Do it yourself paving slab laying
Preparation of the working area:
Preparation of the working area is an important stage. A quality substrate is the key to the success of all other works; therefore, works on the preparation of the ground needs to be carried out first:
- Remove the upper layer of the soil to make a trench depth of 20 cm. This indicator is conditional – there are no universal solutions. The depth of the trench depends on a number of characteristics: a soil composition and its freezing depth, groundwater level, lie of the ground. For solid soil, 20 cm is sufficient; for loose soils, the depth should be increased. The average depth for walkways – 20 cm, for a parking area or driveway the trench needs to be deepened by another 7-10 cm.
- From the bottom of the trench, carefully remove stones, roots of grass and plants; then wet the ground with a watering can or hose, and tamp it with a rammer to prevent further ground subsidence.
- Lay out geotextile or agrofabric on the bottom of the trench. They will not retain water, and will prevent remaining in the soil roots and seeds to germinate and damage the path. In addition, geotextile will prevent the interpenetration of mainland soil and sand.
Curbs are the constraints that provide a structural support to the pavement edge. To install them, along the prepared trench there should be dug out grooves, the bottom of which should be reinforced with crushed stone. The voids in the crushed stone are filled with sand. Curbs are placed on a gravel level and fixed with cement-sand mortar. Do not grout all the curbs with ready-made mortar at once – each should be reinforced individually with a concrete lock. Upon completion of the works, the height of the curbs, to ensure good drainage, should be flush or 10-20 mm below the upper edge of paving stone. The height is primarily regulated by the depth of the dug grooves. Drying of the concrete locks takes about 24 hours; then the grooves with curbs are backfilled with soil – to the general level of the bottom of the trench.
Geotextile should be covered with a coarse sand layer – up to 5 cm. Its surface should be levelled with a rake and be wetted with plenty of water. Before the next stage of the work, in case of cloudy weather, it is necessary to wait 24 hours; in sunny weather 2-3 hours is enough. Then the surface should be levelled with a profile or pipe, and be covered with 10 cm layer of thick crushed stone. The crushed stone should be pressed with a rammer. Do not lay the crushed stone exactly on the geotextile in order to avoid damage to the latter. Another 5 cm of sand is spread on the crushed stone in order to fill all the voids. This layer is needed for guttings and bringing the base to zero. The surface should be rammed again, watered (thus the sand will partially settle between the gravel) and levelled. As a result, there will be a perfectly flat substrate on which to lay the slabs.
Do it yourself technique of paving slab laying:
How to properly lay paving slabs on the sand?
In order not to tread on the rammed sand, paving slabs are laid in the direction away from the master. The master, being on the already laid surface, lays the paving stones in front of him, slightly pressing it into the sandy base, and moves forward stepping on the put paving stones. The horizontality of each row is checked by building level, using a rubber mallet. Using sand and a trowel, the surface is adjusted:
- if a paving slab is over the rest slabs, it can be deepened by tapping the rubber mallet or removing a layer of sand under it;
- if a paving slab, compared to the others, is placed too deep, it should be raised in order to increase the substrate level. For cutting the paving slabs, use an angle grinder.
but if you cut a paving slab completely, crakes may appear on it. Therefore, you should just make an incision by the angle grinder, and then the paving slab should be gently split up.
To prevent the paving slabs from shifting, they should be fixed with sand so that all the gaps are filled. The sand should be evenly spread with a brush or broom, and then the surface is watered to condense the filling. The procedure may need to be repeated 2-3 times, and later on after heavy precipitation. The gaps are sometimes closed up using a mixture of sand and cement, and then they are watered to strengthen the cement and better link the slabs. However, such a technique impairs moisture penetration into the drainage; therefore, it is impractical to use it on private areas and low-traffic lanes.