Fences and gates – fibre-cement panels cracked

Cause

Impact damage

Repair

  • replace the fibre-cement panels as required, determining first what type of product they are. (There are some proprietary products on the market, such as composite fibre-cement panels designed for reducing sound transmission.)
  • at the same time, ensure the timber framing supporting the panels is strong enough and the posts are no more than 2.4 metres apart – solid panel fences take the full brunt of wind compared to some other fence types
  • paint the new panels with a good quality self-priming exterior paint system
  • although it is unlikely there will be many fibre-cement panel fences remaining from the 1980s or earlier, try not to do anything with very old panels that creates dust, such as cutting them or breaking them up. Up until the 1980s, some fibre-cement panels used in fencing included asbestos. See here for more details

Cause

Timber frame movement

Repair

  • fence rails or capping timbers may warp or move. Where the problem is minor, additional fixings to posts may be sufficient. Use hot-dip galvanized nails with an annular grooved shank, or stainless steel in very corrosive environments (close to the sea or in a geothermal area)
  • where additional fixings are not sufficient, or timber is permanently warped, consider replacing the support timbers with new, larger rails. H 3.2 radiata pine rails in different dimensions are readily available.
  • timber frame movement may be made worse if fence posts are more than 2.4 metres apart (or 1.8 metres where a strong fence is required, such as a hilltop or otherwise exposed site). If posts are further apart than this, reinstall existing posts closer. Posts should be set 750 mm into the earth, with concrete around the base
  • replace the damaged fibre-cement panels and paint with a good quality self-priming exterior paint system

Cause

Panels at the end of their serviceable life

Repair

  • see the first repair above

Cause

Insufficient framing behind

Repair

  • where timber rails, capping or framing is insufficient, consider replacing the support timbers with new, larger dimension timber. H 3.2 radiata pine products in different dimensions are readily available. Fix to posts with hot-dip galvanized nails with an annular grooved shank, or stainless steel in very corrosive environments (close to the sea or in a geothermal area)
  • replace the damaged fibre-cement panels and paint with a good quality self-priming exterior paint system