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Croxley Green, Three Rivers

Leak detection in Croxley Green

In an extended Croxley Green home, the leak could be under the old timber boards or in the new concrete floor. We find which part is losing water, then trace it.

Underfloor heating loops tested singly

Timber and concrete floors

Leaks marked and photographed

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Lines open 8am to 8pm, every day.

Croxley Green's interwar houses were built with suspended timber ground floors: boards laid on joists above a ventilated gap. Since then, many have gained an extension on a new concrete floor, often warmed by underfloor heating laid in its screed, the smooth top layer of the floor.

That leaves two floors with different habits. A pipe under the old boards can drip into the void for months; one in the extension's screed shows as a falling boiler gauge or a warm tiled strip. Leak detection in Croxley Green begins by deciding which to search.

1930s mock Tudor semi-detached houses with hedged front gardens on a frosty morning, typical of a Hertfordshire commuter town White rendered Arts and Crafts cottages behind hedges and wide grass verges, typical of a Hertfordshire garden city

Two jobs typical of Croxley Green

Pressure loss traced to the pipes feeding the manifold

The property

An interwar semi with an underfloor-heated extension. The boiler stays in the old house, and two pipes from it cross the new screed to the manifold, the cupboard of valves for each loop.

The problem

Refilling the boiler had become a twice-weekly job, yet nothing looked wet. Their builder blamed a failed loop, and the owners feared for the new porcelain floor.

How we found it

Each loop, closed off at the manifold, held pressure, so the floor loops were sound. The camera then followed the two feed pipes across the screed to warmth spreading off one of them, and tracer gas agreed.

The outcome

Two tiles over the joint were marked and photographed. The repair, quoted separately, was done on the day, and the owners filed our report with the extension's paperwork.

Hall ceiling stain below a shower over the bath

The property

An interwar semi with its bathroom over the hall. The shower runs over the bath behind a hinged glass screen, above the original timber boards.

The problem

A brown stain on the hall ceiling grew after every shower but never after a bath. A plumber had replaced the bath waste, and still it returned.

How we found it

Readings below peaked under the tap end. Filling the bath changed nothing, but spraying the shower at the screen's hinge did, and a moisture meter read wettest along the bath edge there.

The outcome

The gap was in the seal under the screen, not a pipe. We marked and photographed it, and the owner had it resealed without lifting a tile or board.

System, then section, then spot

1

Which system is leaking

Mains supply, hot water and heating each get their own test: the meter checks the supply and hot water, and a pressure gauge checks the heating.

2

Which length of pipe

Within that system, valves let us test sections or loops one by one, which usually shows whether to search the old floor or the new one.

3

Which exact point

Our engineer Charlie then traces that length with the method that suits the floor, and a second method checks the result before the spot is marked.

Croxley Green callers, and what they need

Extensions with underfloor heating

Pressure keeps dropping, yet no damp shows. Working from the manifold, we shut the loops off one at a time and follow whichever fails, so tiles come up only where we mark.

Owners whose leak turns out to be indoors

A water company letter sent you searching the garden, but the meter stopped when you closed the stop tap. The leak is indoors, usually under a floor, so we trace it there.

Anyone with a stain under a bathroom

A mark on the hall or kitchen ceiling grows after the bathroom is used. We take moisture readings, then try each fitting on its own to see which one wets it.

How the methods suit two kinds of floor

Pressure testing

Each loop or section is closed off and watched on a gauge, the quickest way to tell a leaking underfloor loop from a sound one.

Thermal imaging

Warm water shows through tiles and screed, so a running underfloor loop appears as clear lines. Through carpet and boards the picture is weaker, so there we pair it with another method.

Acoustic listening

Mains water escaping under a timber floor or garden path makes a steady hiss. A ground microphone on the boards or the ground finds where it is loudest.

Affinity Water letters when the leak is indoors

Affinity Water supplies Croxley Green. Its letter about constant flow means water is passing your meter, not that the leak is in the garden. The pipe from the boundary or meter onwards is usually yours, indoors and out. Shut your stop tap: if the meter then stops, the water is escaping indoors.

Insurance and the tiles that come up

If your policy covers tracing a hidden leak, expect the insurer to ask why the floor was cut where it was. Our report explains it: the location, methods, readings and photographs behind the marked spot, which is where opening up should begin. Until it is exposed, a leak is not proven.

Beyond Croxley Green

Rickmansworth and Watford sit either side of Croxley Green, with Chorleywood further west along the Metropolitan line. Beyond Watford, our leak detection in Hertfordshire also covers South Oxhey, Carpenders Park and Bushey.

Timber-framed and brick cottages beside a village pond with a willow tree, typical of a Hertfordshire village

Common questions in Croxley Green

No. We find the losing loop, then the point on it, and mark that spot, which is all that needs opening. Pipes laid in insulation, ducting or beneath a membrane are harder for any method, so tell us how the floor was built.

The pipework is losing water, often somewhere under a floor. Before ringing, note how many times a week you refill it and whether any leak sealer went in. Each part of the system is then tested separately to see which leaks.

No. Underfloor heating counts as central heating, which no find, no fee on home water leaks does not cover. Instead the price is set before booking, for a half day of testing or a full one. Full conditions are on our terms page.

We can usually book a visit within 24 to 48 hours. When you ring, tell us whether your home has an extension and underfloor heating, and where the manifold and stop tap are, so we come prepared for both floors.

It helps. Warm pipes are what the thermal camera picks up, so run the heating beforehand if you can. If the boiler cannot hold pressure long enough to run, say so when you book, and we begin with pressure testing.

Leak in a Croxley Green semi?

Ring 07700 102 008 and tell us about any extension or underfloor heating.