Happy Drains Blog

Chemical Drain Cleaners: Do They Work?

If you have tried unblocking a pipe with no success, you might be tempted to use a chemical cleaner to remove the blockage. Before you do, we would advise finding out more about what these cleaners are, and whether they are effective.

Chemical Drain Cleaners: What Are They?

Chemical drain cleaners are designed to unblock pipes and are available in either solid form (powder or flakes) or liquid form. Although most are available to buy from most DIY shops, some of the very strong, acid based products are only meant to be used by licenced professionals, and are therefore harder to find.

Alkaline Drain Cleaners

     • Alkaline drain cleaners are the type mostly found in DIY shops, available for anyone to buy and use at home.
     • Products containing sodium hydroxide (also known as lye or caustic soda) are intended to dissolve light substances such as grease, soap and hair. The          chemicals create heat to soften the blockage, and because the product is heavier than water, it will easily travel through water.
     • Some alkaline drain cleaners come in a two-part solution – these are mixed together as they are poured into the drain. As the solutions react, they create        a foam inside the pipe that is intended to dislodge the blockage.

Acid Drain Cleaners

     • Generally, acid drain cleaners are sold in liquid form.
     • Acid cleaners are not widely available in DIY shops because they can be incredibly dangerous. This is why they are usually only available to licenced              plumbers.
     • These products tend to contain a large volume of sulphuric acid, which reacts with the blockage, causing heat and gas that should remove the clog.

Chemical Drain Cleaners: Do They Work?

The advantage of chemical drain cleaners is that they are readily available. If you encounter a blockage at home, you can just pop out to the shops and pick up a bottle. They are also fairly easy to use and can be effective for removing small blockages such as hair and grease.

However, there are many instances in which a chemical drain cleaner will not be effective. For example, if the cleaner does not make direct contact with the blockage (e.g. one that is downstream of a WC or further down the drain), it will not work very well. Also, chemicals simply lack the ability to get rid of most solid obstructions.


When using chemical drain cleaners, extreme care should be taken. It can be easy to ignore the instructions on the bottle, but do not underestimate the power of these cleaners; they are extremely toxic and could seriously damage the person using it if accidently spilt or ingested. They will also damage wood, paint, aluminium and fiberglass. For this reason, chemical cleaners must always be used in accordance with the manufacturer’s instructions.


In our opinion, chemical clearance products are usually best avoided. If you are worried about a clogged drain, give us professionals a call. We can effectively diagnose the problem and work out the best solution for you.