Like all natural decking, Thermory® will begin to gently weather down once installed. This will include an attractive silvering/greying and the development of small, surface hairline cracks. Whilst many prefer to allow this appearance to develop, it can be checked through the regular application of Thermory® Thermo-ash oil. The boards can be sanded back at any time to restore the original tones. The surface should be kept clean of leaves, pine needles and any debris that can hold moisture and attract mould and mildew. Barbecue spills, wines, condiments, dog nails, high heels, etc. can stain and scratch the surface. Most of these will fade and become less noticeable over time. Deeper scratches and stains can be blended with a light sanding.