Coatings have been used to area and recover roofing techniques for lots of years. Many coatings used today have improved in efficiency in comparison to the first coatings used 30 years back. This progress is especially accurate relating to adhesion to a number of ceiling substrates, in addition to long-term functionality. Two necessary options that maintenance managers face well before any coating is placed are whether to first use a bitumen primer and bitumen paint to the roof area and whether to employ an aluminum coating as the top coat.
Bitumen primer and bitumen paint Decisions
Primers assist in the adhesion of the coating by giving a combination between the top surface and the coating. Primers come in a number of ways, thus the type of primer used relies on the substrate, weather situations, and the form of coating being used.
Managers should not make a decision to apply a bitumen primer and bitumen paint without speaking to the maker's specifications for the specific coating and substrate. A primer is in no way a replacement for suitable roof-membrane groundwork. The substrate should be clean and dry before the coating use. Workers should remove mud, chalking film, bitumen exudate, greases and oil prior to application.
Surfaces that usually need bitumen primer and bitumen paint consist of: metal flashings, gravel stops and other metal edging; concrete and masonry roof decks; masonry walls and floors; and gypsum and several other permeable areas. Asphalt primers should be employed with asphalt elements only.
Primers are suitable with modified bitumen goods, yet managers should examine manufacturer opinion before using a bitumen primer and bitumen paint. Though primers commonly operate perfect on clean up dry surfaces, asphalt emulsions primers can be employed to damp, not wet, surface areas. Primer and surface-coating application should occur in short order.
Matching Primers and Roofs
Administrators can use these generic recommendations regarding the application of bitumen primer and bitumen paint to many different kinds of roofs.
ASPHALT ROOFS. These rooftops, which include smooth-surfaced built-up or modified bitumen membranes, include light oils called exudate, which can depart a membrane shortly after its use. This approach is typical, and the exudate commonly will wash off the roofing after rainstorms. Any exudate on a ceiling prior to coating use should be cleaned up totally. Specific primers to forbid the exudate from bleeding through clean coating might be required with usage of acrylic coatings.
Glaze-coated built-up ceiling also can discharge exudate. If the glaze coat is not backed, it will crack. One method to reduce this influence on new rooftops, and to cover cracks in older rooftops, is to prepare the roof with a layer of fiber-supported asphalt-emulsion coating just before implementing the reflecting coating.
On old, weathered asphalt roofs, lots of coating producers propose using a bitumen primer and bitumen paint after cleaning up the membrane to make the area for coating. When coating a present aluminum roof with an acrylic coating, priming usually is required. Supervisors should speak to the maker for suggestions.
METAL. Primers usually are suggested prior to employing a surface coating to a metal roof, regardless of the top's age. Particular primers are formed for both aluminum asphalt and elastomeric coating usage over metal roofing. Some primers, like zinc-chromate-based primers, may be incompatible with a number of coatings. Using a bitumen primer and bitumen paint is not a substitute for removing rust and scale on weathered metal top.