When Latex Paint Forms 'Bubble' Evidence of HOT Water Leak?

[Lovegasoline]

I'm an apartment dweller. I have an intermittent leak coming from my ceiling. Unlicensed plumbers have come but cannot find the source. One area on the wall the leak was evidenced by distortion of the paint ... it is sagging and had formed a 'bubble'... then it receded with evidence of the latex paint stretch marks. One of the plumbers said that only a HOT WATER leak will cause latex paint to distort of form a bubble like that.

Is this true?
Can one rule out cold water as a source of the leak?

Thanks a bunch.

 

[Caduceus]

Any water will cause the bubble that you have described. The bubble is the latex part of the latex-based paint. Leaks can be very tricky to chase down. They could come from roof shingles, roof flashings, window trim, toilets, sinks, tub/showers (especially if the shower curtain is left out of the tub), shower heads and diverters...the list goes on.
If this is a rental, I'm surprised that the landlord hasn't consulted a professional leak search company to find the leak, to preserve the integrity of the structure.
When a leak has been discovered it may have already done some serious damage that cannot be seen yet.
In my area American Leak Detection are the go-to guys for difficult searches. They have the technology to see or hear where the water is coming from without ripping a house in half...well, most of the time...but sometimes getting invasive is the only way to find the problem.