A 2 metre high solid fence has an extra 45% surface area on the post and batten side (e.g. if the front face of the fence is 2 metres high by 10 metres long then the surface area is 2 x 10 = 20m^2. the post and batten side would there for have a surface area of 20 x 1.45 = 29m^2).
Add 10.5% to the inistial surface area calculation (e.g. a corrugated iron structure 200m^2 will actually have a surface area of 200m^2 x 1.105 = 221m^2).
Based on a model of 1cm base (coarse texture), the surface area is two times greater than the base area. If the height of the pyramids is 0.5cm (representing a medium texture) the increase in the surface area is about 40%.
For Older buildings and houses, take teh floor area and add 40% (allows for soffits, roof pitch, corrugations and overhangs). With newer homes with small soffits allow floor areas plus 25%.
Rough Sawn Timber
For the given surface area, allow up to two times the amount of paint or stain for the first coat.
Unprimed weatherboards require priming back and front. Stained weatherboards require the first coat also to go all around. The total area of a (rusticated) weatherboard is 2 1/2 times the area that is shown when it is fixed.
Add 50% to the flat surface area.