Condition of surface

The condition of the previous coatings is one of the main factors affecting the specification of paints as the level of breakdown determines the amount of preparation required. For example, a recently applied decoration will have no breakdown and will only require a wash down and gentle abrasion before redecoration. A ten year old coating which has been exposed for some time will need thorough cleaning and preparation prior to painting and may even need to be totally stripped back to a clean surface.

It is therefore important to assess the degree of coating failure or, in the case of metals, how much the surface has corroded. For a full description of the degrees of coating failure, see the condition of surface table.

Sometimes, extra preparation or special mention to defects is necessary within a specification or paint schedule. See site work instructions for details of extra preparation (e.g. the removal of efflorescence) or for reference to specific practices (e.g.power washing of surfaces)

It is also advisable to read the prior to painting guidance notes which give an easy reckoning system for determining which clause or special area of guidance relates to the area in question.

If you find that the area to be coated has a painting defect where the cause of the defect is not readily apparent, refer to the FAQs in the Ask an expert section for futher guidance.