Warm Spot on the Floor? A Hot Pipe Is Leaking

Heating pipes under a floor lose a little warmth along their whole length, which is why a floor over a pipe run can feel faintly warm in winter. A single spot that is noticeably warmer than the rest is different. Hot water escaping from a split or a joint spreads out under the floor and warms the tiles, boards or laminate above it, often with a damp edge you only notice later. On a floor with underfloor heating, the same thing shows as one area running hotter than the loops around it.

In the solid-floor semis around Watford, Bushey and Harrow, heating pipes were often buried straight into the screed with no sleeve, and forty or fifty years later the copper corrodes where it touches the concrete. In Victorian and Edwardian terraces the pipes run through the void under a suspended floor and a leak warms the boards above it. In newer homes and extensions with underfloor heating, the problem is usually a pipe damaged during a later fitting, a joint under the screed, or a loop that has failed near the manifold.

This is where thermal imaging earns its keep. With the heating running we scan the floor and the camera shows the pipe routes as warm lines and the leak as a bright bloom where hot water is spreading. To confirm the exact point before anything is cut, we pressure test and use hydrogen tracer gas so the spot we mark is the spot we open. The thermal images, readings and photographs go into your written report, and we can repair the pipe through that one opening on the same visit.

Because a leak like this has usually been soaking the floor for weeks, it is a common trace and access claim. Buildings insurance normally covers locating the leak and reinstating the floor we open; the pipe repair is usually charged separately. The thermal images in our report are exactly what a loss adjuster wants to see.