim. If it is worth pursuing, and the contractor was contracted to put in antifreeze, your insurance company should subrogate, hiring an attorney and attempt to collect your deductible.

There indeed is a continuous section of the circuit placed parallel to the building outer slab perimeter where maximum heat loss occurs. It makes sense to me that this one would have the highest propensity of freezing. The underside of this slab, the LiteDeck insulation of which remains visible in the thank-God-still-unfinished room below it was framed up to have a slight arc in it for maximum slab strength, meaning that the center of the room below has a slightly higher ceiling than the perimeter edges. What remains a mystery is why I saw the fluid coming from the center (near an integrated floor drain in the garage slab, sure, but it's not as if the drain was left exposed) and not nearer an edge wall. I haven't yet made the time to isolate the loops, but absolutely will get to that this week.

Re: the insurance adjuster work done by ICFconstruction. VERY interesting. A million thanks! What I don't know and perhaps you do, is what the reasonable insurance remedy is for this issue. I mean...the construction was done as follows:
1. ICF walls supporting the garage floor poured
2. LiteDeck beams for floor system filled
3. Top 4"-6" of concrete poured
4. Floor finish

These pours all occurred on the same day within hours of each other. It strikes that perhaps the vast majority of the floor's strength comes from the monolithic pour of the LiteDeck beams in with the wall pour (#7 bar is bent down into the walls). It also strikes me, though, that the only way to truly resolve this issue would be to grind down the whole floor that 4-6" (ack!) to allow fresh pex to be laid into the floor as jack hammeriing where ever the leak was - if able to even be found - could cause structural issues with the floor itself given that it is suspended over living area and needs to be able to hold up three 3/4 ton pickups.

Is there a better way?

Was the HVAC contractor to put in antifreeze? Is it code where you are? Here in MN I have heard it as an option, but it is a no-brainer.

Assuming the PEX was put on the foam and you can pinpoint the leak and it is not over a beam section, coming in from below just through EPS would be the answer.

During the job, I became aware that the HVAC contractor was not planning on putting in anti-freeze. I told him to put it in, but don't know if he ever did. I suspect that he didn't given that I now have this issue. He argued extensively with me about the need for it at the time and even got beligerant, telling me that I should let him do his job, that I didn't know what I was talking about, that I hired him for his expertise, etc., etc. At the end of the day, though, he was supposed to put it in.

The PEX was put on the LiteDeck foam. I am not confident that I will be able to pinpoint the leak. With my Fluke thermal camera, I can readily see the loops in my gypcrete floors inside, but have never been able to see the loops in the garage concrete floor sadly. Perhaps there is some special trick that I am not aware of.

Was the drain in the middle of the floor plumbed with a trap? Could have had water in it with no antifreeze.

Just a thought, Chris

Never mind I re-read and see you have lost pressure.

The drain in the middle of the floor was indeed plumbed with a trap, but that would have only caused the trap to freeze instead of causing the whole hydronics system to de-pressurize. Further, the fluid leaking through the ceiling from below was colored red - the same color as the fluid in the system. The biggest question in my mind is how it is that the leak manifested itself with drips coming from the center of the floor.

Isn't the red fluid, antifreeze?

No. The red fluid was some sort of pH inhibitor. I can check the name tonight, but I think it was maybe Chemsearch 777.

Posted By ICFHybrid on 09 Jan 2014 10:08 AM
PEX is substantially freeze-resistant. It's also hard to understand how a system set for 50F could freeze. Did you notice that the temperature in the garage was cold, say below freezing? Isn't the garage slab insulated? Thermal breaks where it meets the driveway apron?

It's also possible that you had a slow leak which holed up somewhere in the LiteDeck and got released by the weather changes. I had collected rainwater coming down on the sparkies over a year after my InsulDeck floors were poured and dried in.

In order to fix the problem, it will be worth it to see how extensive the "breaks" in the lines are. You might be able to shut off the system, let the slab cool and then slowly turn it back on with a high input temperature using a thermal cam to image it and see if you can find where it is leaking, first. It might be worth jackhammering a couple holes in order to fix point breaks before you plan to redo the entire pour.

\ I can find no truth or logic in any of this.

It is not required in any model code to use anti-freeze on a radiant floor, in the garage or otherwise. If the room were 50°F it would not freeze a tube. We design systems for garages and don't always use antifreeze. If you do, you pay for insurance twice. Once to operate boiler and pump with roughly 10% more energy and again to pay for insurance. If you have insurance you have a claim.

If you have anti-freeze in a hydronic system, you have to maintain it. If you have a radiant floor in your garage, you have to maintain the boiler to make sure the system is reliable. A freeze alarm is always a good idea for the the unwary or snow birds.

High risk?...maybe for car insurance. Three years ago we flushed bad antifreeze out of a system for a commercial insurance agent. It seems the contractor fill the whole system including several thousand feet radiant floor in the basement and a three car attached garage. He said he had insurance, leave it out. This was in Stillwater, a suburb of the Twin Cities.

PEX freeze resistant? Sorry, not once encased in concrete. I guarantee a leak or two.

Slow leak? Like a little bit pregnant. I doubt it.

As for a fix. Call the insurance agent. It may be that a perimeter loop can be fixed, we've done it. But first fix, then pressurize. If you have more than one leak the whole panel comes up and new one installed. If you get the check and decide a high intensity infrared will do, well...

A hate to say it, but you might want to call an expert.

Thanks for the reply, Badger. In my experience, there are experts scattered over the country but none where I am. I have called and spoken with several supposed local experts only to be scared away when they say things that don't make any sense whatsoever (use of non-barrier pex is a good idea, loop lengths don't matter, it's a good idea to use one pump per zone in conjunction with a zone valve per zone, yep - I've heard it all). I figured I'd start here and see what you guys - the true experts - thought.

I am most concerned about ensuring the best fix for this. I don't know if that is to grind off the top 4-6" of floor surface and re-lay tubes or what. That is the key information that I am at this point seeking and tremendously appreciate any advice you fine folks can share.