Clearing Blocked Bath and Shower Drains

Slow draining or blocked shower and bath drains are a common problem that our drainage engineers are called on to resolve throughout London.

Blockages are most commonly caused by clumps of long, tangled hair mixed with grease from soap plus other debris and dirt. The build-up of lime scale can also reduce the flow of water draining from a bath or shower. This can add to blockage problems.

Sometimes using a regular plunger can clear whatever’s causing the blockage. Used correctly a plunger will help to dislodge clumps of hair and grease. If the clump of hair has become fixed to the drain cover it may be possible to clear the blockage by hand, either by unscrewing the drain cover, or by trying to hook the hair out. To catch hair before it goes down the drain, invest in a shower screen that rests over the plughole. You can then simply remove the hair that has been caught and dispose of it in the bin.

Slow draining in a shower can often be from too shallow trays. When the shower was installed, the tray may not have been placed high enough. As a result, the gradient that the water drains down isn’t steep enough to allow waste to drain away.

Chemical products are widely available for helping to clear blocked bath and shower drains. However, care should be taken when using them. It’s possible you could damage your drainage pipework if you use them regularly and especially if you’re mixing different products.

Using a mixture of bicarbonate of soda and vinegar is a very effective, traditional method of clearing some blockages. The benefits of this method over modern household chemical products are that it’s more ecological, cheaper and it won’t damage your drainage pipework.

Simply pour a cup of bicarbonate of soda down the drain, then leave it for a minute before pouring a cup of vinegar down after it. Two reactions take place; the first is the creation of carbonic acid and sodium acetate. The second is an effervescent reaction with the carbonic acid decomposing into water and carbon dioxide gas.

The two reactions in the confined space of a drainage pipe helps to break down the limescale and grease causing the blockage. After leaving it for an hour or so boiling water can be poured down the drain to help flush the remaining debris away.

Properties in London are more susceptible to blocked bath and shower drains due to the hard water we have. When soap is used in hard water areas, two insoluble compounds are formed that gradually build up and reduce the flow capacity of the pipe.

When you use soap in a bath it’s easy to see the insoluble calcium and magnesium compounds on the side of a bathtub once the water has drained away. Removing this “soap scum” with a detergent and some scrubbing is relatively easy. However, soap scum is not so easy to clean from the inside of a pipe where it can’t be seen!

It’s worth remembering that using a plunger won’t clear these insoluble compounds or limescale from bath and shower drains.