Weatherboards and Cladding Know How

Tips to Maintain Weatherboards After Installation

Important: Timber weatherboards should not be installed if their moisture content is outside the range of 14 - 18 %

It is the building owner's responsibility to ensure that the cladding system receives regular maintenance so that it continues to perform at its required level.

Maintenamce Interval

For most areas (especially coastal, bush covered and inner-city area) maintenance should be performed at laest once every 6-12 months. Maintenance may be required as often as once every six months, depending on the level of pollution, dirt in the environment. 

or sheltered, inland locations, maintenance should be performed once every 12-18 months. 

Maintenance Requirements

Regular maintenance is to include the following 5 steps:

  1. wash all the exterior surfaces with low-pressure water to remove dust, dirt and other contaminants; a). Extra attention should be given to areas that are not exposed to rain such as sheltered areas below eaves;b). Do not direct high pressure water at any part of the cladding systemas this may damage the timber surface. take care especially around sensitive junctions such as joinery surrounds and other flashings where you must avoid forcing water past anti-capillary gaps and falshings in to the wall cavity.
  2.  Use a soft bristle nylon brush or broom with water and an appropriate cleaning agent (refer to paint manufacturer for correct cleaning agent specific to their paint system) to remove stubborn or persistent dirt and surface contaminants. Rinse thoroughly with water after cleaning operation to remove any excess cleaning chemicals. Do not use aggresive cleaning chemicals and always ask advice from Timspec/coatings supplier.
  3. Inspect all the surfaces and junctions for signs of damage, wear-and-tear, or coating breakdown. Where coating surface has broken or eroded (oils/stains) remedial action required: a). remove all damaged or loose coating (may involve sanding back to solid timber); b). Spot prime any bare timber (if repaiting paint); c). Ensure the timber is fully dry; d). recoat with minimum two coats of the product originally used to initially overcoat the timber.
  4. Repairing or replacing any damaged or deterioreted items in order to preserve the weathertightness of the building. a). Small isolated areas of dry rot (highly unlikely) in timber can be cut out and filled then primed and coated; b). For larger areas of deterioration: remove and replace either the damaged section or the entire board for nay deteriorsted timber boards (includes scribers, cover boards and weatherboards). prime and coat the replacements as required; c). Other items (soakers, flashings and cappings) may need to be replaced in their entirely.

Important points

Correct Nail Placement

Ensure nail fixings are placed correctly in accordance with selected profile. A single fixing per board at each fixing point. Nail placement is to be maximum 10mm in from the side of the rebate (35mm from the top lap of weatherboard). Ensure nail does not penetrate lower underlapping board. 

Nail on Upwards Angle

All weatherboard nails should be installed on a 5ยบ upward slope so that no water cannot run down the nail through the cavity.

Weatherboard Nails Must Never Penetrate a Flashing 

Flashings provide a secondary line of defence at critical points, by nailing through the flashing you provide a clear path for water to tract along.


Weatherboards will require predrilling for pilot holes before nailing to reduce th erisk of splitting

Check What Treatment your H3.1 Pine Is

ACQ and CuAz treatments are more corrosive than CCA and should not beused in contact with galvanised metals. Thsi means that ACQ or CuAz need stainless steel nails. Also, regardless of the treatment H3.1 timber should not be used where it contacts galvanised falshings  (use aluminum, stainless steel or uPVC)

Plain Head

ork out your weatherboard spacing before you start nailing board up. Ensure correct setout of boards. On eboard on any given wall elevation may need to be cut down to fit wall width. Donot extend or reduce the 25mm lap requirement or 'creep' the board to fit.

Cavity Battens must Direct Water Outwards

Ensure the sloped top edge of cavity battens directs water outwards (away from the framing).

Trim One Side of Battens Only

When trimming cavity battens (often required at joinery heads to allow for flashing tape and cavity base closure) make sure you only trim off the side that will be going against the framing. The 20X7mm cut-outs need to be full-sized on the side facing outwards (against weatherboards) to allow for drainage.