Laying Artificial Grass on Concrete

In a lot of cases, people laying artificial grass are doing so as a direct replacement for a natural lawn. We’ve covered that in our other guide on How to Lay Artificial Grass [link], but it’s also a popular way to liven up an old patio or concrete surface. Luckily, it’s also incredibly simple to do. This process also works with wooden surfaces like decking, as long as the gaps between the boards are small.

What you’ll need to lay artificial grass on concrete

• A sharp knife with spare blades
• Tape measure and/or straight edge
• Shovel
• Joining tape 
• Gloves and knee pads (or a garden cushion)
• A stiff broom
• Compactor plate or roller
• Artificial grass adhesive

What to consider

The main thing about laying artificial grass on top of concrete, stones, or paving is whether the surface is good enough and whether there’s adequate drainage.

Is the surface in good condition?

Undoubtedly the most important question. To be able to lay artificial grass on concrete or paving, it needs to be mostly flat, stable, and without major cracks. 

By major cracks, we mean anything that is wider than 20mm. If a crack is this big then there is likely more damage that you can’t see and it’s not wise to install artificial grass over it. Smaller cracks can be filled with self-levelling compounds during the process, and these shouldn’t be a major issue.

It’s also important that the concrete or the paving is stable. If there are any wobbly slabs or stones, or the concrete itself is damaged, loose and coming apart, then it’s not likely to be able to take an artificial lawn on top.

Finally, some small undulations on the surface are also not an issue. You can lay artificial grass on uneven concrete as these bumps can be remedied later in the process with sand and compounds. However, large bumps or depressions are again likely to cause problems. Anything less than 20mm above or below the main surface should be able to be rectified with sand but anything higher is likely to cause problems with the artificial grass.

If you think you’re unable to lay artificial grass on your existing concrete or paving, you should take it up and either lay a new solid base, or follow our guide for the more ‘traditional’ way to lay artificial grass [link].

Drainage

Drainage is another thing to consider. Although artificial grass holds water well, if the existing surface doesn’t drain well and holds the water, it is not ideal to lay turf on top of it. The only real way to check is to wait for good ol’ British weather to do its thing. If not, a hosepipe will do the trick.

Unless the puddles are significant, it won’t be an issue, you can simply drill some holes to allow the water to drain away.

How to lay artificial grass on concrete

1. Start by cleaning the base with a hose pipe and a stiff brush. If you’ve got a power washer that’s even better. Make sure you get rid of as much dirt and debris as possible.
    
2. Now’s the time to sort the drainage. If your base already drains well then there’s no problem but if it doesn’t, drill some holes or channels to allow water to run off. If you’re building your concrete base specifically for artificial grass, ensure it’s built with a very slight gradient.
    
3. Fortunately, as you already have the concrete base in place, you won’t have to do much measuring. Begin by laying down your foam underlay. This is a vital part of putting artificial grass on concrete. First, it will smooth over any smaller bumps or cracks and secondly, it makes the grass feel more cushioned and softer underfoot.
   
   We recommend choosing a foam underlay of at least 5mm, but we find many people opt for 10mm thickness.
   
   If you’re laying artificial grass on paving or stones, you’ll need to spread a layer of sand to fill in the gaps before you lay the foam. If you need to fill any cracks, then now is the time to do this too. You can join the foam with most sorts of masking tape.
   
   Glue the foam down and allow to dry.
    
4. Now you can lay the artificial grass over the surface. Unroll it, offer it up and cut to shape, leaving around 50mm of overhang on each side. Remember to flip it over and cut from the back, getting as close as possible to the stitching but without cutting through it.
   
   Tapi Top Tip: Lay the artificial grass with the pile pointing towards your home, or the area you will be spending most time for the best look.
    
5. Allow the artificial grass to rest in place for at least 2-3 hours, even overnight if possible. This allows any creases from storage or transportation to work themselves out, and it should return to its true shape. Once it’s settled down, you can
    
6. If your area is big, you may have to join two pieces of artificial grass together and now is the time. For more information on how to join artificial grass, scroll further down.
    
7. Now’s the time for the adhesive. Apply a suitable outdoor adhesive around the edges of the artificial grass and bond them to the base. It pays to have a couple of extra hands during this stage. For decking, you can also use carpet tacks to fix it down.
    
8. When you’re applying the adhesive, it’s important to leave gaps in the glue to allow water to drain. We recommend leaving some small gaps in the adhesive periodically to assist with drainage. Make sure these are no more than 20mm to assist with drainage.
    
9. Allow the adhesive to dry according to the instructions before walking on the artificial grass.
    
10. The final step is to apply the sand infill. Sand infill helps to keep the fibres of the pile upright and dissipates heat during the summer months. Simply spread this out and use a stiff brush to work it into the pile, brushing against the grain.
     
11. Have a cup of tea, or something stronger, and admire your new artificial grass.

Your artificial lawn should last decades with proper care. For more information, refer to our Artificial Grass Care Guide.

How to join artificial grass

Earlier in the article we mentioned you may need to join your artificial grass. To do this, you need to buy joining tape and adhesive that is suitable for outdoor use.
 

1. Unroll your artificial grass into the correct position on the ground.
    
2. Line up your two pieces of artificial grass and cut away any excess so the stitching is as close to the new edge as possible.
    
3. Offer up the grass and create a dry join to check the fitting.
    
4. Roll the joining tape out underneath so that it covers equal amounts of each piece of turf.
    
5. Roll the turf back temporarily and apply the adhesive to the tape. Apply in a zig zag fashion and use a spreader to ensure it’s all covered.
    
6. Work your way down the seam pushing the two pieces of turf together, making sure you’re not trapping fibres or anything else between the join.
    
7. Once you’re happy with the join, lightly brush over it to seal it and allow it to dry.

For more information or advice about how to fit artificial grass, please don’t hesitate to contact us.