The white liquid membrane on our roof has gotten dirty and developed hairline cracks. How is it renewed?

White liquid roof membranes stand out in the sun, dust and rain year-round. Over time the surface gets dirty — losing some of the reflectivityCool roof coatingA white or very light top coat that reflects much of the sun's radiation, so the roof and the floor below heat up less. that keeps the building cool — and develops local wear or fine cracksCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention.. If maintained before water gets underneath and blisters the old layer, renewal is straightforward.

First the roof is washed clean of dust and grime. Every crack in the surface is then sealed individually, along with the bases of vent pipes and the parapetParapetThe low wall around the edge of a flat roof or balcony. The joint between it and the floor is one of the most common places for leaks. corners.

Fresh coats of waterproof membrane (often a grey base layer followed by the white top coat) are then rolled across the entire floor and up the parapet walls, restoring both watertightness and a bright, reflective surface.