Having detailed all the tips for laying synthetic turf on the ground or parking grids, we now want to address a specific case: Laying on a concrete slab. The realization of such a site, whether for a terrace, a balcony, or on any concrete base (or strongly supports: tiling, paving, leveling), does not present any difficulty. Here, we detail how to prepare the support correctly and achieve a professional installation.
Preparing The Surface Before Laying The Synthetic Turf
1: Thoroughly Clean The Concrete Surface
Remove pebbles, rubble, and dust. Use a karcher to eliminate all moss, mold, and invading micro-organisms that have clung to the concrete slab over time.
2: Check The Leveling
Perform a brief analysis to verify that the concrete slab is correctly leveled. Level off, scrape imperfections, remove impurities, small beads of concrete, or residual glue from old tiling make all those bumps that could deform the surface of the lawn disappear.
3: Check Slopes And Flow
Continue this brief analysis by observing how the water flows. The grass you are going to lay is completely permeable, and this permeability will not affect the flow of water in any way. If the water stagnates in places, forming what is called a “flash,” that is to say, a puddle, the presence of the lawn will not improve the situation. If necessary, you will need to make a light leveling which will fill in the hollows and allow you to readjust the slope correctly to avoid stagnation. Take advantage of this step to locate (and note) where the water is going when it drains from the slab.
4: Install The Synthetic Turf
Once the concrete slab has been properly prepared, you must roll out the grass directly on it. It is useless to place a geotextile on a concrete slab. Then you will make the cuts, the invisible connections between the strips (using pre-glued tape), and install the entire lawn on the surface it will occupy.
5: Take A Break During The Pose
At this stage, you will take a break of a few hours: before fixing the lawn, it is essential to let it work with the temperature differences so that it expands and “falls into place.” This intermission of 3 or 4 hours is essential. Whatever the medium, all poses require a break! And in the case of laying on a concrete slab which heats up quickly and more in the sun than any other support and it is even desirable to make this break last a little longer.
6: Glue The Grass To The Concrete
So that synthetic turf can continue to work with temperature variations over its entire surface, it must be fixed to the ground only on its periphery and this, whatever the support. You will therefore glue the edges of the concrete slab over a width of 10 cm. You will use a bi-component polyurethane glue (a mixture of resin and a hardener). Specific and professional, it is the glue best suited to resist year, temperature, and bad weather.
7: A Last Essential Point, The Flow Of Water
Warning: remember to create a passage for the water. You must leave sufficient space without glue at the place of the flow so that the water finds its way. Fortunately, thanks to the brief analysis carried out previously, you had spotted (and noted) the place.
A synthetic lawn finds its place wonderfully on balconies and terraces. These previous explanations break down the steps for laying artificial turf on a concrete slab, but all these tips remain valid for most hard substrates: tiling, paving, and leveling. Note again that fixing to the ground is not always necessary. For small spaces, for example, you can use heavy decorative objects (such as planters) to keep the lawn in place.
