Waimauku is north to Kumeu. We happen to finished one Kumeu sleep out room painting then our team moved over to complete this roof painting in 6 days.
The left is the difference before and after the water blasting. The house is hidden in the bush. The color steel roof was cleaned completely, it took one guy a whole day.
Many different metals are used for roofing. Copper, which over time develops a signature green patina, is found in many older cities, especially on prominent ecclesiastical, university or government buildings. Tin roofs common on farm buildings are actually more likely to be corrugated galvanized steel. Other metal roofs are not always recognizable. Terne, which is steel coated with an alloy of tin and lead, is usually painted.
Some modern aluminum roofing is die-stamped to look like wood shingles, and some steel roofing panels are preformed to resemble clay tiles. Most metal roofing features some sort of contoured or formed edge that overlaps the edge of an adjacent piece to create a water-shedding joint. Corrugated panels simply overlap a crest and trough. Flat roofing panels have standing seams along their edges that are crimped tightly to connect them to each other. Copper ranks high in durability; properly installed, it can last a century under the right conditions. Other roofing metals are more subject to corrosion, but even aluminum and galvanized steel can last for decades. Salt air is very corrosive to metals, but a more common factor in metal roof failures is a destructive chemical reaction, called electrolysis, that occurs when dissimilar metals contact one another. For this reason, it’s very important to install metal roofing using fasteners made of the same metal.
Painted steel or terne roofs must be repainted and touched up to prevent rust. Pinhole leaks can be fixed with roofing cement or an asphalt-based sealant. Larger holes or tears can be mended by soldering on a patch of the same metal. Steel and terne should be soldered with a noncorrosive resin flux; copper should be soldered with an acid flux. Aluminum roofing does not need to be painted, but it often is for aesthetic reasons. Fasteners are usually screws with sealing washers, as nails tend to loosen over time.
Soldering a Patch
- Clean damaged area thoroughly. Cut a patch of the same metal at least 5cm larger in each dimension than the hole. Snip corners and fold edges under 12mm. Sand the turned edges and position the patch. Coat edges and the roof surface with flux.
- Weight the patch with bricks to secure it. Use an electric soldering iron to heat solder at the edges of the patch until solder flows into the joint. Work around the patch until all the edges are sealed.
Coating a Pitted Roof
Over time, the slow corrosion that occurs with metal roofing often results in numerous pinholes or pits that will grow and allow leaks. Modern, factory-applied protective coatings ward off this damage for many years, but once the degradation starts it’s almost impossible to stop. You can, however, buy some additional time by applying an asphalt-based liquid sealant. Start at the high end of the roof and work the coating along the flats and seams using a stiff push broom. Work from your ladder to finish the lowest sections. As long as the coating adheres well to the metal surface, periodic coating will help prevent leaks, but eventually the roofing will have to be replaced.
- Cut two patches from fiberglass screen material, large enough to cover the damaged area. Use a wire brush to scrub the roof surface clean, and then coat the area with roofing cement.
- Apply one fiberglass patch over the fresh roofing cement. Using a flexible putty knife, cover the patch with more cement. Then embed the second fiberglass patch in that layer. Finish with a third coat of cement.