Cleaning Blackened Clay Roofing Tiles
- Procedure code:
- Gra Research File - Clay Roof Tile
- Thermal and Moisture Protection
- Clay Tiles
- Last Modified:
CLEANING BLACKENED CLAY ROOFING TILES
A. This procedure includes guidance on cleaning blackened
clay roofing tiles.
B. Clay tile may become discolored or blackened due to any
of the following:
1. Dirt build-up from air pollutants
2. Organic growths such as lichen, algae or moss
3. Industrial pollutants
A. Household detergent, household ammonia, weed killer, or
mixture of zinc or magnesium and water.
B. Clean, potable water
A. Stiff bristle brush
C. Garden sprayer/garden hose
D. Medium or coarse long handled vegetable fiber brushes
A. Surface Preparation:
1. Sweep down tile to remove dirt and debris. Use a
long handle broom or brush with more rigid bristles
which do not scratch the tile surface.
2. Pick up and bag the debris washed from the tile
such as leaves, dirt, and other litter from the
gutter and clean gutter at the same time.
3.02 ERECTION, INSTALLATION, APPLICATION
A. For Dirt and Pollutant Crusts: Scrub the tile by hand
with water and a stiff bristle brush.
B. For Organic Growth:
1. Remove growth with a stiff bristle brush and clean
2. Apply detergent, household bleach, weed killer or
use a solution of zinc or magnesium and water.
3. Rinse thoroughly with clean, clear water.
C. For Industrial Stains: Clean with a water-based
household detergent and a stiff bristle brush.
END OF SECTION