How to cover exposed aggregate concrete patio
An uneven surface only needs to be levelled before laying rubber tiles where larger depressions prevent even support or interfere with water drainage.
Minor unevenness, fine cracks, narrow joints and shallow defects are generally unproblematic. Tiles made from PU-bound rubber granules are elastic and flexible; their compliance depends on tile thickness and density. Thinner rubber tiles conform particularly well to a slightly undulating substrate.
Rubber tiles are suitable as a covering for an uneven surface and remain stable on uneven ground. Rigid concrete or stone slabs may rock on an uneven surface.
Pronounced hollows where water collects should be filled before installation. On a firm sub-base, accurately cut pieces of roofing felt can be used for filling and, where required, laid in several layers.
Sand, grit and gravel are unsuitable for local levelling because loose fill can shift over time.