Hi Folks,
My name’s Greg and I’m a homeowner-to-be here in upcountry Hawaii with a tale of woe and intrigue to share. Our house is in the final stages of construction, and was built slab-on-grade with hydronic radiant floor heating (believe it or not, it does get cold and wet here). My general contractor hired a sub to install TermiMesh stainless steel termite screens in the slab at the time it was poured last November. At their recommendation, we had this sub cut two control joints across the freshly cured slab to control cracking. Can you guess what’s coming next?
Lo and behold, when the plumber turned on the radiant floor system for the first time last week, water gushed up through the cut in the floor. The contractor took the jackhammer to the floor and found that the 1.5 inch deep cut made by the TermiMesh sub had indeed severed the plastic radiant floor heating pipes. Argh. The plumber repaired the severed line and when they repressurized the system, no water gushed out. Phew! So they left the system at pressure overnight…and the next morning my foreman arrived to find water running out the front door and the inside floor flooded. It appears that although they had fixed the biggest leak, there were other small leaks along this same cut.
At this point, my general contractor plans to isolate and repair the remaining breaks in the line in an attempt to salvage this $10,000 heating system. I would like to hear your opinions on the likelihood of the repair being successful. Specifically, I’d like to find out:
– What is the expected lifetime of such repairs to the hydronic floor heat system? Can I expect this to last a lifetime or will I be tearing up the slab again in 10 years to repair the repairs?
– What can be done to ensure that the repaired lines last? The plumber intends to use brass fittings to fix the lines. Will this brass material deteriorate inside the concrete? Would plastic be a better choice? Should brass fittings be coated with an inert substance (epoxy, silicone caulk) before puring conrete onto them?
I wanted to put cork flooring over this slab, but am hesitant to risk ruining $10,000 in cork in the next flood. Needless to say, this has been a tough week. Any advice welcomed.
Aloha,
Greg
Replies
Seems to me someone screwed up big time, either in wrning about the radient heat or in cutting the control joint.
For the dollars involved, you should be contacting the manufacturer of your heating system for either (i) recommended repairs or (ii) a statement that the system cannot be repaired to its original integrity and life expectency.
Then consider contacting a lawyer for advice as to how to deal with the likely shortfall.
Bob is right for the number of dollars involved here!
And I am suprised to learn that you need heat there! Elevation?Excellence is its own reward!
So sorry to hear this. Unless you're willing to forego your RFH, this is gonna get messy for you. Plenty of blame to go around it seems. Surprised the tubes weren't at least pressurized with air before the slab was poured or cut. Having had the experience of putting a hammer drill through a tube in a slab, I'm glad it was pressurized and I'm glad it was air. There's no missing the sound and burst of air and dust in your face even if you're running a drill or saw.
I'd worry more about a nicked tube than a severed tube. They can be repaired and (I hope) last forever with a good crimping. But what about the tube that's cut all but the last mm or two. Might not pop till pressurized w/ hot water for a month, year, whatever. And then where are you? How will they find those weak spots?
I'm guessing you're gonna need a good lawyer on your side.
Hi Greg. I am Richard Miller and as you can tell by my screen name I am kinda involved in RFH (Radiant Floor Heating)
I am going to copy and paste your post here with my comments in red OK?
If you want to cantact me privately you can e-mail me at rich@WarmFloorPro.com
My name's Greg and I'm a homeowner-to-be here in upcountry Hawaii with a tale of woe and intrigue to share. Our house is in the final stages of construction, and was built slab-on-grade with hydronic radiant floor heating (believe it or not, it does get cold and wet here). My general contractor hired a sub to install TermiMesh stainless steel termite screens in the slab at the time it was poured last November. At their recommendation, we had this sub cut two control joints across the freshly cured slab to control cracking. Can you guess what's coming next?
Yeah, I have a good friend on Maui and I learned some neat stuff about your state from him.
Lo and behold, when the plumber turned on the radiant floor system for the first time last week, water gushed up through the cut in the floor. The contractor took the jackhammer to the floor and found that the 1.5 inch deep cut made by the TermiMesh sub had indeed severed the plastic radiant floor heating pipes. Argh. The plumber repaired the severed line and when they repressurized the system, no water gushed out. Phew! So they left the system at pressure overnight...and the next morning my foreman arrived to find water running out the front door and the inside floor flooded. It appears that although they had fixed the biggest leak, there were other small leaks along this same cut.
While it is too late for you please note that the tubing should be kept in the bottom of the concrete. As a related side question is there insulation under your slab?
At this point, my general contractor plans to isolate and repair the remaining breaks in the line in an attempt to salvage this $10,000 heating system. I would like to hear your opinions on the likelihood of the repair being successful. Specifically, I'd like to find out:
At least he is on the right track. But you already knew that.
- What is the expected lifetime of such repairs to the hydronic floor heat system? Can I expect this to last a lifetime or will I be tearing up the slab again in 10 years to repair the repairs?
It depends on the brand of tubing, the connection system used, and the repair technique and quality. Most manufacturers have specs for this kind of repair. A common theme is to use heat shrink tubing over the entire repair connection.
If it is a quality tubing, using a quality fitting, and is done correctly there is no reason to expect less life from the entire system. Maybe you could get the GC to post bond for 10 years or whatever. Talk to a lawyer. If it was my house and was a good tubing with a good connection system I would be perfectly comfortable with my long term prospects.
- What can be done to ensure that the repaired lines last? The plumber intends to use brass fittings to fix the lines. Will this brass material deteriorate inside the concrete? Would plastic be a better choice? Should brass fittings be coated with an inert substance (epoxy, silicone caulk) before puring conrete onto them?
See my request for more info below. I have most manufacturer's repair instructions in my possession.
I wanted to put cork flooring over this slab, but am hesitant to risk ruining $10,000 in cork in the next flood. Needless to say, this has been a tough week. Any advice welcomed.
If done correctly with a quality tube and with quality fittings there should be nothing to worry about.
If you notice I talk a lot about the type of tube and fitting system. If you can find out which brand of tubing you have and let me know I can give you a better idea on what your chances are. Let me know and I'll do my best to help you.
Richard, how would you identify tubing that is damaged and weakened, but not cut completely through? Is this even a concern?
In this case I would do a visual if possible and if not...
Tough situation if no visual is possible.
Bad deal. Bad deal all the way around. It's hard to imagine anyone coming out smiling from a mess like this. Your general is gonna have a chance to show his character here, that's for sure.
Brinkmann for president in '04
You're right on the money Wet Head. People get worried about creating joints because it does increase the chance of a leak but only because the odds are greater. Properly done it will last just as long as anyother joint that is under there. While it's possible that this is all one single tube off the same roll, I'd have my doubts.
You mentioned that the tubes are normally on the bottom. This would not be the case if this was Gypcrete, then the would be in the middle. If it was/is Gypcrete, and I have a feeling it is, then there is no need for the relief cuts. Gypcrete is extremely crack resistant and the relief cuts are doing more harm than good.
Sounds to me like the GC needs to go after the guys that did the Gypcrete and didn't have a clue what they were dealing with.
Oh yeah, I make cabinets now but my Grandfather, Dad, Uncle, Brother, and Cousin, have been doing hydronic heating for many years. Me, well how the heck to do your survive a family get together with out learning a little about it and I worked for my Dad for a few years too. I'm not a pro like you but I've seen enough to know what happened here.Steve - in Northern California
This may not be possible but instead of making many tube repairs could you place a new layer on top of the existing slab? Or make a channel in the floor where the damage is so if repairs are required later, access is possible.
Greg,
You've already gotten good advice in regard to you current problems. What a shame; I hope it all works out for you.
I was wondering about the cork over RFH. Cork is a very good insulator. Did your heating contractor know about your flooring choice and account for it in the design stage?
Love my RFH,
Jerry
Am I the only one wondering about the wisdom of placing a control joint perpendicular to the tube layout. I'm not very familiar with RFH, but a control joint parallel to and in between the tubing runs seams to be a better idea to me. My concern is that control joints are designed to crack, and sometimes even shift laterally. Won't this action sever tubes that were not even damaged by the cutting.
Just a thought.