Sealing pavers helps prevent weed growth between your pavers and patio stones. Sealant seeps down into the joint sand between your pavers and hardens it to mortar-like consistency, which stops weeds from taking root in your paver patio.
Sealing your pavers and patio stones provides several benefits, including:
- Prevents weed growth.
- Stops mold, algae, and moss from forming on pavers.
- Keeps pavers from cracking (cracked pavers invite more weeds).
However, sealing your pavers is a multi-step job. If your main goal is to stop weeds from growing between your pavers, you may opt instead to use polymeric joint sand between your pavers and stop there. This joint stabilizer hardens when you add water, and doesn’t require the use of sealant. When you use polymeric sand in the seams between pavers, you will put a stop to those weeds without sealing your pavers.
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7 Steps to Seal Pavers to Prevent Weed Growth
First things first, weeds currently growing up through the seams between your pavers must go. There are a few ways you can kill these weeds.
- Use a flathead screwdriver or knife to dig weeds out from the cracks.
- Spray weeds with a commercial weed killer, such as RoundUp.
- Spray weeds with a natural weed killer made by mixing a bottle of vinegar with a quarter-teaspoon of dish soap.
Clean Your Pavers
It’s important to start with a clean slate when sealing pavers. Any dirt, grime, or mold present on the pavers will be trapped under the sealant if it’s not removed first.
Use a hose or pressure washer to thoroughly clean all the pavers you intend to seal. A pressure washer will help eliminate any unwanted grime and dirt. Once you are happy with the look of your pavers, allow them to dry before proceeding.
Add Joint Sand Between Pavers
Apply either polymeric sand or standard joint sand between the pavers. You can do this by simply pouring the joint sand into the seams with a cup or funnel.
Sweep excess polymeric sand into the seams between the pavers. Joint sand should be ⅛ inch below the level of the pavers. Add or remove joint sand as necessary to achieve this height. Then, using a rubber mallet or tamper, tap the pavers. This will help settle the joint sand into the cracks, creating a more compact and weed-resistant final product.
Remove Excess Joint Sand
Even the most careful craftsman will end up with some excess joint sand on the pavers after filling cracks. Any joint sand left on top of the pavers during sealing will be trapped there, creating a dirty, ugly look. Additionally, if you’re using water-activated joint sand (such as polymeric joint sand) any joint sand left on top of the pavers during the next step will harden like mortar and fuse to your pavers.
Use a broom or leaf blower to blow away any joint sand on top of the pavers. Be careful not to remove the joint sand you’ve just installed in the seams.
Add Water to Joints
Using a sprayer, mist the seams between the pavers. Refrain from using a hose or high-powered spray nozzle, as this can disturb the joint sand and ruin your hard work. Repeat this misting 3–4 times in a 1-hour period. This will ensure proper water infiltration.
In cases where you’ve used polymeric joint sand, the water will activate the joint sand, causing it to harden. If you’ve used conventional joint sand, the water will help compact and harden the sand. After applying water, allow the pavers to dry.
Follow the directions on your sealant of choice and apply it to your pavers. It’s a good idea to test a small area first, to make sure the sealant doesn’t discolor your pavers.
Many sealants are applied by sprayer, making it a quick job. Make sure to apply the sealant evenly to all pavers and seams. There’s no need to soak the pavers or joints. Apply a thin layer and allow it to dry for 2–3 hours, then apply a second coat.
Once the sealant has dried for 2-3 hours after the final coat, the paved surface should be safe for use.
Is it Necessary to Seal Pavers to Prevent Weeds?
It’s not necessary to seal pavers to prevent weeds. Weeds in pavers crop up when weed seeds enter the cracks between pavers and sprout up there. To stop this, what you need to do is fill the cracks between the pavers properly.
You can use water-activated polymeric joint sand to mortar the seams between your pavers without sealing. This will stop weeds without the need to go through the additional steps of sealing the pavers.
Some types of joint sand are designed to be used with sealant. These products soak up sealant in order to harden and resist weeds. If you’re using one of these products, you will need to seal your pavers to stop weeds.
Keep in mind, sealing your pavers protects them from weather and moisture, preventing mold, mildew, algae, and moss, as well as keeping your pavers from weathering and cracking. While sealing your pavers isn’t necessary to keep weeds out, it is great for the overall look and maintenance of your pavers.
How Often Should Pavers Be Sealed for Weed Prevention?
Pavers should be re-sealed every 3–5 years for optimal protection. If you use an acrylic sealer, or your outdoor space is subjected to heavy traffic and/or extreme weather, consider re-sealing every 2–3 years.
When re-sealing, follow the same steps that you would in the initial sealing process. This is the best way to maintain your pavers and make sure weeds don’t invade.
5 Easy Ways to Prevent Weeds From Growing Between Pavers and Patio Stones
If you don’t want to invest the time and money in resealing or adding joint sand to your pavers right away, there are other DIY methods to keep weeds from growing between your pavers. Here are the best methods:
Commercial weed killers such as RoundUp do a great job of killing weeds permanently growing between pavers. They contain active ingredients that kill grass and weeds down to the root. Some varieties are even formulated for long-term weed control and prevent weeds from coming back for up to a year.
- Kills the toughest invasive grass and weeds down to the root.
- No-mix formula that is convenient and easy to use.
- Rainproof in 10 minutes with visible results within 3 hours.
A homemade weed killer made from white vinegar and a quarter-teaspoon of dish soap in a spray bottle will kill weed leaves coming up through pavers. Vinegar destroys the leaf cuticle, killing the plant. The dish soap adds viscosity, which helps the white vinegar cling to leaves and do its work.
One thing to consider with vinegar is it does not kill weed roots, so it isn’t a great long-term solution.
A kettle of boiling water is one of the simplest weed-killing devices there is. Simply pour boiling water on the unwanted plants coming up through your pavers. A few applications should kill them, but similar to vinegar, the roots will most likely remain.
Salt makes soil poisonous to plants, preventing the growth of weeds and grasses. You can add salt to your vinegar-and-soap spray, or simply dissolve salt in your boiling water to boost its effectiveness. Be careful, however, as salt runoff from the patio will affect lawn grass or garden plants, it will kill them and prevent regrowth in the salty soil.
Propane-fueled flame weeders are a natural way to kill weeds and destroy weed seeds on the plant. They’re perfect for use among pavers because there is little chance of the flames spreading to any desirable plants.
Can Sealing Pavers Prevent Weeds?
Sealing your pavers and patio stones is a terrific option for protecting your outdoor space, with a number of benefits. That said, pressure washing then filling the seams between the pavers with joint sand is what really puts a stop to those weeds.
While some types of joint sand require a sealant to harden and form a weed-proof barrier, you can get specialized joint sands (look for polymeric joint sand) that harden on contact with water. You can use these joint sands alone to get rid of the weed problem in your pavers, or combine it with a sealant to protect your pavers from weeds, mold, moss, cracking, and weathering all at once.