What Causes Drain Blockages? How to Prevent Them for Good
What Causes Drain Blockages — and How to Prevent Them for Good
Blocked drains are more than an inconvenience — they can damage pipework, cause foul smells, and lead to costly repairs if left untreated. In this guide, the team at P A Henery Ltd explains the most common household causes of blockages, easy ways to prevent them, and when to book a CCTV drain survey for peace of mind.
The Most Common Causes of Blocked Drains
- Fats, oils & grease (FOG): Cool and harden in pipes, creating sticky deposits that trap debris.
- Food waste & coffee grounds: Settle in traps and bends, especially in kitchen lines.
- Hair & soap scum: Bind together in bathroom waste pipes and shower traps.
- Scale (limescale): Narrows pipe diameter and roughens surfaces so debris clings and builds up.
- “Flushable” wipes & sanitary products: Don’t break down like toilet paper and cause persistent blockages.
- Leaves, silt & roof debris: Enter gullies and external drains, restricting flow during heavy rain.
- Tree roots: Seek moisture, enter small cracks and expand, obstructing or breaking drains.
- Damaged or misaligned pipework: Collapsed sections or poor falls create snag points where waste collects.
How to Prevent Blockages (for Good)
Kitchen habits: Let fats cool and bin them, wipe greasy pans with paper before washing, use a sink strainer. Avoid disposing of coffee grounds in the sink.
Bathroom habits: Fit hair catchers in showers, bin wipes/cotton buds/floss, and periodically run hot water to clear soap residue.
Outside maintenance: Keep gutters and gullies clear of leaves; check covers after storms; trim roots near drainage lines.
Service & surveys: If blockages repeat or you notice slow drains and smells, book a CCTV drain survey to diagnose hidden issues. For repairs and one-off cleans, see our Drainage Services.
When Should I Book a CCTV Drain Survey?
- Recurring blockages in the same location.
- Persistent smells, damp patches, or gurgling pipes.
- Before buying, selling, or renovating a property.
- Evidence for insurance claims after flooding or subsidence.
- Mature trees close to drainage lines.
Myth-Busting: Drains Edition
- “Flushable wipes are fine.” Myth — most don’t break down and are a leading cause of blockages.
- “A bottle of drain cleaner fixes everything.” Myth — harsh chemicals can damage pipes and only clear soft obstructions.
- “Pouring boiling water in the toilet clears blockages.” Myth — it can warp or crack porcelain; use safe methods or call a pro.
- “Rodding always works.” Myth — rods can compact a blockage or damage joints if the cause is structural.
Signs You Need a Professional
- Multiple fixtures backing up at once (e.g., toilet and bath).
- Water rising in external gullies or inspection chambers.
- Frequent slow draining after DIY attempts.
- Bad smells that return within days of clearing.
Drainage Services Emergency Call-Outs
Key Takeaways
- Most blockages are preventable with good habits and simple maintenance.
- Wipes, FOG, hair, and scale are the most common household culprits.
- Use a CCTV drain survey to diagnose repeating issues or when moving home.
- Call professionals for persistent or multi-fixture problems to avoid pipe damage.
Talk to a Drainage Expert
From fast unblocking to detailed CCTV surveys and long-term repairs, P A Henery Ltd has you covered across South Croydon and surrounding areas.