High-quality, 100% acrylic paint can give a service life of up to 10 years or more when applied to specification on correctly prepared metal surfaces. This lifespan will vary with colour, roof orientation and the aesthetic requirements of the situation. Poor paint curing will downgrade durability.

For many paints, a 50µ dry film build is required to achieve optimal thickness, and typically this requires two layers of top-coat.

Paint should not be applied on wet days when condensation has not completely dried, or when ambient temperatures are expected to reach less than 10° or more than 30° within the drying period. Windy days are also not recommended, as curing is impaired.

Ridge ladders should be fitted with protective buffers or rubber pads as they can cause abrasion damage to pre-coated metal cladding. Where it is possible the painter should walk in the pan, but when it is necessary to step on the rib, (only at the purlin line) attention should be paid to sheet overlaps as these may spring up after a painter's weight is removed and reveal an unpainted line.

Decking profiles have a tight roll-formed bend at the top of the upstand and care is necessary to ensure the specified film build is applied in this area.

Brush Application:

The use of nylon brushes is advisable, and these should be wetted with water prior to use to avoid clogging, and in warm weather should be washed out completely at every rest break, or wrapped in cling film and refrigerated.

Roller Application:

Roller application is not preferred for profiled metal roofing as it tends to apply an uneven paint film thickness. The combined use of brush and roller can give good results with tray profiles.

Dampen the roller prior to use, apply with even pressure, and do not over-roll.

Spray Application:

Spray application in the hands of a skilled applicator can achieve the most consistent film builds. However, airless spray equipment can produce very high film builds giving rise to runs and uneven coatings. When using spray equipment on hot or windy days, the paint spray may dry before it has reached the metal, which leaves a sandy appearance and feel. This is not aesthetically acceptable and will not provide the even coating or durability required.

Clause Number: 
Revision Category: 
3 - Substantial change to recommendation
Revision Detail: 

This clause has been renamed and completely revised during the overall revision of Maintenance, previously independent clauses have also been incorporated. They are:

Draft Clause: