Detecting leak in Warmboard with partially installed finished floors

jlehrman

I'm in the process of doing significant renovations. I've installed the warmboard panels, pex and manifold for one floor (~1000sqft). The system was (air) pressurized and everything was good. The boiler has yet to be connected. I'm using the AL-PEX supplied by Warmboard.

I've been putting down engineered wood (3/4") with staples. I thought I was being very careful but it looks like I hit the PEX on two (of the six) loops as I noticed leaks. I confirmed which loops by isolating them. In one of the rooms, about 50% of the flooring is done. In another it's about 80% done. Both leaks are very slow... maybe 5 PSI every 12 hrs (when all 6 loops are connected).

I really want to try and find the leak without picking up all the boards until I find it (time and cost).

I tried an ultrasonic device off of Amazon ($50). Didn't work. I called a plumbing company that had high-end FLIR IR camera's. We tried putting the air compressor outside (~0C) to get a temperature differential. They weren't able to see through the 3/4" finished floors and we could see that the air warmed up pretty quickly where the PEX was exposed.

I was thinking for my next step I could attach the manifold directly to a hot water tap (isolating a single loop) and use a FLIR One Pro. I'm concerned I might cause more damage and/or the water won't actually be leaking. Are there any devices that would allow me to heat the compressed air prior to pushing it through the PEX.

Any ideas on what I can try next? I'm in Montreal.

TIA.

Jamie Hall

Hot water and patience and the IR camera is your best bet. But -- you'll have to keep the water hot and under pressure. The thing to remember here is that the offending staple or staples are likely to be partly sealing the holes, and the leak will be slow and will take time to show up.

Air sounds attractive, but... you can't use hot enough air at a leak rater that slow to make the leak vicible.

STEVEusaPA

Are you sure it's not leaking at the manifold? Depending on the connection type, a fiber washer will leak air until wet (or unless kept wet).

jlehrman

Thanks for the feedback @Jamie Hall

@STEVEusaPA: I've tested with soap and it also went from a non-leaking state (couple of weeks) to a leaking state without touch the manifold.

jlehrman

@Jamie Hall Once I'm done with the test, I would then flush the water out with compressed air?

Jamie Hall

why?

hot_rod

What brand if manifol. Some gave hydroscopic air vent that will bleed off air pressure

jlehrman

@Jamie Hall I would want to remove all the water in the PEX so I can splice and repair and leave pressurized with air until I'm finished putting down the rest of the finished floors.

jlehrman

@hot_rod It's a Warmboard manifold. There's a vent to bleed air pressure, but I've kept it closed. With other loops, the pressure has been maintained.

hot_rod

I’ve repaired a few WB jobs from below instead of removing flooring

infrared cameras find leaks quickly, then I have whittled  away the wood from below the area if the leak

you need access from below and block under the areas where you may weaken the WB

100 psi shows leaks faster than 10 psi, as long as everything is rated for 100 psi. Boilers aren’t 

TAG

Did a church conversion using 3/4" wide white oak over Warmboard S a couple years ago. Arrived one day to find the boiler pressure at zero. We had installed the system and had it up and running for about two months to provide both building heat and to acclimate the oak flooring prior and during install. Figured it was most likely a staple someplace in a recent area. Having been burned before making assumptions (what if another trade had hit an odd line) -- refilled the system a couple of times and not finding any water anywhere started to isolate the manifolds (4) starting with only the oldest work area open. As I opened each manifold the pressure held for two days until the last manifold and sure enough the pressure was low the next day. We had about 4k sf of Warmboard and this last manifold had both crawlspace and finished ceiling under the floor ... was not happy. The flooring installer was fully instructed on the job (minimum board edge to Pex) and did a beautiful job. Still not seeing any water anyplace I started to layout the Warmboard Pex loops. It was not very hard ... had the layout from Warmboard and many pictures of the job showing the panels and any odd route that had to be made ... quickly discovered one board edge that was IMO too close to where my layout said a Pex run should be. Having this new knowledge I isolated out just that loop and the system ran w/o issue for a few days. It was only after I opened this last loop for the final time and over pressured the system -- that I noticed a drip and some wet insulation in the crawlspace. I had the flooring guy cut out the suspected line of boards and sure enough he called to say it was hit many time. The flooring guy then told me the lead allowed another person to work on the floor who had not been fully instructed and did not understand the full staple angle possible.

The solution was to take out and replace the Pex --- that became another issue. The contractor started to cut square holes and fix the Pex with the wrong splice. Regular plumbing and not Al Pex. I used a large whole saw and simply drilled holes for my patch locations. On the one end the Pex was missed as it got to the curve -- on the other end they got it too close to the curve for the proper patch connector and even hit the cross Pex. My solution was to remove the next board that thankfully was short and make the proper space for the AL Pex connector from Warmboard.

Couple of things to note. Since the panel is covered in one sheet of Aluminum -- the groves can hold a lot of water before any leaks out -- this will depend on the leak location on the panel obviously. This is why I never found any water until the very end. Also -- with the Al and the tight grove -- I'm not sure you will see any difference with any heat gun between anything leaking out and the actual Pex.

IMO -- You should layout the floor and see where the obvious close contact points are. Remember -- you can glue the flooring to Warmboard. Remove the tongue and glue in the fix. I have always used some glue -- even when doing an addition to a typical strip oak floor I used a few drops along a line to keep out any possible movement/ noise. Here we needed to fully gue as the boards are up to 14" .. Warmboard has an approved glue list

hot_rod

Different opinions on gluing down hardwood. Engineered woods typically okay. Solid wood needs to move a bit with humidity changes, that is why you have the T&G joint to accommodate movement. The wider the board the more potential movement.

Panelization is what can happen when the wood is stuck down with glue. It’s pretty ugly when it happens.

A good wood supplier will know how to fasten the various woods.www.launstein.com has done a lot of research on wood over radiant, they and the oak flooring association used to do seminars at RPA meetings.

Just a heads up.

TAG

hot_rod said:

Different opinions on gluing down hardwood. Engineered woods typically okay. Solid wood needs to move a bit with humidity changes, that is why you have the T&G joint to accommodate movement. The wider the board the more potential movement.

Panelization is what can happen when the wood is stuck down with glue. It’s pretty ugly when it happens.

A good wood supplier will know how to fasten the various woods.www.launstein.com has done a lot of research on wood over radiant, they and the oak flooring association used to do seminars at RPA meetings.

Just a heads up.

Making sure the wood is properly dry and stays that way is paramount. The nice thing about Warmboard is that full panel Al layer. No moisture from a basement or slab is going to be traveling up to the underside of the finished floor boards and changing the humidity level of one side of the board. Warmboard also allows for the lowest water temp. Another major area is the subfloor ... I have seen panelization shown and it always seems to occurs as the subfloor moves and pulls the finished floor with it. When doing a retrofit system there is always a possibility of finished floor movement because the subfloor is going to move ... different systems are going to have hotter water ... more heat will dry out a floor. I have seen more movement over plywood vs random board subfloor system of old.

With wide boards you almost have to glue and the approved glues today have a bit of give to them vs the rock hard of old ... I still advise to keep glue out of the T&G. I personally have never had an issue with wide boards and Warmboard and I was a very early user of the product when it came out in the early 00's.

Warmboard may be an expensive product .... but it has a lot of advantages that can't be ignored. Warmboard has almost 30 year history and I have never seen any of the floor or wood associations using it as the subfloor when testing .... another issue is floor finish. Floors not acclimated can have finish cracks and cracks of the joint when the floor drys .... The finish is acting as a glue as it seeps into the joint.

As an added step -- I also give a quick once over to the underside of all the boards before they go down and after they have been in the rooms for a while. Time is important and that is often a rare commodity when doing new construction

jlehrman

Thanks for adding to the conversation. Very helpful. What do you consider a safe distance from the edge? I assumed that with a 2" staple at 45deg, anything over an 1" was safe. I checked all the obvious places and nothing stood out.

A friend suggested a borescope.. and it looks like they would fit inside 1/2" PEX as long as the bends aren't too tight. The problem woud be length. Have any of you tried this?

I've managed to take up a few boards without damaging them - so I think that's how I'll proceed.

On a side - I did a test. I pressurized some AlPex and use regular PEX crimps. I was pleasently suprised to see that it's still holding after a few weeks. I'm thinking I might use this in exposed portions. AlPex connectors are very difficult to get in Canada.

hot_rod

Pexalpex couplings have dual o-rings to make a better seal. A more substancial crimp collar also. Looks like Mr Pex still offers these. It does require a specific crimp tool.

I hate to see you put water against that new hardwood, but hot water shows quickly with IR cameras. I'd wonder that hot air would also? Helium can be used with a gas sniffer. Often used to find micro leaks in vacumn systems.

I took a hardwood installer class at the old NOFMA, the national oak hardwood flooring manufacturers association, Micky Moore was the tech director and instructor. He taught that hardwood cleats were the prefered fastener, better hold and they allows some movement.

Another trick with 1-3-4" long cleats was to put a 3/4" block under the rear of the nailer. This drove the cleat at a shallower angle, so it could not reach the tube. Still plenty of hold with the serated cleats.

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