What can I use to fill in the cracks between our concrete tiles on our patio to permamently…?

…stop the weed growth?
We use weed kill and bleach constantly. I think there should be a filler (Putty-like substance) that I could put there to stop the weeds once and for all. Help!!!

6 Comments on “What can I use to fill in the cracks between our concrete tiles on our patio to permamently…?

  1. you do not say what weed kill products you use, nor how close you have plantings to your patio, because that will have an affect on what you can use. there are options, some easier than others.

    If it’s not already there, you can take up the patio and lay out weed barrier cloth underneath it. if you really want to be hard-core about it, you can lay the pavers back in mortar, minimising any chance for the weeds to get a toehold in the filler sand that is normally used between the pavers.

    If there are spaces between your pavers, and not just cracks, then you could try grouting them, but it is liely the grout would start cracking within a season and you’d be back to the beginning. if it is available in your area, you might try applying Vulkem sealant between the pavers. again, there needs to be space enough between them to get the sealant in between. It may very well look funny, though, unless you space it down far enough for some sand on top of it, and then your patio won’t drain between the pavers.

    If there are not plantings in or on the ground around your patio, you can try yearly applications of Monobor Chlorate. Be careful, because this is a general herbicide, and can leach through ground water, killing any plant that takes it in. There are also pre-emergent herbicides, that have a residual effect, as wel, but won’t harm established plantings. (they somehow manage to kill off the plants that are trying to break through the surface of the soil.

    Remember the old adage, you can tell the difference between a plant and a weed by pulling it out. if it grows back, it is a weed.

  2. Most patio tiles are laid on flat ground and held together with mortar or cement on the bottom and in between the tiles. If yours are just laid on the ground loose, you will have the plant growth problem you mention. Your best bet is to remove the tiles and set them in mortar, but this is a lot of work. You could try mixing up mortar and squeezing it into the spaces between the tiles using what looks like a cake frosting funnel. But after awhile, expansion and ground movement will cause the tiles to move apart if they’re not set in mortar at the bottom.

    There are better products to use besides weed killer and bleach. There are special chemicals that will prevent the growth of anything, not just weeds. It lasts for months. I will try to include some links below.

    I hope this helps.

  3. I use a Preen-type product (granulated pre-emergent weed killer). I’d sprinkle it on and sweep it over the sidewalk with a pushbroom. This worked well. You should be able to get it at any garden center or home improvement store.

    If you want a more permanent solution, our neighbors swept dry Redi-Mix concrete mixture over their cobblestone walk. Then they sprayed it with water. It seems to have set and they never have weeds.

  4. if your talking about a gap of more than 1/4 then I would fill them in with mortar (the concrete product used in brick laying). there are dye’s available to mix it if plain concrete color does not appeal to you. there are also pastry bags for concrete to help you get it in place. just like decorating a cake!

    if the cracks or gaps are smaller than 1/4 there are concrete caulks available. a good idea in general to keep moisture out and avoid freeze damage or other water damage.

    both of these are available at any home repair / big box type stores that carry concrete products.

    If there is an issue with movement between the pieces then a latex caulk would be your best bet because it will move with the tiles.

  5. There is no permanent method. I have, at last, realized that something is going to grow in the cracks. I can either enjoy fighting it, or I can get with the program. I never enjoyed fighting weeds, so I have become with the program. Here it is:

    1. Clean out the cracks.
    2. Fill the cracks with sand.
    3. Plant a fine, tough, self-propagating ground cover in the cracks.

    My favorite is creeping thyme. When you step on it a delightful fragrance emanates. Here’s 1 of many places to get this


    If you aren’t there yet, the following lasts many years, but I do not think it looks right.

    1. Clean out the cracks.
    2. Pack any wide cracks with closed cell foam caulking bead, available in several diameters (to match the crack width). It is gray in color and available at every home center in the weatherization area. Leave sufficient space above this bead for the next step.
    3. Insert elastomeric epoxy caulk/grout in the crack. Don’t overfil. In my experience this caulk will self-level. It must stick to both sides of the crack to prevent weeds. Immediately clean any mess up. This stuff doesn’t come off easily when cured.

    Since epoxy caulk or grout really is not a do-it-yoursef item, you could use the following as something with a very long life. Note, however, that it is an industrial product, so even though it is made by Krylon, you probably will not find it at the neighborhood home center.


    And last, you could just use chemicals (regularly):


    Which is available at Walmart.