Separate symptoms from causes
A damp mark may result from condensation, water ingress, rising moisture or a services fault. Each needs a different investigation; paint and stone are not a diagnosis. Review roof, junctions, drainage and ventilation with a specialist before approving finishes and closing the estimate.
Choose for exposure and maintenance
Exterior materials must suit their exact location, sun, water exposure and upkeep. Request samples and manufacturer guidance for the intended use. Terraces, pool, garden and outdoor furniture are distinct work packages, not a free extension of an interior price per square metre.
Write durability into the specification
For exterior finishes and fixings, ‘coastal suitable’ is not enough: require the manufacturer's guidance for the exact application. Specify substrate preparation, fixing system, protection, cleaning and inspection. Indoors, check ventilation of wet rooms and equipment access. On-site samples help with colour, but do not replace technical data sheets or specialist assessment of complex details.