Be sure to find a tile installer who is well versed in waterproofing. The John Bridge Tile Forum will get you educated in this repair so you can wisely choose a good contractor.

Yes I agree with you the mat must be leaking current in order to produce this effect. Unfortunately the cost of materials is so low compared to the cost of installation. I imagine if we go further with the troubleshooting we will reach a point where it's impossible to prove whether the mat is defective or if it was damaged from install, without ripping the whole thing out. The contractor was present when mat was installed and claims it was not damaged. The manufacturer is unlikely to warranty anything without proof of that which would presumably entail removing the floor. So that would mean we'd be paying a lot more for labor to have the issue diagnosed. I think we want the contractor to finish the kitchen work (install sink, DW hookup and backsplash) and then we'll have them cap off the system and abandon it. It's on its own breaker so it's not a risk right now. I will not expect to be charged for the install, I can return the thermostat and I'll be out $200 for the mat itself worst case scenario. If I need to get an electrician in there to separately confirm that it's most likely an install issue (ie if contractor charges me for install), I will. There were no extra leads, the mat came with the wires attached. We turned on the floor about 7 days after install when we moved back in, no one instructed us otherwise. I did see in the instructions online later to wait 28 days. I figured that is to allow mortar to set avoid cracking etc, but I didn't see that info until I watched the video after getting the shock. Lesson learned, if you want something like heated floor get an installer who has experience with the product.

I've read all of your posts over and over again, and am still unsure about how to approach this. There are many opinions, and i couldnt even get a clear answer from the contractors i had come out. The guy who came out friday told me to excavate and fix the problem from the outside as some of you told me. He said i ONLY need to do the problem walls. He doesnt recommend me doing the 'bone dry' north wall. He would do the west wall and any other wet walls once we open them up and see. I dont understand this, why would i just excavate the wet cinderblock walls when even in the bone dry cinder block wall the insulation was soaking wet. Who's to say once i get it done and i end up with bone dry cinderblock walls all end up with wet insulation. Since ive opened up the wet wall its 90% dried out. Even with heavy storms lasting two days its drying out. Doesnt this mean it is condensation?? I came across a video (and a QnA) of holmes in homes, he uses rigid insulation and seals it with tuck tape on the concrete walls, and puts the studs up against that, doesn't put any batt insulation inbetween studs, he does this on the floors too. This is his way of keeping moisture out. He doesnt put a vapor barrier up... he said batt insulation is the worst thing you could use in a basement because of the way it holds moisture, and mold. I do apologize for continuing to bother you guys, 10-15k excavation job is a very pricey approach for us, and want to be absolutely sure its the way we want to go. Pictures below show where its at and where it was. (I had opened more of the wall up)

If you are paying $800 a month for utilities I think you need to better decipher where, what and how those costs are inflating your utility bill. A utility rate of 30 cents per KWH is only part of that monthly bill. The idea here is to suggest that a leaky house may only play a very minor role in that utility bill. Why? I live in a leaky house now, my electric bill was $51 at 11.6 cents per kwh. I recently installed an Inverter 18 SEER heat pump at my house. The attic of the house has also been re-insulated. But I didn't do anything crazy like sucking out old insulation etc. Nor did I spend any time trying to seal cracks and crevices. Primarily because I want the house to 'breathe' a little. I have started replacing windows but nothing high end. These are just low e, gas filled double pane windows -- BG from Home Depot, Nothing special. ------------ So why do this... why try to cut the utility bill? Mainly because there is 'head room' within that bill. Head Room = High bill. How high is high? $800 a month. In my case --- it was no where near $800 a month. But I live in a 11.6 cent use area. So as an example if I burned 500 KWH at .30 cent rate my bill would be $150 a month. --- I use that as an example. My last light bill was $51. So what do those figures tell you? --- there is a lot of head room between $800 a month and $150 a month. (You know as in a comparable home to mine, with similar things done to it. It's 1910 sq. ft. btw) Find what is 'contributing' the most to that $800 a month spend? The easiest are light bulbs. Are you still using incandescent light bulbs? Florescent? LED's have come a long way. Start there --- replace all those light bulbs to LED. In California you probably don't have very high use in HVAC. But you need to see or some how determine exactly or close to it as to what it is costing you to run it. Simple --- take your monthly bill from a month with little to no heating or AC usage. A month like March or April for example compared next to an August bill. That should tell you something. ( I doubt heating costs are that high in SF bay area --- so it's not likely to benefit you unless you are in all electric home, in that case you need to upgrade to a Inverter Heat pump) Other energy robbing offenders: pool. If you have a pool at your house that thing is a energy drain. Those pool pump(s) -- have to run to clean the water via filtration. A pool pump here costs at least $150 a month at around 11 cent a KWH. Times that by three for California. --- if that's the case, that is half your bill right there. It comes down to 'USE'. Remember that. Pool pumps tend to run 24/7. People give them little thought as a energy robbing offender. Sticking an old refrigerator or two in the garage and maybe a freezer. -- why is this a thing? The gaskets on the doors of these is probably worn. Not to mention an older appliance is very energy inefficient. _________ Notice what I say here has little to do with a 'leaky' home. After you investigate.... tell us what you find. It's worth it if you are paying $800 a month in utility bill.