Blocked drains and toilets are a common nuisance for homeowners and construction sites alike. Understanding the causes, prevention, and solutions is essential for maintaining a functional and efficient plumbing system. This guide explores the common reasons behind blockages and provides practical steps to resolve and prevent them.

Understanding the Causes of Blocked Drains

Drains can become blocked for a variety of reasons. Knowing the different types of drains and what causes them to clog will help you in the long run.

• Blackwater drains carry sewage from toilets and should be connected to a septic tank or a government sewer system.
• Greywater drains carry wastewater from kitchen sinks, washing machines, showers, and washbasins and should also connect to a septic tank or sewer.
• Rainwater drains direct water away from your property and can be discharged into absorption pits, flood drains, or roadside drainage channels.

The most common causes of blockages include:

• Tree roots: In the past, tree roots were a major cause of blockages in older ceramic pipes. These pipes were connected with rubber O rings which would leak and attract tree roots. . However, with the use of sealed or welded plastic pipes, this issue has become less common.
• Construction debris: Sand, soil, leaves, cement, and other debris can enter and clog drains, especially during construction or renovation projects.
• Improper disposal: Flushing non-degradable items such as wet wipes, nappies, sanitary items, condoms, and cotton buds down the toilet is a major cause of blockages. These items do not break down naturally and can easily get caught in pipes.
• Fats, oils, and grease (FOG): When poured down the drain, FOG can solidify and mix with other substances, forming a soap-like substance that is difficult to remove. This process, called saponification, contributes to the formation of large blockages known as “fatbergs”.
• Hair and food waste: These can accumulate in pipes, causing blockages over time.
• Toilet paper habits: Using excessive toilet paper and scrunching it into a ball instead of folding it can also lead to blockages.

Prevention is Key

Preventing blocked drains is easier and more cost-effective than dealing with the aftermath. Here are some crucial preventative measures:

• Avoid flushing non-degradable items: Never flush wet wipes, nappies, sanitary products, condoms, or cotton buds down the toilet.
• Be mindful of toilet paper use: Avoid scrunching toilet paper into large balls. Instead, fold it or consider using a water spray washer.
• Properly dispose of fats, oils, and grease: Do not pour cooking oils or fats down the kitchen sink. Collect them in a container and dispose of them properly.
• Regularly clear gutters and drains: Remove leaves and other debris from gutters, downpipes, and drains to ensure proper flow.
• Prevent construction debris: Do not let soil, sand, or cement wash into drains.
• Consult with professionals: Engage a qualified plumber or MEP engineer to design and advise on black, grey, and rainwater installations.
• Install U-bends: Install U-bends on floor and shower drains, washbasins, and kitchen sinks to trap debris and prevent sewer odors. Toilets typically have a built-in U-bend.
• Ensure proper drain sizing and slope: Use 4-inch diameter pipes for toilets and 2-inch pipes for greywater. Also, make sure drains have sufficient slope to allow water to flow correctly.
• Use round-bottom drains: Round-bottom drains concentrate water flow, which helps to keep them clean. Minimize bends in the system and use 45-degree bends instead of 90-degree bends where possible.
• Install cleanouts: Provide access points in drains to allow for pipe cleaning equipment.
• Use grease traps: Install and regularly clean grease traps in restaurants and cafes to prevent fats, oils, and grease from entering the drains.

How to Unblock Drains

If you encounter a blocked drain, several methods can be used to clear it. Start with the least invasive approach:

• Plungers: Use a plunger for small blockages near the drain opening in sinks, washbasins, toilets, and floor drains. A plunger can provide a temporary fix.
• Hand pumps: Hand pumps can generate more pressure than plungers for stubborn blockages.
• U-Bend cleaning: Check and clean U-bends under sinks and washbasins. They can accumulate debris that cause blockages. Remove and clean them or remove the drain cover for floor drains.

If these methods fail, more advanced techniques are required:

• Chemical drain cleaners: Use chemical drain cleaners with caution. They are effective for small blockages but are dangerous and can damage pipes and harm the environment. It’s best to avoid using them.
• Snakes and Augers: Plumbers use augers and snakes to clear blockages in pipes. Augers are for straight pipes, while snakes can navigate bends.
• Drain cleaning machines:
  • Water jetting equipment: These machines use high-pressure water to clear blockages and even cut through tree roots. They are best for outdoor drains.
  • Rotary steel snake machines: These machines rotate a snake to clear blockages far from the drain access point.
• Digging out the pipe: If all else fails, you may need to dig out the blocked pipe or install a new one.

Final Thoughts

Dealing with blocked drains and toilets can be a frustrating and potentially costly issue. By understanding the causes of blockages and taking preventative measures, you can minimize the risk of plumbing problems. If you encounter a persistent blockage, it is important to seek help from a professional plumber to ensure the problem is resolved properly and safely.