FLASHING is specially constructed pieces of corrosion-resistant metal or other materials used to protect buildings from water seepage. Flashing should be installed to prevent penetration of water and other moisture in the form of rain or melted snow at the junction of material changes, chimneys, and roof-wall intersection. Flashing should also be used over exposed doors, windows, and roof ridges. Figures 6-53 through 6-57 show areas or locations in which some type of flashing is required.

Flashing materials used on roofs may be asphalt-saturated felt, metal, or plastic. Felt flashing is generally used at ridges, hips, and valleys. However, metal flashing made of aluminum, galvanized steel, or copper, is considered superior to felt.

Figure 6-56-Flashing at roof and wall intersection: A. Wood siding wall; B. Brick wall.