Where to Place Weed Blocks for Pavers

Under the Pavers

• If you choose to use a geotextile to block weeds, it should be installed below the pavers' sand bed and above the gravel base or soil, according to a Gavin Historical Bricks website article. Geotextile is also commonly known as landscaping fabric and weed-blocking fabric. It ensures weeds don't root in the gravel or soil, but it can't stop weeds from colonizing in the sand. The fabric, however, helps stop sand from settling into gaps and openings below the sand layer.

In the Gaps

• Polymeric sand is applied in the gaps between pavers to prevent weed growth. The product includes traditional paving sand blended with polymers that bind the sand particles. The resulting tight fit keeps weed seeds from germinating and extending their roots into paver gaps. In most cases, polymeric sand, instead of paving sand, is packed tightly between the pavers. Applying a thin layer of polymeric sand over existing sand between pavers isn't sufficient to stop weeds, according to GroundTradesXChange.com.

Over the Walkway

• If you have a weed-infested paver walkway or patio that needs help, then sealing the sand between pavers with joint-stabilizing sealer is the only option that doesn't involve pulling up the pavers. Applying the sealer just on the sand between pavers, however, isn't sufficient because a bond over the entire walkway or patio is necessary for the product to work properly. Applying a layer of the sealer provides an invisible barrier against weeds, but it doesn't work on plants already established in the sand. Removal of all unwanted vegetative growth is still required before the sealer is used.

Other Options

• If none of the previously mentioned options appeal to you, consider using a living weed block instead. Planting tough ground-covers in the gaps between your pavers will keep unwanted plants from settling in the gaps. Various mosses and ferns can colonize in the gaps on their own. A little selective weeding by hand can remove the gaps' plants considered unattractive and allow attractive plants to thrive and cover empty gaps. After the ground-covers are established, little to no need for continued weeding remains.