Timber trims – rotting battens or cover boards

Causes

Timber is or has been continuously damp

Inadequately treated timber

Non-durable or untreated timber used

Common

Listed under: Exterior, timber and wood-based, timber, cladding, walls, moisture, durability, rot, wall cladding, timber trims

Cause

Timber is or has been continuously damp

Repair

  • determine and address the cause of continuous dampness of timber. If there is a broken rainwater gutter above it, repair or replace the gutter. If there is dense planting close to the house, prune it back or thin it out to allow air movement

  • remove damaged boards. If replacement timber is radiata pine, it must be treated to H3.1 and be be fully primed (including the back of the board) before installation and given two coats of paint after, or H3.2 if installed unpainted or stained

  • nail with single fixing in the centre of the batten

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Cause

Inadequately treated timber

Repair

  • remove damaged boards. If replacement timber is radiata pine, it must be treated to H3.1 and be be fully primed (including the back of the board) before installation and given two coats of paint after, or H3.2 if installed unpainted or stained

  • nail with single fixing in the centre of the batten

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Cause

Non-durable or untreated timber used

Repair

  • timbers such as western red cedar and heart macrocarpa may be untreated but they must not be continuously wet in use. If timber is continuously wet, address the causes of this first

  • replace damaged boards

  • nail with single fixing in the centre of the batten

  • prime all surfaces including the back if timber is to be painted. Paint with a minimum two coats of good quality semi-gloss or high gloss acrylic paint

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