Do slow-draining sinks always mean a blocked drain? +
Not always. A slow-draining sink is often caused by a localised blockage in the waste trap or the pipe immediately beneath the sink — hair, soap scum and grease are common culprits. However, if multiple fixtures are draining slowly or you notice gurgling sounds, the problem is likely further down in the main drain. A drainage engineer in Cardiff can distinguish between a simple waste pipe blockage and a more serious drain issue.
What causes a foul smell from my drains in Cardiff? +
Foul drain smells are usually caused by a dried-out trap (the U-bend), a cracked or disconnected pipe, or a blockage building up in the system. If the smell is coming from outside, it could indicate a broken manhole cover seal or a collapsed section of drain. Run water through any infrequently used sinks or showers to refill their traps first. If the smell persists, a CCTV drain survey will identify the cause.
What is the difference between a drain and a sewer? +
A drain serves a single property and runs from your house to the boundary. A sewer carries waste from multiple properties and is maintained by the water company. Lateral drains — the section connecting your drain to the public sewer — transferred to water company responsibility in October 2011. Understanding this distinction matters because it determines who pays for repairs.
Can I unblock my own drain or should I call a professional? +
Simple blockages near plugholes can sometimes be cleared with a plunger or drain snake. However, if you have sewage backing up, multiple drains blocked at once, or persistent foul smells, you should call a professional drainage engineer in Cardiff. Using chemical drain cleaners on severe blockages rarely works and can damage older clay pipes. Professional high-pressure jetting is far more effective and safer for your drainage system.
What should I do if my drain is overflowing outside? +
If an external drain or manhole is overflowing, check whether it is a shared drain serving multiple properties. Since October 2011, lateral drains and public sewers became the responsibility of your water company, so contact them first if the blockage is beyond your property boundary. If it is a private drain within your boundary, call a drainage engineer in Cardiff to clear the blockage.
What is the NADC and why does it matter? +
The NADC — National Association of Drainage Contractors — is the leading UK trade body for drainage professionals. NADC members must demonstrate competence, carry appropriate insurance, and adhere to a code of practice. Choosing an NADC-registered drainage engineer in Cardiff gives you confidence that the work will be carried out to professional standards with proper equipment.