I don’t think there was a septic tank but I really don’t have a way to know…one way or the other. As a test, before going to bed, I turned everything off - including water heater and heat pumps. Next morning, there was still a 12 degree difference between the warm spot and the rest of the garage floor. That’s exactly the same difference from the night before. It doesn’t change in response to anything I’ve tried.
I’m very tempted to get a jack hammer and see what’s going on.
No one else has seen this before?
Thanks for your feedback.
Greg Sullivan / Canyon Lake, CA.
Althought uncommon, soil composition can generate high temperatures. What part of Canyon Lake are you in? Any chance there’s high alkali content in the soil under your structure? Have you noticed any spalling and or efflorescence developing in the garage concrete slab surfaces? Do fresh water and or main waste line plumbing run under the garage slab?
Before busting up the floor, use a regular contact thermometer to verify the temp difference. The infrared temp gun’s emissivity reading is effected by the amount of reflective surface. Its possible that there was some oil or other chemical spilled there once affecting the reading. The amount of reflective change is not always enough to be noticeable by the eye.
If you ever tried to use an infrared temp gun to take a reading on a galvanized plenum you know what I mean. I use 4"x4" magnetic sheet to stick on the plenum first and give them enough time to reach the same temp as the plenum before taking the reading.
Is it possible it is just a void? Did you try tapping on the floor with a light hammer to hear for sound difference. Would a void have a different temperature than surrounding cemment?
Could it be something stupid, like the Code Enforcement did not allow a floor drain in the garage for that area and it was capped and poured over with the concrete floor.??
Isn’t Canyon Lake where they spread the soil from the Area 51 test wells? Could be an alien head or body part. Ooh Ooh…maybe its a buried stargate… …Phaser fire from an alternate / parallel universe. Wait wait…If you dig it up, it might look like the Virgin Mary…thats good on ebay for at least $5k.