Regrouting tiles: How to remove old and add new grout

Person applying grout to white tile with a grout float
(Image credit: Getty Images)

Regrouting tiles is a job that most DIYers can tackle. Even if you don’t have much experience in this area, it's a great place to start. You can mix up small batches of grout and practice in a small out of the way area to hone your technique.

More experienced DIYers can jump straight in, but still need to know the essential techniques. If you know how to tile a wall you’ll need to know how to grout. Regrouting is the same as grouting except you need to remove the old grout before you can get started.

Here we tell how much grout you’ll need and the tools and technique to remove the old and add the new for a pro looking finish.   

Regrouting tiles: How much grout will I need?

Before you start regrouting you need to estimate how much grout you're going to need. As a general guideline, a 5kg bag of grout will cover around 10-15m2. This will depend on the size of the tiles, what size spacers are used and how intricate the job could be i.e tiling around a window

Make sure to buy around 10% more when calculating how much grout you need. 

This is especially important when buying coloured grout. Two batches may vary slightly in colour so buy a bigger bag. It’s better to have too much grout than not enough. If you have to buy two smaller bags mix together before making up the grout for a consistent colour. 

Regrouting Tiles: A Step-By-Step Guide 

Before regrouting tiles, you'll need to following tools:

  • Grout removal tool
  • Grout float
  • Bag of grout
  • Bucket
  • Sponge

This is a two-step process that involves removing the old and adding the new.

1. Prepare the area
Removing grout can be a messy job so you need to put down dust sheets to protect surrounding areas and catch falling grout. If regrouting a floor, remove all furniture and obstacles so you have a clear area to work in. Keep a dustpan and brush and bucket to hand to sweep up as you go along. 

2. Remove grout
Get your grout removal tool and start in one corner, work in one metre square sections. Hold the tool and use your other hand to steady the tool-holding hand. Apply pressure and drag the removal tool along the grout line. Repeat until you have removed the grout and move onto the next section.

Alternatively, you can use an electric grout removal tool. This makes the process less labour intensive, but you will have to pay more for the tool.

3. Add new grout
Mix up your grout as instructed by the manufacturer's instructions and only make a batch for around 3-4m2 to stop the grout drying out.  Start in the top corner of the area and add a small amount to your grout float. Push the grout into the gaps with a diagonal motion and go back over the area to make sure that the grout has covered all areas.

4. Wash down and finish
Remove as much grout as possible off the tiles and get a damp sponge and wipe down the area you have just grouted. Wring out the sponge and repeat. Now run a grout finishing tool along the grout to get a smooth even finish. Alternatively use the end of a round pencil. 

Dampen the sponge and keep wiping the wall until the excess grout is gone. Leave to dry. When the grout is dry buff clean the tiles with a clean cloth. 

Do I have to remove all old grout before regrouting? 

Yes and No. If the old grout is mouldy, cracked and discoloured you can invest in the best grout cleaner to see what the grout looks like after cleaning. If a clean makes little difference it makes sense to remove as much grout as possible. The more you remove the better the surface for the new grout will be, meaning it will adhere better and last longer.

You might want a simple refresh or you are looking to change the colour of the grout and the current grout is in decent condition you don’t need to remove all of it. Just make sure that you remove at least 2mm so that the new grout can cover the old.   

How often should grout be replaced? 

This will depend on where the grout is located. High traffic areas like hallway floors, those lovely new kitchen wall tile ideas you have put into action or areas that are constantly in contact with water like showers typically need replacing sooner than out of the way areas.

On average grout should last at least five years if looked after properly i.e. cleaned and resealed (where necessary). But it's more a judgement call on the state of the grout that will decide when it should be replaced. 

If it's going mouldy you should clean and if still in poor condition replace. It it's cracked, falling out or discoloured, it's time to replace the grout.   

How much does it cost to regrout tiles? 

Regrouting is a job any competent DIYer can take on, saving on labour costs. If you are tiling a kitchen splashback or refreshing a bathroom all that needs to be paid for is the grout and a few tools. A 5kg bag of grout along with a grout removal tool and a grout float will have minimal costs — expect to pay around £20-£30.

If you are looking to call in a professional expect to pay around £15/m2. Most grouting jobs should take half a day to one day. Typical daily rates are £150-£200. 

Steve Jenkins

Steve is Homebuilding & Renovating's DIY content editor, and has been a writer and editor for two decades. He is an avid DIYer with over 20 years of experience in transforming and renovating homes. He specialises in painting and decorating, but has strong all-round building skills, having previously worked in the industry for 10 years.