Timber weatherboards too close to or in ground contact

Cause

Weatherboards were originally installed too close to the ground

Repair

  • aim for a minimum 30–50 mm gap between the base of the timber and the ground to prevent moisture uptake. The easiest way to achieve this may be by lowering the soil or garden level so it is clear of the cladding – the bottom of the cladding must be able to dry completely. Ensure that lowering the garden level does not lead to rainwater flowing under the house.

  • check for rot in the bottom weatherboards with a screwdriver. Try to push it into the timber – if the screwdriver easily enters the timber, then the timber is rotten

  • if rot is found, replace all damaged or suspect weatherboards with treated timber. Use H 3.1 timber with a 3-coat paint system or H3.2 treated timber

  • where timber is sound, allow it to dry out completely. Scrape off loose coating and sand the bare timber until the surface is sound. Seal the timber – especially the edges – and recoat with at least 2 coats of acrylic paint.

  • ensure good subfloor ventilation:

    • there should be not less than 3500 mm² of clear open subfloor venting for every 1 m² of floor area

    • ventilation openings should ideally be high in the subfloor space, near to the underside of bearers

    • vents should be spread evenly around the building perimeter to allow cross-ventilation

    • no part of the subfloor should be more than 7.5 m from a ventilation opening.

Cause

Gardens have been built up

Repair

  • lower the soil/mulch level so it is clear of the cladding – the bottom of the cladding must be able to dry completely. Leave a minimum 30–50 mm gap between the base of the timber and the ground to prevent moisture uptake. Ensure that lowering the garden level does not lead to rainwater flowing under the house

  • check for rot in the bottom weatherboards with a screwdriver. Try to push it into the timber – if the screwdriver easily enters the timber, then the timber is rotten

  • if rot is found, replace all damaged or suspect weatherboards with treated timber. Use H 3.1 timber with a 3-coat paint system or H3.2 treated timber

  • where timber is sound, allow it to dry out completely. Scrape off loose coating and sand the bare timber until the surface is sound. Seal the timber – especially the edges – and recoat with at least 2 coats of acrylic paint.

  • ensure good subfloor ventilation:

    • there should be not less than 3500 mm² of clear open subfloor venting for every 1 m² of floor area

    • ventilation openings should ideally be high in the subfloor space, near to the underside of bearers

    • vents should be spread evenly around the building perimeter to allow cross-ventilation

    • no part of the subfloor should be more than 7.5 m from a ventilation opening.

Cause

Path or paving has been laid against the cladding 

Repair

  • break up and remove concrete or paving. Reform the ground surface so there is a minimum 30–50 mm gap between the base of the timber and the ground and ensure that rainwater will flow away from the building

  • check for rot in the bottom weatherboards with a screwdriver. Try to push it into the timber – if the screwdriver easily enters the timber, then the timber is rotten

  • if rot is found, replace all damaged or suspect weatherboards with treated timber. Use H 3.1 timber with a 3-coat paint system or H3.2 treated timber

  • where timber is sound, allow it to dry out completely. Scrape off loose coating and sand the bare timber until the surface is sound. Seal the timber – especially the edges – and recoat with at least 2 coats of acrylic paint.

  • ensure good subfloor ventilation:

    • there should be not less than 3500 mm² of clear open subfloor venting for every 1 m² of floor area

    • ventilation openings should ideally be high in the subfloor space, near to the underside of bearers

    • vents should be spread evenly around the building perimeter to allow cross-ventilation

    • no part of the subfloor should be more than 7.5 m from a ventilation opening.