How to stop weeds in block paving

How To Stop Weeds In Block Paving

Learn how to tackle and prevent weeds from growing through block paving. This article will go through the equipment you’ll need and methods for stopping and preventing weeds from giving your garden a messy and ugly look.

The last thing you want is an evergrowing space of weeds coming up and through to your gardens block paving. To get started you’ll need the correct equipment.

Equipment required to tackle the weeds

Throughout the UK, block paving is seen and recognised as one of most the popular choices for gardens and driveways. It’s not too expensive, visually looks good for your garden or driveway, and provides a strong and long-lasting pavement.

The one thing that can give your patio an untidy look is weeds growing through the gaps around the sides. Weeds growing in the garden can be a chore to keep up, which need pulling or digging out once every so often.

Let’s begin with removing the weeds, thoroughly washing and cleaning the patio ready for sanding the gaps, and finally, sealing off your block paving to prevent weeds growing through. 

We’ll also go through alternative methods further down the article.

How to Remove Weeds

Follow these steps for removing weeds efficiently and preventing them from growing back.

Ensure to Wear Protective Gloves

It’s important to protect your skin from the chemicals being used and any irritable plants badly reacting to your skin. Here are a good, cheap pair: Beeswift MULTI-PURPOSE GLOVES BLACK M

Weed Removal – Using Product Chemicals

They’re plenty of different types of weedkiller products for you to use. A concentrated spray bottle weedkiller is right for the job for block paving. It’s a fast way of dealing with the on-growing situation in your garden.

Spray all areas of the patio with your weedkiller. Be sure to spray everywhere in between the gaps, even the areas that don’t have any weeds growing. Don’t worry about the very tiny weeds that are difficult to get out. This will be covered with the next step by using a pressure washer.

We’ve done a long post on the best weed killers for block paving but if you don’t want to read it all, the best weed killer we picked out from those is Weedol Rootkill Plus

Cleaning with a pressure washer

After removing the weeds, it’s important to give your patio an intensive wash without disturbing or damaging your floor or other surfaces. This will prepare the area for the step after.

Pressure Washing

A great way to start washing your patio and clearing up any missed small weeds is using a pressure washer. The small weeds can be difficult to get out, but a pressure washer will do the job getting them up.

This will help get rid of any excess weeds and any additional debris.

One important thing to note before you start – If you hold the pressure washer too close in the gaps of the patio, this will disturb the underneath bedding of the block paving slabs.

The aim will be to ensure the ground is clean and clear as possible, without ruining any structure. Once you have washed your patio, the next step is to leave it to dry. Leave it for 24 hours. 

This is important towards the next step of sanding the gaps and also important for any chemical residue has wiped away from the weedkiller. In order to sand and use sealant effectively, the patio area will need to be bone dry.

Sanding & Using a Sealant for the Gaps

After removing the weeds, thoroughly washing your patio area and pressure washing down all surfaces, it’s time to sand in-between the joints and use patio sealant to ensure no weeds will grow back up through.

Sanding the Gaps
Leading up to the sanding the joint gaps, you will need the surface to be dry throughout. As mentioned above, you will need to leave your patio to dry for 24 hours. 

Getting the best results will come down to good weather with no rain throughout the process. It’s also advised to do this work with 2 or 3 consecutive days of good weather.

The first step to placing in the sand is to quickly go over your patio and thoroughly check of any new weeds growing back. 

Begin by putting down sand between the paving gaps. Use a small handheld brush to assist in pushing it down and brushing it into place.

Be careful of overflowing the bed with sand, so that it’s not higher than the surrounded joints. Sweep away any excess sand in the joints, as this will help evenly spread the sand and will also help towards cleaning up the slabs.

Once you’ve finished placing the sand going over all joint areas of the block paving. The next step is to seal the gaps. This is recommended to carry out on the same day as you sand, as the sand works alongside the joints as soon as possible.

Sealing the Gaps
Once you’ve chosen your patio sealer product and have it at the ready, it’s important to follow these steps carefully as you don’t want to seal any stains or marks. As by doing this, it will make it near impossible to remove after you’ve finished sealing the patio.

Sweep away any leaves, stones, soil, and any dirt or dust on top of your patio slabs, and remove any stains before applying the sealer. Be sure to make it as clean as you can before you start the seal.

Once you’ve cleared as much debris as you can and the patio is cleaned thoroughly. A professional-grade patio cleaner is required.

The first applied coat of sealant is for impregnation and will be the first level applied of patio sealant to your paving slabs. A low-pressure sprayer is most recommended to have an even finish. You can use a sponge, brush or paint pad.

Apply the patio sealer at a ratio of 150 ml per metre squared. If using a low-pressure sprayer, it’s recommended to apply the patio sealant in circular and consistent motions, going slab by slab, whilst paying attention to which parts you have sprayed each time.

Now that you’ve applied the first coat of sealer, the next step is to apply the second coat. The purpose of the second coat is an added surface protection. The process is repeating the first steps you’ve carried out but this time at a 100 ml per metre squared depth.

Finally, let the patio dry for a minimum of 2-3 hours and you have successfully completed the sealant process.

Recommended Actions for Sealing Paving Slabs

  • Wear Protective Clothing – gloves and eyewear. Some paving sealants use a solvent-based product. It’s recommended checking the product label before you use.
  • Carry out a Sealing Test – you can double-check if the sealant is suitable by carrying out a test in a hidden, closed away area. Apply a little patio sealant to the chosen area and let it dry for 2 hours.

    The reason it’s recommended to do this is once the sealant is applied, it can be very difficult to reverse the effects of a patio stone sealer.
  • Protecting Surfaces – It’s recommended to mask surfaces such as wooden decking and plastic.
  • Check the Surrounding Area for Sensitive Surfaces – in case of any spills, over spraying or accidental splashes.
  • Sealants should not be applied to any pavement that is less than 3 months old – This is down to maturing and allowing traces of efflorescence to have completely disappeared.

Types of Sealants

There are 5 main types of block paving sealants.

  • Water-based Emulsions
  • Solvent-based Polyurethane Sealer
  • Solvent-based Acrylics
  • Hydrated Polymer Glues
  • Moisture Cured Urethanes – Also known, Specialist Pre-Polymer Urethanes


The most common sealants are the acrylics and urethanes. Each sealant is targeted at specific paving so it’s important to choose the right one for your patio. Look into the sealant for any additional information and be sure to read the label for suitable use.

The acrylic sealants are typically used on PIC and residential paving.

  • Everbuild is a great water-based paving sealer.
  • Adeseal solvent-based acrylic sealer is a top recommended solvent to use for block paving.
  • Resiblock solvent-based polyurethane sealer is another well-recommended solvent for paving.

More Ways of Removing Weeds 

There are other methods you can use to get rid of weeds growing in your block pavement.

Using Salt
A cheap alternative is using salt in the ground. This is an old tactic used back many years ago and is proven to be an effective way of stopping weeds growing in the ground.

Be sure when using salt that it is only applied to the areas for weeds growing as it can kill everything and prevent growth in the soil.

As rainy weather will wash away salt over time, reapply every 6 months in the ground. Salt is ideal for block paving as it’s the only objective is to tackle weeds growing in-between the gaps. Salt wouldn’t be ideal for larger areas of soil for the chance to grow plants for example.

Weed Burners
Another effective method is to use weed burners for your block paving. It’s like a heat gun that burns away the weeds. It’s also highlighted as an environmentally friendly way of dealing with weeds in your garden.

Using a weed burner is mainly focussed at a more permanent removal of individual weeds, rather than pulling them up yourself. Inspect your garden and burn away the weeds.

As mentioned weed burners are an environmentally friendly way and considered one of the cleanest methods of removal. They’re not guaranteed of completely stopping the weeds growing but is a clean way.

You can either have electric or gas versions of weed burners. It is recommended that gas will have more effective approaches and ultimately, a faster way for results.

Final say

Fighting weeds that are growing in your garden can be a chore as mentioned. Especially when new weeds reappear every so often. As you can see, they’re many ways of dealing with weeds growing in block paving.

They’re cheaper options such as salt, faster ways such as using a weedkiller and hand removing them, environmentally friendly ways using a weed burner, and finally, there’s an expensive approach but most effective through using a sealant. The sealant is the one method to hold the highest prevention of weeds growing.

About Steven

An enthusiast of DIY and household ideas. I've experience my fair share of tough projects in my time and have learnt a lot along the way. I enjoy a good DIY challenge, sharing my experience & research.

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