How to use paving jointing compound

Whether you’re jointing a freshly-laid patio or if you’ve arrived here from our previous section after removing some old patio grout, it’s time to break open your jointing compound. 

Instructions for how to use paving jointing compound will differ slightly depending on the type of compound you have chosen, so always read the directions on your product carefully before you start. But most of the jointing compounds we sell here at Build & Plumb require the same or similar materials and tools, and follow the same processes. 

For the purpose of this how-to, we’ll be showing you the instructions for applying pre-mixed polymeric brush-in jointing compounds – the most popular and easiest to use on the market. 

What you will need:

• Your chosen paving jointing compound 
• A yard brush
• Water and watering can (to pre-wet your paving slabs)
• A jointing tool or brick jointer
• A tape measure or ruler (for measuring the width and depth of your joints)
• Gloves

How to apply the jointing compound:

Step 1: Check your joint width and depth

Most patio jointing compounds require there to be a gap of at least 5 mm between each paving slab, and a depth of at least 15 to 30 mm for the compound to sit in. Check the instructions on your chosen jointing compound to make sure your paving joints are the correct width and depth for your product.

Step 2: Pre-wet your paving

Again, check the instructions of your chosen compound first, but most pre-mixed brush-in compounds do require you to pre-wet your paving. The easiest way to do this is to use a watering can with a sprinkler rose attached, as this gives you a light, even coating of water over a large surface area. Once your paving is evenly wetted, check to make sure there are no areas of water pooling. Use your brush to remove any pooling before you move on to step 3.

Step 3: Apply your compound

Pop your gloves on and open up your compound. Using your hands, start sprinkling an even layer of your paving joint compound onto your paving stones. Do this in smaller sections if you have a particularly large paved area.

Step 4: Brush it in

Once you’ve applied your jointing compound, use your yard brush to start sweeping it into the empty joints between your paving stones. For the best results, sweep it across your joints at a 40° angle. Make sure all the joints are all fully filled with compound as this will prevent premature cracking later down the line.

Step 5: Smooth it in

This is where your jointing tool or brick jointer comes in handy. If you don’t have one, you could use a palette knife or anything with a broad, smooth, slightly curved surface. Simply run your tool along the joints between your paving stones, pressing firmly as you go. This helps pack in your jointing compound and remove any gaps. 

Step 6: Remove any excess

Use your brush to sweep up any excess jointing compound. If there is lots left, sweep it back into its bag or tub, just in case you need to top up later down the line.

Step 7: Leave it to dry

This type of paving jointing compound is designed to self-cure and dry quickly, even if it’s raining outside. Your joints should be fully cured within 72 hours if you have dry weather, but could take a little longer in particularly wet or cold conditions. 

That’s it, you’re all done!Now you know how to use paving jointing compound, you’re ready to start your project. Explore our full range of high-quality jointing compounds here at Build & Plumb, including dry sand and brush-in compounds for a quick, quality finish.