Cleaning tile grout - what really works

Planning & prior knowledge

If you want to clean dirty tile grout in your bathroom, shower or outdoors, it’s worthwhile taking a closer look at the situation before you start scrubbing right away. How you proceed depends on the type of grout and the amount of dirt you are dealing with.

Why does grout get dirty?

As far as contamination is concerned, you can be confronted with anything that settles on or penetrates grout, including shampoo residues, grease splashes, rain, leaves or soil. Mortar grout, with its rough surface, is particularly susceptible to all kinds of dirt.

The other big issue is mould, which forms due to too much humidity in a room. Cooking, as well as showering, produces a lot of water vapour that condenses on the tiles and grout joints. Damp and warm environments are always the perfect breeding ground for bacteria and fungi. Without sufficient ventilation, regular grout cleaning is a must.

What are the different types of grout and which agents should be used to clean them?

Mould or dirt residue requires different cleaning agents and methods to remove. But the type of cleaning agent you should use also depends on what the grout is made from. Indoors, you’ll mainly find grout made from cement-based mortar or so-called expansion grout found between walls and the floor, which is almost always made of silicone.

How do you find the right method for cleaning your grout? Above all, the grout in the bathroom and kitchen should be look clean and newly installed again. But you should also be careful not to damage the joints or the tiles by cleaning them.

Speaking of which: Tiles are a big topic with us. We have step-by-step instructions for putting up tiles yourself. You can remove an individual tile or renovate the whole kitchen. 

Back to grout cleaning and an example of different cleaning agents: You should avoid aggressive acids such as vinegar or citric acid for cement grout as they attack the mortar and make the grout porous. This makes it easier for moisture to penetrate, in the worst case scenario right behind the tile.

Finding the right cleaning agent can be a little confusing at first glance. You can find numerous tips and ideas on the internet, but not all of them really help with grout cleaning.

There are bleaching agents, grease- or limescale-dissolving cleaners, agents with and without chemicals, in liquid or powder form. Others rely on mechanical abrasion to clean dirty tile grout. The following diagram will help.

Basically, you should observe the following when cleaning grout:

• Mineral deposits such as limescale and urine scale, and often also rust, can be removed very easily with acids. But: they can attack the grout material and make it leaky. Therefore, caution is advised when using acids for cleaning tile grout. This applies to cleaning cement grout as well as silicone grout.
• With alkalis, the higher their pH value, the more corrosive they are. Lye with soda or bicarbonate of soda is good at dissolving organic soiling such as grease and protein. In our instructions below we use bicarbonate of soda, which belongs to the alkalis.
• Organic solvents are good for anything that is not water soluble. But remember that chlorine can also be harmful to your health and is not good for the environment.
• Abrasives: Especially if you want to clean cement grout, the effect of mechanical abrasion is not to be sneezed at. With a small stainless steel brush, the layer of dirt can often be removed relatively easily. Whether this method is possible in your case depends, of course, on the condition of the grout.

After cleaning dirty tile grout, are you still in a cleaning frenzy? Then take a look at our 5 tips for cleaning windows. We can also help you with doing some proper wood maintenance in spring for the outdoor furniture on your balcony or terrace. Removing moss from outdoor areas such as your driveway or a stone wall can also be done with our practical tips.

An interesting alternative is the so-called oxygen bleach. When used with hot water (50°C or higher), it decomposes into water, soda and active oxygen, or more precisely: hydrogen peroxide. The advantage: oxygen bleach is completely biodegradable. Moreover, unlike pastes, you can easily apply the cleaning agent with a spray bottle.

Bleaching with oxygen has been known for centuries. In the past, people used to lay cloths that were still damp from washing on a lawn for so-called lawn bleaching. The combination of sunlight and the photosynthesis of the lawn formed peroxides and certain oxygens that made the laundry beautifully white. Try using oxygen bleach to clean your dirty tile grout.

Another tip: There are special products that you can spray on or use as grout sticks to seal your grout and protect it from environmental influences. Unlike tile varnish, however, the protective effect wears off over time. You should therefore re-apply these products at regular intervals. This may be more efficient than frequent grout cleaning.

What can I use to clean grout?

Regardless of the cleaning agent you choose, you still need a suitable tool for cleaning grout. There are many tools: from sponges to special grout brushes to electric toothbrushes.

But if you've ever tried cleaning grout in your bathroom or shower with a toothbrush, you know how exhausting it is. So, here's another super hack: Simply clamp a brush into your cordless drill! You can make it yourself from a grout brush, a long screw, washers and a nut. Or even better: you can use a battery-operated cleaning brush.

Costs for cleaning grout

Whether floor, wall or patio tiles: Grout cleaning is not an expensive DIY project. You can usually manage with just a few tools. Of course, it will be more expensive if you hire a professional service provider to clean your tile grout. But even in this case, the effort is limited.

For indoor areas, you can estimate the costs with the hourly rate for a cleaner. With an hourly rate of £10 an hour and an assumed average cleaning time of 20 minutes per metre of grout, three metres of bathroom, shower or floor tile grout cleaning costs £10.

If you want to have tile grout cleaned outdoors, it again depends on what exactly is being cleaned. Mortar grout can be cleaned with a steam cleaner, while patio grout may need to be weeded. There are large regional differences in the prices for this, but you should assume a minimum hourly wage of £17.

Let's go – Cleaning grout step by step

Here is a brief example of how you can clean bathroom grout. We are assuming cement grout joints that are dirty but have at most minimal mould growth. Simply use bicarbonate of soda, which is cheap and effective.