Two leaks. One thorough investigation.
A smell of gas beneath a staircase led to emergency isolation, followed by a detailed investigation by TNG Services Ltd. The work uncovered two leaking joints in old black iron pipework, alongside separate sleeving and bonding defects.
Bushey, HertfordshirePipework repairs & corrective work
A Sunday evening smell of gas
The customer contacted TNG Services Ltd after noticing a smell of gas coming from beneath the staircase at their home in Bushey, Hertfordshire WD23.
We immediately advised them to turn off the gas supply at the meter if it was safely accessible, and to call the National Gas Emergency Service on 0800 111 999.
- Emergency adviceThe customer was directed to the National Gas Emergency Service.
- Cadent attendanceCadent attended and isolated the gas supply.
- Next-day investigationTNG Services reviewed Cadent’s report and took over the leak investigation and repair work.
Following that review, our engineer temporarily reinstated the supply under controlled conditions for testing and leak tracing. This was part of the professional investigation; the customer should not turn an isolated gas supply back on themselves.
Act immediately, even if the smell is faint
- Call 0800 111 999 immediately from a safe place outside.
- Open doors and windows to ventilate the property, if safe.
- Turn off the gas at the emergency control valve beside the meter, if safely accessible. Do not enter a cellar or basement to reach it.
- Do not smoke, light matches or use naked flames.
- Do not turn electrical or light switches on or off, or use appliances that could create a spark.
- If the smell is strong, you feel unsafe, or the suspected leak is in a cellar or basement, leave the property immediately.
- Follow the emergency operator’s instructions. Do not turn the gas supply back on yourself.
The first leaking joint was not the whole problem
The initial investigation identified a small leak at an existing black iron gas pipe tee joint above the floorboards in the staircase area.
Further investigation beneath the floorboards revealed a second, major leak at another connection in the old black iron pipework. Finding it highlighted why the investigation needed to continue beyond the first leaking joint.
Replacing the defective section
The faulty section of gas pipework was removed and replaced with a new copper pipe section, connected to the remaining existing steel gas pipework.
An unprotected gas pipe wall penetration
During the works, we found that the existing copper gas pipe from the meter passed through the wall without a protective sleeve, with mortar touching the pipe directly. This was a separate installation defect requiring correction.
A suitable sleeve separates the gas pipe from the masonry, helping protect it against abrasion and stress caused by movement. Where a pipe passes through a cavity wall, correctly installed sleeving and sealing also help prevent escaping gas from entering the cavity.
Does mortar touching copper always cause corrosion?
No. Contact with mortar does not automatically cause corrosion. However, moisture and aggressive contaminants in surrounding materials can contribute to it. Rigid mortar can also restrict movement and place stress on the pipe.
Over time, corrosion or mechanical damage may weaken a pipe. These were potential risks of the unprotected wall penetration, separate from the two leaking connections identified during this investigation.
We corrected the wall penetration by installing protective sleeving.
Missing gas bonding corrected
Gas bonding was also absent at the meter. We added protective equipotential bonding to the gas pipework.
This is an electrical safety measure intended to reduce dangerous voltage differences between metal services during an electrical fault. It was an additional corrective task, distinct from repairing the leaking gas joints.
Making good and final testing
Once the repairs and corrective works were completed, the wall was made good and the floorboards were reinstated as neatly as possible.
All completed work was tested, with the customer present to witness the final testing. The project covered two gas leaks, replacement pipework, wall sleeving and protective bonding.
Gas leak investigation and repairs in Bushey
TNG Services Ltd provides gas leak investigation and repair services in Bushey, the Watford area and across Hertfordshire. If your supply has been isolated following an emergency attendance, contact us to arrange investigation and the necessary remedial work.
For official emergency guidance, see Cadent: what to do if you smell gas.