Our outdoor concrete stairs leak into the storage room or space underneath. How are the steps waterproofed?

Underneath outdoor concrete stairs there is often a storage room, boiler room or ground-floor entrance. Because the staircase stands out in the rain and sun and is made up of dozens of inside and outside corners, water sits along the joints between treads and risers and seeps through hairline 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. in the concrete.

On this outdoor staircase, the worn concrete steps were letting damp through. The surface was cleaned and prepared, and successive waterproof coats were applied.

The coating was worked continuously across the horizontal treads, the vertical risers, the nosings, the side wall junctions and the landing floor at the foot of the stairs.