The AWCI Queensland provides this basic Home Owners’ information for flood affected linings regarding assessment and different processes involved in rectification.
Where the dwelling has been inundated with flood waters, it will be most likely that affected plasterboard will need to be removed. In many cases it will be obvious where plasterboard has been soaked or contaminated, however seek the advice of a professional tradesperson to assess the necessary actions.
Over-eager early action, may remove more plasterboard than is necessary, so the following information is provided as a guide to assist. If rectification work is to be claimed through insurance, ensure you contact the insurance company and assessor to determine appropriate rectification actions.
For this work contractors may use their own quotations or alternatively The Queensland Building and Construction Commission has a free contract designed for natural disasters, where the damage exceeds $3300, which can be found by looking up:-
“QBCC Natural disaster repair contract”
The contractor will not commence work without one of the contracts mentioned above signed, and/or a letter of authority from the Insurance Company to commence work.
- Identify the type of lining – Plasterboard, Fibre Cement Sheet*, Timber, Fibrous Plaster. Plasterboard may need removal from the level of inundation. Timber and Fibrous Plaster may not require removal and may simply require bleaching and washing down.
- Identify the safety hazards, sharp materials, nails, electrical, etc and use appropriate Health and Safety procedures.
- Draining any water from cavities is necessary before being able to assess the repair/replace requirements.
- Where the board has attracted mould and has not been inundated, then a propriety cleaner containing bleach or similar may be used. This is usually all that is required to keep the mould at bay; however oil of cloves can provide a longer residual mould inhibition giving a more lasting result.
- Plasterboard that has to be removed should be taken to the nearest board joint above the inundation level. Depending on the width of the plasterboard, this will either be 1200mm, 1350mm or full height, to the ceiling.
- Remove wet insulation.
- Surface and backing paper delamination may have occurred and should be inspected very carefullyand replaced if suspect.
- Stud adhesive may also have been compromised and may not become evident until later.
- Contamination of sheeting by sewage, toxins and chemicals needs to be evaluated.
Due to the greater risk to the integrity of plasterboard, almost all ceilings that have been inundated will need to be replaced (especially where absorbent insulation is involved). Water will likely have ponded for too long a period, and all the fixings compromised as well. If you see a sag in the ceiling from the ponding of water, cautiously, from the outer edge, working to the center, poke holes in the plasterboard using a broom handle or similar to slowly release the water. Saturated ceilings can be unsafe so be alert to any warning signs that it may collapse.
* Please note, the document primarily refers to Plasterboard. Fibre Cement Sheet is different to Plasterboard and subject to different considerations and might not require removal. Fibre Cement Sheet should be carefully assessed as to whether or not it contains any asbestos – seek specialist advice on removal if sheets contain asbestos. Please contact the fibre cement manufacturer for guidance.
The Removal of Affected Plasterboard
There are usually 2 main ways of doing this:
Remove the damaged sheets to approximately 300mm above the high water mark preferably at the nearest joint above the water line. Given sheets are either 1200 mm or 1350 mm high it will either be at these joints or at full wall height (see method 2 below).
Because the replacement joint will most likely be made up of one new recessed edge board abutting the existing sheet (a butt edge), the joint should be treated as a butt joint. There will be a crown created which may cause glancing light issues and setting out over 600mm (the same as a butt joint) will reduce the noticeability of the crown. See the Australian Standard AS/NZS 2589:2007 (Figure 4.4.5) for more information on setting out for butt joints. Note: A decorative dado rail may also be used over the new join without the requirement of trowelling.
Source: Australian Standards AS/NZS2589:2007
Fully remove the sheets to full wall height which will also involve the removal of the cornice.
This approach will usually necessitate the repainting of the ceiling unless a larger cornice can be applied over the area where the previous cornice was and there is no other damage evident.
- A qualified electrician is to be satisfied with wiring prior to sheeting.
- The framing must be dry (less than 16% moisture content) and the screws removed.
- Stud adhesive can be removed using a sharp chisel or more effectively, an electric planer, bearingin mind not to plane the studs.
- Any debris above the bottom plate to be removed.
- Water damaged insulation is not to be reused.
Wall and Ceiling Lining requires specific trade knowledge. For quality results use Qualified Wall and Ceiling contractors who are members of the AWCI.
For more detailed information and membership enquiries, please contact the AWCI on email@example.com or go to our website www.awci.org.au.
Manufacturers and Suppliers of Wall and Ceiling Linings have further specific information, please refer to their websites listed below.
USG Boral BGC
Please check the relevant State Government websites for valuable information and guides on disaster recovery.