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You’re tired of your concrete patio’s boring look so you want to replace it with a beautiful lush grass. But will the concrete under the lawn allow the turf to thrive?
What about factors such as soil moisture and root development? All necessary for a healthy bright green grass? How about artificial turf – if placed over a concrete patio would the drainage be a problem? Let’s answer all the questions.
Can laying grass on concrete be a successful long-term project?
Putting a little soil over the concrete surface won’t do the job. The grass needs to establish its roots properly. Concrete is solid, it easily heats up in the summer and isn’t as porous as soil. With that in mind, to answer the question of whether laying turf on concrete is possible:
Yes, it can be done, but only with artificial turf, because there is no need for plants support this way. The synthetic grass will fit well on the concrete and won’t require additional maintenance.
Using real grass is highly undesirable as it will most likely have issues with staying alive. The concrete underneath will hinder the soil’s moisture-retaining properties. Also, proper drainage will be a serious problem. If you absolutely want real turf, it is really best to hack out the concrete first.
Laying Artificial Grass on Concrete (and other hard surfaces)?
Things to consider when laying synthetic grass on concrete:Laying synthetic grass on paving slabs or pure concrete is easy and doesn’t require much maintenance afterwards.
- Installing a shock pad to soften the surface is usually part of the process. It also has the property of smoothing out slight imperfections (a flat surface is needed for installing the artificial turf). If you are a cat or dog owner note that a shock pad is not recommended, because the urine bacteria tend to stay in the underlay. Learn more about preventing cats from pooping in your garden.
- A couple of holes need to be drilled in the cement for a better drainage (in case of puddles forming thereafter spraying it with a hose). After all, you don’t want ponds in your yard after every rainfall.
- A slight gradient may be enough for the water to run off, but it really depends on the condition of the yard itself.
- Larger gaps in the concrete should be filled in before the turf laying as they will result in sagging and a poor overall quality of the job.
Laying artificial grass on UNEVEN surfaces such as paving slabs
The desired surface for your astroturf should be flat and smooth. Gaps between the slabs should be ultimately filled with some sort of medium.
If the imperfections are small, a foam underlay will be enough to correct them. If you have weeds growing between your block pavings, use a weed killer and manually remove them. You should then install a weed-suppressing membrane.
If the bumps and gaps are too pronounced, however, you’d need to fix that before installing the artificial grass. Here is how to prepare uneven concrete or paving for artificial grass laying:
- Use a layer of sharp sand and level it – you need to compact the sand first, which is best done with a vibrating plate compactor. After that, you need to manually level it. Don’t forget to leave spacing around the perimeter where you will later apply adhesive. The glue is usually waterproof which will keep rain away from washing off any sand.
- Use a self-levelling compound – this is a type of cement that is especially used in levelling concrete. It’s used prior to installations of different types of flooring as they all require a flat surface. Follow the manufacturer’s instructions and you won’t have any issues applying it.
Issues around real turf and shallow soil
If you really can’t agree on removing the concrete and insist on using real grass, then you won’t have it easy. Real turf over a concrete foundation will need a minimum soil layer of 25 cm. You should choose a shallow-rooted species as well. The roots need to find their nutrients and water deep down in the soil. Even then you’d need to drill holes in the cement base (every foot or so) to improve the drainage. If the patch doesn’t drain well the water will prevent oxygen from entering the soil and your turf will die out real quick. Apart from that, you’d have to water it profusely (every day) during warm summer days. The water will evaporate very quickly in such a shallow patch of soil. A fertiliser should also be used as the grass won’t be able to feed off the soil’s nutrients.
Do leave a comment below if you feel you need more answers!