Geotextiles

These blanket-like materials - which are not waterproof -  are used to stop flexible liners being penetrated by sharp stones and the like. Old carper or underlay, if non-organic and non rotting, can be used for the same purpose when savings have to be made. Geotextiles is available in various strengths, which are indicated by the weight of material per square metre. Generally, the greater the weight, the stronger and safer the product.