Lead Roof Corrosion

However some roofs have been subject to severe underside corrosion as a result of on going damp conditions and the presence of carboxylic acetic and formic acids given out.

Lead roof corrosion. Lead is the only metal generally considered to be compatible with zinc coated steel but not with zincalume steel or colorbond steel. The ease with which lead can be shaped and its resistance to corrosion make it valuable as the outer covering for electric cables. As lead has become much more expensive it is used for roofing less often than in the past and copper or plastics. More about lead as a building material.

Zincalume steel in contact with or receiving of run off water from lead is prone to corrosion. Lead and copper are the biggest culprits when it comes to shortening the service life of metal roofing due to corrosion. It protects the insulated wires inside without making the cable too stiff to bend. Hot water discharge pipes should be extended beyond the roof preferably to ground.

Most lead roofs are unaffected by underside corrosion or contain only a small amount of corrosion products possibly as a result of damp conditions when the roof was laid. Correctly laid lead roof greyfriars roofing note the height of steps between bays the rolled joints and adequate overlaps problems.