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How To Lay Your Patio

Patio expert Clive says that the drying time varies depending on how your slabs have been laid. Usually 24 hours should do the trick, but if you’re in any doubt, leave it another 24 hours. You don’t want to be ruining all your hard work!

Watch the video to see just how easy pointing really is…

Choosing Your Slabs

Before you start laying your patio you need to plan. You’ll need to plan the dimensions of your patio and decide on the type of patio slabs that you want to use and you can plan how many you need to buy.

What You Will Need

  • Patio flags or slabs
  • Mortar / Cement and San / Slablayer
  • Builders’ square
  • Rubber mallet
  • Spirit level
  • Fast Point
  • Shovel
  • Trowel
  • Pointing Iron
  • Medium-stiff brush
  • Sponge
  • Clean Water
  • Gloves
  • Builders’ bucket

Laying The First Slab

The positioning of your very first paving slab is of paramount importance: if the first slab you lay is in the wrong place, your whole patio will suffer.

Start off with the corner slab that is closest to your house, using the builders’ square to ensure that the string guidelines are square to the building. If not, re-align the strings so that they are accurate.

Check the consistency of your mortar before laying. Wearing suitable gloves, scoop up a ball of the mortar in your hands and shape into a firm ball. When you take your hands away, the ball should remain in the same shape without falling apart, and without leaking water. Adjust if necessary.

For a larger area you can alternatively mix your own sand and cement or use Blue Circle Slablayer.

In your starting corner, trowel enough mortar onto the foundation for the first paving slab: aim for a mortar bed that is around 40mm deep. Level the mortar off with your trowel, but do not compact it: you want the paving slab to sit at a depth of around 10-15mm.

It’s now time to lay the first slab. Pick up your slab (carefully, as it may be heavy) and lay it in place, being careful not to slide it around in order that you create a good bond between the mortar and the slab. Ensure that it is lined up with your strings, then use your rubber mallet to tap it carefully into place.

Laying The Remaining Slabs

Lay the remaining paving slabs in the same way as the first: again, ensuring that you follow the string guidelines that you previously set up. Using your spirit level, check that each slab is level, and be sure to leave consistent gaps between each slab (generally between 10 and 15mm). A simple and cheap but effective way of ensuring the gaps are consistent is to buy a piece of 10mm dowel and break it up to make spacers. Once finished, carry out a final check to make sure your patio is level.

Whether using one of our patio paving packs or crafting your own design from individual tiles, this method will work across the board.


When all of your slabs have been laid, leave them to settle for at least 24 hours. This will ensure that the mortar dries and creates a bond with the slabs: a lack of bond could cause movement, and could allow weeds to grow through the gaps. In wet or cold weather, it is wise to cover your patio with a polythene sheet whilst drying.

Once dry, it’s time for pointing: filling in the gaps that you have left between each slab. For ease use Fast Point Jointing Compound or if you are a traditionalists use a combination of four parts building sand to one part cement, adding just enough water to create a semi-dry mixture that you should be able to ball in your hand without it crumbling or seeping water.

Using a trowel, press the mortar into the gaps to ensure they are well-filled. Before it has time to dry, clean off any residue from the tops of your slabs with a medium-stiff brush, then use a sponge soaked in clean water to finish the cleaning process.

Again, your newly-pointed patio should be left for an additional 24 hours for the mortar to set. Then, you can get the barbecue out and host your first patio party.

Tips From The Expert

How Many Bags Or Tubs Of Blue Circle Mortar Will I Need?
You can calculate the amount of Postcrete you will need by using this handy online calculator.

Where Can I Find More Information About Mortar?
For more information about the Mortar product itself, take a look at this detailed product data sheet.

Where Can I Find More Information Regarding Health & Safety When Using Mortar?
Before using this product, please refer to the product packaging for all health and safety information. You can also take a look at this detailed material safety data download.

Can I Recycle The Packaging?
Yes, all Blue Circle plastic packaging is made of recyclable material so is suitable for recycling and should be disposed of in the correct manner.

We hope you found this guide useful in learning how to mix mortar ready for your building projects. Hopefully you are now feeling confident enough to complete your project to a professional finish. For a video breakdown of the process, you can head to this step-by-step video demonstration.

If you found this post useful, please tag us in any social media posts of your projects using @BradfordsBuild on Facebook, @bradfords_building_supplies on Instagram, or bradfords-building-supplies-ltd on LinkedIn, so that we can see the finished result.

If you need further help or advice, please contact us or visit your local branch to speak to one of our experts.