Why does my drain smell? The number one cause of smelly drains

Why does my drain smell? Nobody likes those unpleasant odours that can emanate from shower and floor drains, but have you ever wondered what the leading causes of smelly drains and drain odours are? The most common answer to this very common problem is the build-up of bacteria in the drain trap. These bacteria release smells and methane gas as a by-product of their life cycle. 

Why does bacteria love to live in drains?

Drains provide bacteria and mould a very cosy environment to live in. They are moist, dark and have access to fresh air from above and in a lot of cases readily replenished sources of nutrients including skin flakes, soap, shampoo and other bodily fluids. The result is akin to a Petri dish in science class; you have a stable, nutrient rich environment, perfect for all sorts of nasties to thrive in.

Are odours all I need to worry about?

While bad smells emanating from your drain aren't very pleasant, they also aren't necessarily the only things you need to worry about. Insects (think mosquitoes and drain flies) and pathogenic bacteria can thrive in drains. In the cases of holiday rentals, hospitals, retirement homes or public amenities, unhygienic drains can be more than just be a deal-breaker, they can be detrimental to the occupant's health and wellbeing.

Even a beautiful, modern bathroom can be an unpleasant environment if there is a bad drain odour

Even a beautiful, modern bathroom can be an unpleasant environment if there is a bad drain odour 

Are there other causes of smelly drains?

Yes there are. In our two-part Grate Tips blog series, Causes of Smelly Drains, we take a look at these other causes including blockages, venting and poorly constructed drains.

What can I do about smelly and unhygienic drains?

There are quite a number of ways to keep properly constructed drains from being a smelly, embarrassing nuisance. Some cleaning methods will involve chemical treatments available from your local supermarket and others will take a more natural approach.

Our solution to get rid of smells coming from showers and floor drains is to install a Grate Seal. Yes, we are here to sell our product but we strongly believe people need to make informed choices which is why we will be looking at alternatives in the future as well.

How do bad smells impact your property?

Humans have a very good memory for smells and the sense of smell is closely linked to our emotional perception and memory recall. If you are trying to sell or lease a property, the way it smells can have a massive impact on prospective buyers/renters. Likewise, if you run a business, from a café to a hospital, a bad smell can be a deal breaker and not just discourage repeat custom.

Everyone has had a conversation about “the guy with bad breath”, “that part of the city stinks”, "did that place smell funny?" and will be able to recall it years later. Don’t let your house or business be linked in peoples' minds with bad, odour-related memories.

What is Grate Seal?

To put it as simple as possible, Grate Seal is a durable one-way rubber valve that you install directly into the opening of your shower and floor drains. It lets waste water through but prevents gases and insects coming back. It is the simple and maintenance free way to get rid of odours and improve the hygiene of your shower and floor drains, check out our wide range. Grate Seal isn’t just for the home or your investment property, but is perfect for hospitals, retirement homes, restaurants and other commercial properties. Grate Seal was invented by the highly experienced plumbing team, Tony and Ronnie, and is made in Australia. You can read the story of how the Grate Seal was invented here.

To view our range of Grate Seal products click here. If you have any questions you can contact us through the website or via our Facebook page. If you have enjoyed this blog and would like more great tips, tricks and trends, you can find our Grate Tips blog section here.


  • Hi Scott,
    The Grate Seal is engineered to remain in place within the riser pipe via a frictional fit, with the outward pressure forcing the Grate Seal up against the internal wall of the pipe. The Grate Seal opens to allow the passage of water and debris – hair or other debris which can pass through the floor or shower grate will pass through the Grate Seal with the flow of water into the sewage system. Prices are shown on our website – currently the GS01 model (100mm/80mm) is A$50 + GST. Should you require further information, please don’t hesitate to get in touch at sales@grateseal.com.au.

    Grate Seal Admin
  • Can you please tell me the price of the GrateSeal and what is stopping it from eventually slipping into the pipe and blocking it ?


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