Fibre-cement cladding – impact damage

Cause

Stones, balls, human impact, vehicles

Repair

  • where the fibre-cement cladding is very old – installed before the mid-1980s – there is a possibility that it may contain asbestos fibres. Polite and Fibrolite are two examples of asbestos-cement cladding. If you are not sure whether a fibre-cement cladding contains asbestos, you can get a small piece (about the size of two $2 coins, or approximately 2 x 3 cm) tested at one of the labs listed on our asbestos page
  • if testing confirms the presence of asbestos, and the damage could result in fibres being shed into the air, we recommend you contact a licensed asbestos removalist for advice. You can find a registry of licensed removalists on the WorkSafe New Zealand website. Breathing in asbestos fibres can lead to serious and potentially fatal illnesses
  • for relatively new fibre-cement, or for older cladding where no asbestos has been found, small holes or cracks can be repaired by first removing all loose material and dust. Fill with an exterior grade polyester filler. Sand, prime and paint with a minimum 2 coats of good quality acrylic paint
  • for larger areas of damage in very visible areas of the building, replacing the entire damaged sheet is likely to provide the best solution
  • where the damage is in a location not visible, or a short-term solution is required, a patch could be applied. One option is to trim the damaged area to a regular shape, removing all loose or broken material. Cut a patch of cladding material to a size larger than the damaged area and fix in place with exterior grade construction adhesive and seal the edges with exterior grade flexible polyester filler or sealant. Sand, prime and paint with at least two coats of good quality acrylic paint
  • a second patch option may be possible in some circumstances. Cut two strips of fibre-cement and glue them across the top and bottom of the hole at the back of the cladding using exterior grade construction adhesive. (For a small hole, one piece fixed across the centre will be enough). Cut a third piece to fit neatly inside the hole and glue this in place against the backing fibre-cement pieces. Fill around the patch with exterior grade flexible (polyester) filler. Sand, prime and paint with a minimum two coats of good quality acrylic paint