Tracer gas (5% hydrogen in 95% nitrogen) is introduced into the pipework at low pressure. The gas rises harmlessly through screed, timber, tile or concrete and is picked up by our gas sensors at the exact point of escape.

What's included

Finds leaks too small to hear acoustically
Works on pressurised and unpressurised systems
Non-flammable, non-toxic, food-grade mix
Essential for underfloor heating diagnostics

Technology used

Hydrogen/nitrogen tracer gas

Pricing

Fixed, all-inclusive fee — confirmed in writing before the visit. Most domestic jobs fall between £275 and £595. Commercial and underground mains work is quoted individually. No hourly creep, no hidden call-out fees.

Is this covered by my home insurance?

Yes — almost all UK buildings policies include a Trace & Access allowance (typically £5,000). We provide the formal report your insurer needs to release funds. See the insurance claims guide.

Related services

Other leak investigations we handle

Hidden Water Leak Detection

Find leaks behind walls, under floors and above ceilings — without demolition.

Central Heating & Boiler Leaks

Boiler losing pressure? We find the leak in the system without lifting your floors.

Underground Mains Leak Detection

Locate leaks on the buried supply pipe between the street and your property.

Frequently asked questions

№ 01Can you find a leak without damaging my walls or floors?

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Yes. Every one of our surveys uses non-invasive equipment — thermal imaging cameras, acoustic listening devices, moisture meters and tracer gas. We locate the leak first, then open only the precise area needed for the repair, saving you hundreds in reinstatement costs.

№ 02How long does a leak detection survey take?

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Most domestic surveys take between 2 and 4 hours. Complex cases — underground mains, heritage buildings or commercial risers — can take a full day. We confirm the expected duration when you book so there are no surprises.

№ 03Is leak detection covered by my home insurance?

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Almost all UK home insurance policies include 'Trace & Access' cover under the Escape of Water section — typically up to £5,000. We write the report your insurer needs to release those funds. Ask your insurer for the trace-and-access limit on your policy before you book.

№ 04What is a Trace & Access report and why do I need one?

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It's a formal written report that documents how the leak was located and what was required to access it. Insurers (Aviva, Direct Line, Admiral, AXA, LV=, Lloyds and others) routinely ask for one before they reimburse investigation or repair costs. We prepare it as part of every survey at no extra charge.

№ 05Do you offer a 'No Find — No Fee' guarantee?

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Yes, on standard domestic internal hot and cold pipework leaks, where the leak has already been narrowed to a single room or area no larger than 5m × 5m, and where we're authorised to carry out the exposing repair on the same visit. We'll confirm eligibility during your enquiry — this guarantee doesn't apply to heating systems, drains or mains supply pipes.

№ Final —

Think you have a leak? Don't let it do more damage.

Fixed-price, insurance-ready surveys across London. Most bookings surveyed within 24 hours.

Request a survey

Tracer Gas Leak Detection