Blocked Sinks & Basins in Dorchester

Slow is a warning, not a quirk

A sink that takes a minute to empty is already partly blocked. The restriction builds gradually, so it is easy to get used to, until the day it stops entirely, usually when the house is full of people.

Other early signs are a gurgle as the last of the water leaves, a ring of grey residue that keeps coming back, and a sour smell from the plughole. In a shower, water pooling around your feet before the end of a shower means hair has already narrowed the trap. All of these are easier and cheaper to deal with before the waste stops altogether. Call straight away if dirty water rises into the sink when nobody has run a tap, or if the gully outside the kitchen is overflowing, because both mean the blockage is in the drain.

What causes a kitchen sink to block?

Kitchen sinks block mainly with cooled fat, oil and food residue that set hard against the inside of the waste pipe. Each wash adds a thin layer until the pipe closes.

Fat poured away hot looks like liquid, but it cools within a short distance of the plughole and sticks to the pipe wall. Starchy food such as rice and pasta, coffee grounds, and the fine grit from washing vegetables bind into it. Dishwashers and washing machines plumbed into the same waste add detergent residue and lint. Washing-up liquid helps fat travel a little further, but it does not stop it setting somewhere down the line.

What causes a bathroom basin, bath or shower to block?

Bathroom wastes block mainly with hair bound together by soap, toothpaste and conditioner. The mix forms a stringy plug that catches everything that follows.

Basins collect hair, toothpaste and the gel from shaving products, and the overflow channel inside the basin gathers its own slime. Baths and showers take far more hair, and shower traps are often shallow with small, awkward access, so they clog quickly. Hard water adds limescale to all of it. Kitchen and bathroom blockages need different treatment, and pouring a kitchen product down a bathroom waste rarely does much.

What is the U-bend, and why does it block?

The U-bend, or trap, is the curved section of pipe under a sink that holds a small amount of water. That water forms a seal that stops drain smells coming back into the room.

Because the trap changes direction and holds water, it is where heavy debris settles first. Most basins and sinks have either a U-shaped trap or a compact bottle trap, both of which unscrew by hand for cleaning. Shower and bath traps are smaller and often hidden behind a panel or under the tray, which is why they are harder to reach. A blocked trap is usually the easiest kind of blockage to clear.

When it is not the sink at all

If more than one fitting is slow at the same time, the problem is usually further down the system rather than in any single trap. That is worth knowing before anyone dismantles the pipework under your kitchen units.

A kitchen sink and a dishwasher backing up together suggests the shared waste pipe or the gully outside. A basin, bath and toilet all slow on the same floor points to the soil stack or the drain it feeds. If the outside gully under the kitchen waste is full or overflowing, the blockage is there or beyond it, not under the sink.

How can I unblock a sink myself?

Plunging and cleaning out the trap clear most simple sink blockages, and both are safe to try. Start with the plunger, because it does not involve taking anything apart.

• Remove the plug, strainer or pop-up and pull out any hair or debris you can see
• Block the overflow hole with a damp cloth so the plunger can build pressure
• Run a few centimetres of water, seal the plunger over the plughole and pump firmly
• If that fails, put a bowl under the trap, unscrew it by hand and clean it out
• Refit the trap carefully, making sure the washers sit flat, then run the tap and check for drips

If the water still will not drain after the trap is clean, the blockage is beyond it in the waste pipe or the drain.

Should I use chemical cleaners or boiling water?

Chemical drain cleaners and boiling water are both best avoided. Chemicals rarely clear a full blockage and are dangerous to handle, while boiling water can soften or distort plastic waste pipes and joints.

Caustic soda and similar products can eat into a thin layer of fat or hair, but on a solid blockage they sit in the trap and make it hazardous for whoever dismantles it. They can also damage some older metal pipework and seals. Hot water from the tap with washing-up liquid is a safer way to loosen light fat. Boiling water poured into a ceramic basin or sink can also crack it.

How we clear a blocked sink, step by step

We find where the blockage is first, then clear it at that point. Most sink jobs are solved at the trap or in the waste pipe, but we check the outside gully or stack before taking anything apart.

• We check which fittings are affected and look at the gully or chamber outside
• If it is local, we clear the trap and waste pipe by hand or with a small drain cable
• If it is further down, we clear the stack or drain from the appropriate access point
• We refit everything and run water through to check flow and look for leaks
• We explain what caused it and how to avoid a repeat

If we find something that needs more than a clear, you get the reason and the price before we go on.

How long does it take to unblock a sink?

A blocked trap or a short waste pipe is usually cleared well within an hour. A blockage further along, in the stack or the drain outside, takes longer.

What adds time is access: traps hidden behind fitted kitchen units, baths with tiled-in panels, and shower trays with no access to the trap from above. Long horizontal waste pipes with hardened fat along their length can take a while to clear properly, and we would rather clear them fully than leave a narrow channel that blocks again.

How much does it cost to unblock a sink?

The price for a sink comes down to where the blockage sits and how easily we can reach it. There is no call-out fee, and you get a fixed price to agree before anything is taken apart. As a guide, unblocking a sink typically costs £60 to £150.

A blocked trap that comes apart easily is the quickest job. The price rises when the blockage is in a long waste pipe, the soil stack or the drain outside, when panels or kickboards need removing for access, or when the waste pipe itself needs replacing. If the job changes once we are working, we stop, show you and agree a new price first.

What sink unblocking can and can't fix

Unblocking clears what is in the trap, waste pipe or drain. It cannot correct a waste pipe laid with too little fall, a cracked trap, or a pipe badly scaled inside.

A waste that sags or runs nearly level holds water and lets fat and food settle, so it blocks again however well it is cleared. A pipe that is too small for a dishwasher and sink together can struggle at busy times. Where we find one of these, we explain what would fix it, which is sometimes replacing a section of waste pipe, and price it separately.

In a home you own, the sink, its trap and the waste pipe are your responsibility. Only a blockage in a drain shared with neighbours, or in the public sewer, would fall to Wessex Water rather than to you.

How to stop a sink blocking again

Keep fat and food out of the kitchen sink and hair out of the bathroom ones. Those two habits prevent most of the sink blockages we see in Dorchester homes.

• Wipe greasy pans with kitchen paper and bin it before washing up
• Let cooking fat cool, then put it in the bin
• Use a fine strainer in the kitchen sink and a hair catcher in the shower
• Unscrew and rinse basin bottle traps every few months
• Run hot tap water for a minute after washing up to move residue along

If a sink still blocks regularly with good habits, the waste pipe's fall or the drain outside is worth checking.