· Michael Blair
Sudden failures get dealt with. What costs more, and is usually excluded by insurers as gradual damage, is the slow leak that runs for months behind a wall or under a floor.
What to look and smell for
A musty smell with no visible source is the most reliable early indicator, because mould establishes before staining appears on the finished surface.
Then: paint or wallpaper bubbling, a patch of wall that is cooler to the touch, floor that flexes underfoot, and grout or caulk that keeps failing in the same spot.
- Musty smell with no visible cause
- Bubbling paint or lifting wallpaper
- A cool or damp patch on a wall
- Flexing or cupping flooring
- Caulk or grout failing repeatedly in one place
- Water bill rising with no change in use
Use the water meter
Turn off everything using water, note the meter reading, and check again in an hour. Movement with nothing running means a leak somewhere on your side of the meter.
It is the single most useful diagnostic a homeowner has and it costs nothing.
The usual locations here
Under kitchen and bathroom sinks, at the washing machine supply hoses, behind the dishwasher, at the water heater, and at the toilet supply and wax seal.
In Middle Tennessee, add the crawl space: a leak there can run for a very long time before anything is visible upstairs.
Why gradual damage is a problem
Most policies cover sudden and accidental discharge and exclude damage from a leak that was ongoing. A slow leak found late can therefore be both expensive and uninsured.
That is the practical argument for checking the crawl space and under sinks a couple of times a year.