# Hot water leak fix?



## Hoosier-Daddy

Hi, I am HOPING this can be a DIY fix. 

At this stage I'm not 100% sure of the problem. 

Last night my wife told me the tile floor is warm in front of the sink in a downstairs bathroom. I check it out and can't think of anything but a hot water leak behind the wall seaping under the tile. So I shut off the water to the hot water heater and go to bed. 

This morning the floor is still warm in just that very small area. ????????? It's a ground level tile floor on a concrete slab. That spot is NOT under the heating vent which, this being Arizona is the same as the A/C vent high on a wall, plus we don't heat the downstairs at night anyway. I don't know how the hot water pipes run but this is the closest sink to the hot water heater in the garage with just an office between it. 

I'm pretty sure the hot water is completely shut off. The valve feels good and there are no sounds coming from it. 

But here is why I say I'm not sure of the problem. Even if the heater shutoff (inlet) valve lets a trickle thru, I can't believe it could still be warm enough and volume enough by the time it got all the way to the warm floor to make a difference since it would have to be between the cold concrete slab and the tile. 

But if it still flowing fast enough with the valve closed to warm the floor (with no other signs of leakage) am I right that the leak has to be BELOW the height of the faucet, otherwise hot water would still be trickling out of it. 

This sink has the only faucet in the house with separate knobs for hot and cold and I had left the hot open all night and no moisture in the sink. 

I may be overlooking some other possibility but I can't think of any other source of the heat but hot water. 

Any ideas for another source? 

And if it is hot water, how can I find the location of the leak without tearing up things that don't need to be? TIA


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## SABL

Are all your heating ducts above ground (overhead)?? Some homes have the ducts buried under the slab. 

Another thought is that most heat vents are down low so the warm air will rise.....check for a vent in the "toe space" area under the front of the cabinet or a cutout above the baseboard (semi-concealed) at the front of the cabinet. I have hidden many heat vents (and air returns) by cabinetry.

Is this your first winter in this house??


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## Hoosier-Daddy

Okay, as I said the warm spot was still there this morning even with the hot water shut off all night.

This morning I turned the hot water back on long enough for two quick showers upstairs and shut it back off again.

Now I notice the warm spot in the first floor bathroom is larger. That supports water being the source of the heat.

FYI the shower was on the second floor above the warm spot so it could be a drain leak instead of a hot water leak. BUT I was the only one home yestersay and nobody was upstairs between 7 AM and when the warm spot was found 14 hour later. So that seems to rule out a drain leak although technically I guess it would just rule out ONLY a drain leak. 

But if the heat is coming from a hot water leak how could there still be a warm spot after the hot water heater inlet valve was shut off all night?

I thought more about if the valve didn't completely shut off so I felt the copper hot water heater line going into the house and it was VERY hot while the shower was being used. Now that the inlet valve is closed again, that line doesn't seem to be any warmier than the spot on the floor many feet away. It seems about the right temperture it would be if the flow was shut completely off just because its copper and coming out of a hot water tank. 

That seems to prove a trickle of hot water (valve not closing perfectly) could not have maintained the warm spot all night since the water surely cools a lot between the heater and the warm spot. particularly when the warm spot is on a cold concrete slab.

I must be a terrible plumbing detective because I can NOT reconcile some seemingly absolute facts.


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## Hoosier-Daddy

Thanks Sable,

Those ideas sounded like likely answers.

The heating and cooling ducts are the same and all above ground and in fact all at ceiling height (hot climate so A/C most important).

I guess heat could still leak into the wall space but I wouldn't think the easisest escape woould be beneath a tile floor. And in this case, we don't even run the heater down stairs at night. So I don't think it could be the cause of the warm spot still being there in the morning.

Actually this is our 23rd winter in the house. We are the original owner. I think I may have video somewhere of all the pipes, etc before drywall but even if I could find it don't know if 23 year old VHS would be playable. 

A friend sugested one of our dogs may have layed there but we have never seen them lay there or on any tile for that matter. And they sleep with us and I checkd the warm spot the first thing when I woke up this morning. So I don't think so.

I would really love for this to be something non-plumbing or not a real problem at all.



SABL said:


> Are all your heating ducts above ground (overhead)?? Some homes have the ducts buried under the slab.
> 
> Another thought is that most heat vents are down low so the warm air will rise.....check for a vent in the "toe space" area under the front of the cabinet or a cutout above the baseboard (semi-concealed) at the front of the cabinet. I have hidden many heat vents (and air returns) by cabinetry.
> 
> Is this your first winter in this house??


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## SABL

I was hoping it was HVAC related and you being unfamiliar with the house.....being unfamiliar with the house is not the case. Overhead ductwork rules out the HVAC system producing a "hot spot" on the floor. 

Has your water consumption increased?? If you are on a utility the bill may reflect water usage for the past year...if you have a well there is no way to know unless you installed a meter (never seen that) and have kept track. Is the foundation damp at the closest proximity to the "hot spot"?? If the bathroom is near an outside wall there may be evidence of a damp spot......unless the exterior is brick or the foundation is completely covered. 

I'm still trying to think of something positive.....:grin:. Do you have a circulating type of hot water system?? That's where a return line is installed at the farthest point and returns to a point near the bottom of the hot water tank....as the water in the lines cool down the hot water rises from the tank and the cooler water returns to the bottom. Water is always being circulated even if the cold supply to the tank is shut off. 

If you are leaking enough water to keep the floor warm it has to be somewhat substantial....you should be able to hear something. 

As for pipe location.....underground pipe is nothing fancy and often takes a direct route. You should be able to visualize a line of sight from source to the location where the pipes enter a wall space to go upstairs.


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## Hoosier-Daddy

Sabl, you really know your stuff. Thanks for your posts.

I just got off the phone with a pro and he says its 99% a hot water pipe leaking where it comes up thru the slab. He says it's not that uncommon if the copper pipe got the slightest nick during construction. It will take years but it will eventually leak. He says it's probably been leaking slightly for some time but it all just sits below the slab. It's either just got a little worse or we just noticed a warm spot that may have been there for a while. 

It's not enough to raise any flags on past water or natural gas bills. I may be shocked by the next ones!

He says the leak is probably right under the warm spot but if they see the need they drain all the water in the house and pressurize the pipes with air and use a device that can "hear" the air leak even thru concrete and pinpoint the location.

He also says the cost to fix the leak would probably be covered by insurance but is also probably under my $1000 deductable. I find it hard to believe they can do the repair for that though, but will see. I mean it sounds like they have to remove a vanity, tear out some tile (good luck finding replacements 23 years later), cut out some of the slab and undo all that after they fix the leak.

So it doesn't sound like this will be a DIY job (at least for this Y). But it also sounds like it won't cost me more than my deductable. So I guess my glass is at least half full.


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## SABL

I was trying not to say leak.....:laugh:. The vanity should come out fine.....if it was properly installed and not built in place. Everything is fastened with screws and the cabinets should be able to be salvaged......unless the wife wants a redo of the bathroom....... 

I've also seen "sand holes" in copper pipes......a small piece of grit gets into the extrusion and the pipe eventually leaks a few years down the road. In your case, I doubt the pipe was protected from the surrounding concrete where it emerged through the floor.....when it is repaired I hope they use a foam "wrap" to keep the pipe away from the concrete. 

Wife should be happy....she gets a bathroom remodel!!

BTW...I'm a retired carpenter. I've had to contend with and learn other trades.....makes the job go smoother.


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## Hoosier-Daddy

LoL.

Yeah she won't miss that possibility (remodel). 

I just hope this isn't going to happen with every riser in the near future. I wish my memory was good enough to recall how the pipes came thru the concrete. I visited the site several times a week when it was being built. It wasn't a custom home or anything, so I don't have any specs for stuff like that. 



SABL said:


> I was trying not to say leak.....:laugh:. The vanity should come out fine.....if it was properly installed and not built in place. Everything is fastened with screws and the cabinets should be able to be salvaged......unless the wife wants a redo of the bathroom.......
> 
> I've also seen "sand holes" in copper pipes......a small piece of grit gets into the extrusion and the pipe eventually leaks a few years down the road. In your case, I doubt the pipe was protected from the surrounding concrete where it emerged through the floor.....when it is repaired I hope they use a foam "wrap" to keep the pipe away from the concrete.
> 
> Wife should be happy....she gets a bathroom remodel!!
> 
> BTW...I'm a retired carpenter. I've had to contend with and learn other trades.....makes the job go smoother.


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## danielo

I was going to say it's probably not a DIY job but hopefully it won't cost too much as you say.


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## SABL

For me it's a DIY......wouldn't be my first time for cutting concrete or repairing plumbing. And......I can't afford a plumber....:laugh:. The only thing I stay away from is AC......


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## Hoosier-Daddy

SABL said:


> For me it's a DIY......wouldn't be my first time for cutting concrete or repairing plumbing. And......I can't afford a plumber....:laugh:. The only thing I stay away from is AC......


I'm beginning to think I should have DIYed. 

Here is what's happened with the repair so far. Some things don't seem right and I'm asking if I'm being paranoid or I picked the wrong plumbers. I won't mention names until I know.

I have a contractor friend and he hooked me up with a locator service that preasurizes the lines with CO2 and then uses electronic gadjets to map out where all the underground pipes are and where any leak is. 

They said the leak was under the vanity about a foot and a half away from the center of the warm spot and 20" down.

The contractor decided to help and he arranged for a plumber to come out and fix it (bypass or dig and patch). That guy shows up late and says he only came to look at the situation!?! So the contractor called a big plumber company that he uses a lot (and is highly rated on the internet by customers). So far, so (reasonably) good.

They give me an estimate and it seemed high but since I knew any repairs would be more than the deductable and was in a hurry, I said go ahead. $2,000 BTW. If it was out of my pocket, I would have shopped around some more.

The vanity is apparently 3 sections under the counter and they removed the section above where the leak should be. Since the top stayed and the tile butted up to the vanity (not running under it), he ripped out tiles to remove that section of vanity. 23 year old unubtainable tile, so now the whole floor gets replaced. Then he spent a bunch of time breaking thru the concrete where the leak was supposed to be. He kept complaining that the concrete was much thicker than he expected (priming me for a cost escalation?). 

Then he decided, the leak must not be where they said and started tearing up the concrete in another direction. To get access he needed to remove the next section of the vanity but it won't come out because it has a back which won't clear the sink (one piece with the counter), so he got my permission to cut the back off the vanity. Apparently its glued to the wall because he cuts thru the drywall too. 

But before taking the section out, he decides to take all sections out. So now takes the counter off and removes the rest of the vanity leaving uneccesary holes in the vanity and wall to go with the destroyed tile that was only removed to avoid taking the counter off in the first place.

Okay I guess **** happens and maybe this is par for the course. I'm not in the trades. And honestly, I don't mind things being destroyed since the replacement costs can go towards more modern stuff.

After spending the better part of a day (with an assistant for part) digging and busting up concrete, he declares the leak must not be anywhere near there because he can't find a pipe much less a leak. They say the loactor screwed up.

I call the locator and they have a guy just finishing a job a mile or so away so he swings by. He grabs the plumber's shovel and two scoops down exactly where they said the leak was, there is the pipe and there is the leak in it!?!?!?!?! I mean, this guy (never here before) walks in, looks at the arrows his company put on the floor, grabs the shovel, takes two jabs, says there it is, and walks out. I doubt he was there 5 minutes total.

I don't have a lot of confidence now with these plumbers. Am I wrong? 

And if I'm right, do I kick them out and fight over any bill. And if I don't what should I be looking for when they repair the concrete to make sure its done right. I had asked the guy before he started what they had to do to make sure the new concrete bonds with the old and sets up right (etc). Maybe I watched too many DIY and renovation TV shows but I thought there were special steps needed to make sure the new and old concrete bind as work as well as the original.


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## SABL

Sounds about right with most of today's tradesmen........truly skilled trades-people are hard to find. At least the 'locator' knows what he is doing!! 

I've had plumbers destroy much of my work, even after they were given the opportunity to make provisions that would simplify their 'finish work'. I would contact the plumber in charge and actually show (not just tell) them what situation was present and then tell them what was going to happen......at that time I would suggest what needed to be done that would make their job easier......often I was told that things were fine and they would have no trouble and didn't need to do anything. When I would come back to finish up my job (finish carpentry.....I install cabinets and countertops.....as well as stair systems and handrails) many times I would find destroyed cabinets and/or panelling. Let's just say that they got no break on the 'back charges'......and we often padded the fees as punitive damages. If they don't pay dearly they never learn.....:grin:

OK......in your case. IMO the cabinets and countertop should have been removed at the beginning of the project. The plumber should have coordinated with a carpenter.......from the sound of things you are going to need one anyway. I'm not seeing these guys doing any more than repairing a leak.....and maybe patching the concrete. Reinstalling the cabinets (from what you describe) will be out of the scope of their work.......

**Depending on the size of the hole/s, you may need some steel dowels (rebar) drilled into the existing slab to prevent slippage which will more than likely occur due to the soil being disturbed. Tamping the soil will help but 'pinning' the patch to the existing slab is preferred. As for bonding the patch, just make sure the edges of the existing slab are well dampened with water. They do make bonding agents but I have little faith in them.....all they do is seal the existing concrete and actually provide very little bond. What you end up with is a layer of latex that keeps the moisture from being sucked out of the fresh concrete.......remove the moisture before the concrete has a chance to set and you end up with weak concrete on the perimeter of the patch.

Yes.....plumbers usually travel in pairs.

**If they have kept all slab penetrations under the cabinets you can just patch the concrete......if the patches will be made anywhere else you need to make sure they are solid.


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## Hoosier-Daddy

Fortunately (I hope), I'm done with these plumbers. 

They could not properly repair the leak without removing a lot more concrete because its in/against deeper concrete. I don't know/remember the term but its the equivalent of a bearing wall. Much thicker concrete like at the edges of the slab but also in certain parts of the interior.

They uncovered numerous copper pipes in the same area and said all appear to be on their last legs.

So rather than let them tear out more concrete and fix the one leak and then others in the near future, I'm going to have all the underground pipes bypassed. Basically, the pipes coming up thru the slab (kitchen, laundry room and 1st floor bath) are sealed off and the existing above ground pipes are connected to new hot and cold PEX water lines run thru the walls.


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## SABL

I've seen that very often......thicker slab for load-bearing walls. What I can't see is having to bring the plumbing back up in the wall and disturbing the 'bearing' portion of the slab. There should be an 18" deep (front to back) void under your vanity that is at least 3" high. The plumbing could have been brought through the slab ~12" in front of the wall and elbowed to enter the wall above the floor......the cabinet will hide and protect the pipes. 

Only 23yrs of service out of copper pipes?? What kind of soil do you have in that area?? Most underground copper pipe will be type K and is thicker walled than what is used in the walls.....it is also softer so it flexes with any ground movement. 

All in all it looks like you have a plan......abandon the underground plumbing and install all water lines in the walls. It's far easier to repair drywall than concrete......well, that's easy for me to say after spending my entire career as a commercial/residential carpenter. Most projects I worked on (commercially) were renovations which involved complete tearout and rebuilding entire floors......I can ad lib......:laugh:.


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