Taking Care of Your Metal Roof
It's wise to clean your metal roof periodically, preferably once a year. By giving your roof a good cleaning you will enable your roof to perform at maximum performance. By picking up the dust that naturally settles on your roof, you help prevent discoloration that may occur if the roof is exposed to dirt-laden atmospheres for extended periods of time. A light cleaning is easy. Here are two options:
1. Dissolve one cup of Soilax or Tide, or other common detergent, in five gallons of warm water.
2. Dissolve one cup of household ammonia in room temperature water.
Wash the roof with one of these options using a soft sponge, or use a low-pressure spray washer. Follow with a thorough rinsing of plain water.
To Remove Dirt:
Dirt, chalk and loose mildew can be removed by the use of regular household soap solutions. Heavier dirt accumulations may need to be removed by the use of a dilute solution of trisodium phosphate, and excessive mildew may be treated with a dilute solution of common bleach. (NOTE: Never blend cleansers and bleach.) Rinse the surface thoroughly to remove any of the agents used in the cleaning procedure. Tide is a common solution to use. Mix one cup Tide to five gallons of warm water.
To Remove Wax:
There may be a layer of factory-applied wax on the surface of the siding. This is applied to protect the material during travel. If the wax is not removed the material will not adhere correctly and eventually may peel or flake off. To remove the wax, wipe the surface with a rag saturated with Xylene (Xylol). This industrial solvent will help remove the wax and assure adhesion between the substrate and the repainted material.
To Remove Surface Imperfections:
Minor scratches can be lightly sanded or buffed to create a smoother surface. Be careful not to sand too hard and expose the substrate.
To Repair Exposed Metal and Rust:
Exposed metal must be treated to prevent rust from occurring. Sand the area lightly and use a high-quality primer (Glidden Galvanized Metal Primer #5229, PPG Galvanized Steel Primer #6-209, or Dean and Barry Latex Galvanized Metal Primer) to protect the exposed metal from corrosion. Allow to dry before applying the topcoat. If either red or white rust is evident scrape or brush away as much rust as possible and then sand lightly, removing all rust before proceeding. Where large areas of rusting or surface imperfections are evident, the relative economy of power brushing or sand-blasting should be considered. Sandblasting with 16-35 met sand will provide a commercially clean and well-abraded surface for painting. If you do sand-blast, make sure that all dust from the abrading process is removed before priming the substrate.
General Surface Condition:
The surface to be re-coated must be abraded enough to ensure adequate adhesion. If the baked enamel finish is too smooth, the repaint material will not adhere to it, and it is advisable to test a small area of the building to evaluate adhesion. If poor adhesion is observed, the surface must be "roughed-up" by sanding (#400 met recommended) or power washing. It is imperative that the enamel finish itself not be removed during the process.
After you have taken the necessary steps to prepare the area to be painted, paint a direct to metal epoxy primer on. After the primer has fully dried, apply a compatible top coat. The primer and topcoat may be purchased from any major paint retailer. Follow the manufacturer's instructions for application techniques and cure time.