July 17, 2026 Paul Souliac

What Is Jointing Compound & How to Use It on Patios

Jointing compound fills the gaps between paving slabs on patios, paths and driveways. It locks the slabs in place, stops weeds and resists rain washout far better than old sand-and-cement mixes. Brush-in patio grout is the easiest form for most homes. Ready-to-use patio grout simply gets swept into damp joints and set hard without mixing.

Jointing compounds differ in strength, application and durability, with modern brush-in options providing a reliable alternative to traditional mixes. The best patio grout in the UK offers improved weed resistance and weather protection, while understanding patio grout mistakes and the differences between brush-in and traditional patio grout methods helps achieve a durable finish. Brush-in patio grout remains a popular choice for low-maintenance paving joints.

Choose a quality brush-in jointing compound for your next patio project at GoGlean.

What Jointing Compound Actually Does

Jointing compound is a pre-mixed blend of sand and binders made for outdoor paving. Once brushed into the joints it hardens to create a firm, flexible fill. This holds the paving steady, lets water drain through, and blocks seeds from taking root. Traditional mortar pointing cracks over time and lets weeds through. Modern brush-in jointing compound stay put through frost, rain and foot traffic.

The material suits natural stone, concrete, clay, terracotta and many other slabs. It works best when joints are at least 3 mm to 5 mm wide and 25 mm deep. Narrower gaps need different products. Coverage depends on slab size and joint width, so check the product details before you start.

Types of Patio Jointing Compound

Brush-in jointing compounds arrive ready to use in a sealed tub. You open the bag, wet the paving, pour the mix and sweep it in. They cure by contact with air and suit most residential patios and paths.

Slurry or flowable grouts need mixing with water and get poured or squeegeed into joints. These suit very narrow gaps, especially porcelain. Two-part epoxy systems offer higher strength for driveways but take more effort and cost more.

Brush-in types win for most garden jobs. They need less skill, work in damp conditions and leave a natural look that matches the stone. Professional paving products often include both jointing compounds and primers for full installations.

Why Brush-In Jointing Compound Beats Traditional Pointing

Old sand-and-cement mixes demand careful mixing, kneeling work and dry weather. They often crack within a couple of seasons and allow weeds. Brush-in compounds cut the time and mess. You keep the surface wet, brush the material in, compact it and rinse the excess. The result is weed-resistant, water-permeable joints that handle freeze-thaw cycles.

Many installers and homeowners now prefer this approach because leftover product stores under water for later use. No sealing is needed after curing. Colours match common paving shades so the joints blend rather than stand out.

How to Prepare Your Patio for Jointing Compound

Clear all debris, old sand, weeds and loose material from the joints. A stiff brush or joint scraper works well. Rinse the area and let excess water drain. The base under the paving must allow free drainage so water does not sit in the joints.

Check joint size. Most brush-in products need a minimum width of 3 mm to 5 mm and depth of 25 mm. Deeper is better for strength. Work on a day when temperatures stay above freezing. Light rain is fine for all weather jointing compounds, but heavy downpours can wash material out before it sets.

If you are laying new paving, wait until the mortar bed has cured. For repairs, remove failed joints completely so the new compound bonds to a clean surface. A patio grout repair pack suits smaller touch-up jobs.

Step-by-Step Guide: How to Use Brush-In Jointing Compound

Gather a stiff brush or broom, a soft brush for finishing, a hose with a spray nozzle, gloves and a pointing tool if you want a tooled finish when grouting a patio. No mixing tools are required.

Thoroughly wet the entire paved area. Keep it soaked throughout the job. Water stops the compound sticking to the slab surface and helps it flow into the joints.
Open the vacuum-sealed bag and pour a manageable amount onto the wet paving. Work in small sections of a few square metres at a time.
Sweep the compound diagonally across the joints with a stiff brush. Push it firmly into every gap until the joints are full.
Spray more water over the surface. This flushes the material deeper and starts compaction. Top up any joints that settle.
Compact the joints with a pointing tool or the edge of a trowel if a smoother finish is preferred. Fill again if needed so the compound sits just below the slab surface.
Sweep away excess with a clean soft brush at a diagonal angle. Rinse lightly if residue remains. Do not wash material out of the joints.

Leave the area undisturbed. Walking is usually possible after about 24 hours in dry conditions. Full strength develops over several days depending on temperature and moisture. Cold or wet weather slows the process.

For cold conditions some products allow a dry application method, but wet application remains the standard for best results. Always follow the specific tub instructions.

Common Mistakes That Cause Joint Failure

Here are the patio grout mistakes to avoid:

Skipping the pre-soak leaves dry patches that stain or stop the compound settling.
Working in large areas lets the surface dry mid-job and creates weak spots.
Incomplete filling leaves voids that later crack or let weeds in.
Using the product on joints that are too narrow or too shallow reduces strength.
Leaving residue on the surface can mark some natural stones, though most of it weathers away.

Store unused compound correctly. Tip leftovers back into the tub and cover with at least 50 mm of clean water. Kept submerged it stays usable for months. Once exposed to air it hardens permanently.

Choosing the Right Colour and Product for Your Paving

Natural buff, mid-grey, basalt, pure light grey, pure graphite and pure black cover most UK paving. Match the joint colour to the dominant tone in the stone for a seamless look, or choose contrast for sharper lines. Natural sand colours contain no dyes so they weather consistently.

Select a formula designed for your surface. Natural stone and concrete work with standard brush-in compounds. Porcelain often needs a flowable version. Confirm the product suits pedestrian use only unless a heavy-duty option is specified. GLEAN offers a ready-to-use brush-in jointing compound that meets these needs for patios, paths and block paving. It applies in most weather, needs no specialist tools and requires no post-application sealer.

A slurry primer for porcelain and natural stone improves adhesion when new slabs are laid. After jointing, a water-based patio sealer can add extra protection against stains if desired, though many brush-in compounds need none.

Patio Grout - Brush In Jointing Compound | GLEAN

Description

GLEAN BRUSH-IN JOINTING COMPOUND: GLEAN Brush-In Jointing Compound is a ready-mixed, self-setting grout that simplifies filling joints in patios, driveways, and paths. It creates a strong, durable finish that both DIYers and professional installers can rely on for a clean, long-lasting result with minimal effort.
ALL-WEATHER APPLICATION: This jointing compound can be applied in most weather conditions, including rain, so you don’t have to pause projects waiting for dry days. No sealing is needed after application, giving you a low-maintenance, weather-resistant finish. The process requires no specialist tools, making it simple and efficient for any user.
MULTI SURFACE: Perfect for patios, block paving, driveways, and pathways, this compound bonds well with a variety of materials including natural stone, slate, clay, concrete, terracotta, and paving slabs.
COVERAGE: Joints must be a minimum of 25mm deep (30mm is preferable) for proper performance. This product is not suitable for joints narrower than 3mm.
SETTING TIME: In dry conditions, the initial set takes 24-48 hours, while full curing usually occurs within 3-7 days depending on temperature and moisture levels. The surface can generally be walked on after 24 hours in dry weather. Colder or wetter conditions will extend curing time. Once cured, the compound resists damage from freeze-thaw cycles.
STORAGE: Any leftover compound can be stored by returning it to the tub and covering it with at least 50mm (2 inches) of water. This keeps the product usable for several months while submerged. Once exposed to air, it will set hard and form a professional, durable finish.

Need to work out how much product your project needs?

Our easy GLEAN Patio Grout Calculator gives you a quick estimate so you can order the right amount.

Why GoGlean?

Go Glean Ltd is a trusted UK specialist in high-quality hard surface treatments and cleaners. We focus on delivering reliable, performance-driven products designed for lasting results across your home and garden.

Choose quality brush-in jointing compound for your next patio project at GoGlean.

Maintenance After Jointing

Once cured the joints resist ordinary rain and light cleaning.
Avoid high-pressure washing for the first few weeks.
Sweep regularly to stop organic matter building up.
If weeds appear later they usually indicate incomplete filling rather than product failure.
Spot repairs with a small patio grout repair pack restore the surface quickly.
Residue from application can be removed with a specialist cleaner designed for acrylic or resin films if it does not weather off.
Keep drainage clear so water does not pond on the paving.

When to Call a Professional

Large areas, steep slopes or driveways with vehicle traffic may need specialist compounds or experienced installers. Complex patterns or porcelain with very tight joints also benefit from trade knowledge. For standard garden patios the brush-in method stays within easy reach of most homeowners who follow the steps carefully.

FAQ

What joint size works best with brush-in jointing compound?

Most brush-in jointing compounds perform reliably when the gaps between paving slabs measure at least 3 mm to 5 mm wide and reach a depth of 25 mm or more. Shallower or narrower joints limit how firmly the material can lock in place and may lead to early movement or incomplete filling. Always measure several joints across the patio before starting, as natural stone and concrete slabs can vary slightly. Matching the product to the actual joint dimensions helps create a stable, long-lasting finish that resists washout.

Can I apply jointing compound in the rain?

Many ready-to-use brush-in formulas are designed for all-weather use and can be applied during light rain or on damp surfaces. Heavy rain during the application itself or in the first hours of curing can displace the material before it has a chance to settle properly. Working in smaller sections allows you to keep control and finish each area before conditions worsen. Keeping the paving thoroughly wet throughout the process remains the key step regardless of the weather.

How long before I can walk on the patio?

Light foot traffic is usually possible after around 24 hours when conditions stay dry and mild. Full curing continues over the following days as the compound hardens and gains strength. Cooler temperatures or ongoing damp weather slow the process, so it is sensible to wait longer before placing furniture or allowing heavier use. Avoid disturbing the joints during this period to give the material the best chance to set evenly.

Does jointing compound stop weeds completely?

A fully filled and compacted joint creates a physical barrier that makes it difficult for most seeds to take root and grow. Incomplete filling or later damage to the joints can open pathways for weeds, so thorough preparation and careful application matter. Regular sweeping helps keep organic matter from building up on the surface. Spot repairs with a small amount of matching compound restore any damaged sections and maintain the barrier over time.

Can leftover jointing compound be stored?

Unused product can be returned to its original tub and covered with at least 50 mm of clean water. As long as the material stays fully submerged it remains workable for later use. Once the water is removed and the compound contacts air it begins to set hard, so storage conditions need to stay consistent. This approach reduces waste on larger projects where only part of a tub is required.