Weeds pushing up through paver joints are a common nuisance that compromises the aesthetic appeal and structural integrity of an outdoor hardscape. A long-term solution demands a comprehensive, multi-step approach. This strategy involves establishing a robust structural defense in the joints, actively eliminating existing growth, and applying a final, protective barrier to prevent future germination. By focusing on both immediate removal and long-term prevention, homeowners can maintain a stable and consistently weed-free patio or walkway.
Structural Defense: Choosing and Maintaining Joint Fillers
The first line of defense against paver weeds lies in the material used to fill the spaces between the stones. Standard loose sand is highly susceptible to washout and offers a fertile, uncompacted bed where airborne weed seeds can easily settle and germinate. This material must be replaced with a specialized product designed to create a solid, impenetrable barrier.
Polymeric sand is the preferred choice, as it is a fine mixture of sand particles combined with polymer binders. Once swept into the joints and activated by a light misting of water, these binders cure and harden the sand into a semi-rigid mass. This hardened joint material effectively locks the pavers into place, prevents the erosion of the base material, and physically blocks weed roots from penetrating the surface.
For this system to work correctly, the joints must be cleaned out to a consistent depth, typically at least two inches, to allow for sufficient compaction of the new material. Insufficient depth or poor compaction will result in a weak bond that cracks easily, creating new entry points for water and seeds. Homeowners should regularly inspect the joints for signs of erosion, such as material loss from heavy rain or pressure washing, and re-sand as necessary to maintain the integrity of the hardened joint.
Active Removal Techniques for Existing Growth
Before implementing any preventative measures, all existing weeds must be completely eliminated, including their root systems, which can push pavers apart over time. Manual removal using specialized joint-cleaning tools or a stiff wire brush is effective for shallow-rooted weeds, but it is often easiest to pull them after a heavy rain when the soil is moist. The goal is to extract the entire taproot to prevent regrowth.
For a non-chemical approach, thermal methods offer quick eradication by scalding the plant’s cellular structure. Pouring boiling water directly onto the weeds will kill the foliage and often destroy the roots in the process. Another popular method is using a propane weed torch, which requires careful application to avoid damaging the pavers themselves or igniting nearby materials.
DIY liquid treatments, such as a solution of white vinegar, salt, and dish soap, are also used to kill weeds. The acetic acid in the vinegar desiccates the plant tissue, while the salt further dehydrates the roots. Homeowners must be cautious, however, as the salt can be detrimental to surrounding lawn and garden plants, and the acid can potentially etch or discolor certain paver stone finishes. Commercially available post-emergent herbicides offer another option, but they should be applied precisely to the joint and according to label instructions.
The Barrier Method: Applying Paver Sealants
Once the joints are cleaned and properly filled with new, cured polymeric sand, the final step involves applying a liquid paver sealant to create a durable, moisture-resistant barrier. The sealant permeates the surface of the pavers and the joint material. The application serves to further stabilize the polymeric sand, creating a stronger bond that resists abrasion and washout.
The sealant creates a hydrophobic surface that limits the ability of airborne seeds to find a moist environment for germination. It also helps block the penetration of organic debris, such as dirt and leaf litter, which can break down and provide a nutrient source for weed growth. Paver sealants typically come in two main types: film-forming, which leaves a visible layer and often enhances color, and penetrating, which soaks in and leaves a more natural look.
Timing is important, as the sealant must only be applied to a completely clean and dry surface, typically 24 hours after the polymeric sand has cured. Depending on the product and the level of foot traffic, the sealant’s effectiveness will diminish over time due to weather and wear. A maintenance schedule of reapplication every two to three years is generally recommended to ensure the protective barrier remains intact.