Grouting Outdoor Tiles: How To Grout Patios, Porcelain & Paving Slabs

Stylish, durable and endlessly practical, outdoor tiles and paving slabs provide the perfect fix if you’re looking to give your patio area a fresh new look in time for summer. 

But, as with any DIY job, the longevity and finish of your project are dependent on using the right materials and installation techniques for the job at hand. And when it comes to fitting outdoor tiles on your patio, outdoor grouting is a must. 

Luckily for you, we’re here to help – giving you practical tips on grouting patio tiles correctly for a fabulous finish. So let’s get started. 

Why you need to use grout

Before we get into the ins and outs of grouting outdoor tiles, let us explain why it’s so important.

Whether you’ve laid your outdoor slabs onto concrete, wooden decking or existing paving slabs, they need to be fully protected from the elements.

This is where your grout comes in. Sealing the gap between each tile joint, grout stops dirt and moisture from getting into the adhesive and behind the tile, which can cause damage and cracks long term. 

This is particularly important when grouting external tiles, as your outdoor tiles will be exposed to the elements, be that heavy summer storms or cold, snowy days. 

Outdoor grouting checklist

Grouting outdoor porcelain tiles is often a job best left to professional tilers. But if you fancy giving it a go yourself, you’ll need a few tiling essentials before you start to get the job done properly.

Here’s a handy list of tiling essentials you’ll need when grouting patio tiles:

1. Outdoor tile grout
2. Flat scraper for mixing
3. Rubber grout float
4. Mixing bucket
5. Clean sponge and cloths
6. Mop and bucket

Grouting a patio with porcelain paving slabs

With your tiling equipment in check, now it’s time to run you through the steps for successfully grouting your patio tiles. 

The steps below are designed to give you the best grouting method for outdoor porcelain paving slabs that have been fixed down with adhesive or a mortar bond. However, the same method can be used with natural stone slabs and ceramic options. 

1. Clean the tiles. Sweep the area and remove all the excess adhesive from the tiles using a damp sponge or microfibre cloth to scrub stubborn patches. Allow the area to fully dry

2. Mix your grout. Following the manufacturer’s instructions, use a mixing bucket and flat scraper to blend together the grout powder with clean, cold water. Mix it thoroughly until you get a completely smooth consistency

3. Apply the grout. Working in sections, pour a small amount of grout onto your tile joints, then use the rubber grout float to press it down into the tile joints. Running the grout float diagonally over the joints and changing directions will help ensure it fills every small hole for a complete seal

4. Wipe away excess grout. Before the grout sets in place, use the edge of your grout float to scrape off the excess grout around the joints. Then clean the entire area with clean water and a damp sponge. Run the sponge gently over the grout joints for a smooth finish, being careful not to pull the grout out

5. Leave to dry. Drying times vary depending, so check the tile grout manufacturer’s guidelines. Once your grout has fully set, run over the area with clean water and a mop to remove the cloudy grout residue – this may need to be done several times

So there you have, five simple steps for grouting external tiles for your patio. 

There are different ways you can grout patios with paving slabs. However, the above method is one of the best patio grout processes that can be applied to install various types of outdoor paving slabs. 

Regrouting a patio

In some instances, your patio may not need to be fully re-tiled. More often than not, the grout shows signs of ageing long before the robust outdoor tiles do. 

In these scenarios, a simple regrout of the joints can give it a new lease without having to start from scratch – saving you time, money and wasted materials. 

When regrouting patio tiles, you can follow the steps above when it comes to actually applying the grout. You’ll need to do a little groundwork beforehand to get to that point. 

1. Remove old grout. New grout won’t bond with the existing grout, so you’ll need to remove it from the joints. The quickest way to do this is to use an angle grinder to cut out the old grout  – be careful not to cut into the edges of the tile

2. Clean the tile joints. Using a special grout removal tool or screwdriver, scrape out the large pieces of grout in the gaps between the tiles. Use a brush to sweep out any remaining dirt and debris within the joints and sweep the whole area ready for grouting

By following these preparation steps, all that’s left to do is apply your grout as above and your tiled patio will feel like a brand-new space in no time. 

Choosing your grout colour 

Before we leave you to crack on with grouting outdoor tiles for your patio, we wanted to share a few tips on choosing the right outdoor grout for your patio paving slabs. 

Most modern grouts are designed for internal and external use, which gives you far more choice when it comes to grout colours. From dark grey, black and chocolate brown to beige, vanilla and even blue and green, there are so many options to choose from.

Obviously, much of your grout colour decisions will be based on your tile colour. 

For a classic look, you may prefer to keep your grout colour a close match to your tiles. This can lend a clean, seamless finish that works to make patio spaces feel bigger – perfect for modest-sized gardens.

However, you don’t always have to opt for a shade that blends in with the surroundings. 

Instead, why not make a bold statement with a grout tone that contrasts with the tile? Whether it’s black grout against beige paving slabs or a pale grey to elevate dark slate outdoor tiles, playing with colour contrasts can be an effective and fun way to add personality to your patio. 

Whether you’re grouting new external tiles or regrouting a patio, following the above steps will ensure you end up with a professional finish with your patio grouting project. 

If new tiles are on the agenda, check out our complete range of durable outdoor patio tiles right here. And if you want more ‘how to’ tips and styling inspiration for outside and inside your home, our interior design blog is the place to go.