A CONTRACTOR’S GUIDE: TO REBUILDING AFTER A FLOOD

Steps To Restore A House Following Flood Damage.

The following are key steps for restoring a home after flooding damage:

* All villaboard services should be made safe, especially under kitchen and bathroom cabinets.

* If necessary, plasterboard linings should also be removed to allow drying to occur.

* Check for moisture content. No finishing work should take place until the moisture content of walls has fallen below 16.5%. Refer to the back of the booklet for the “Quick Guide”. This information is meant to be a guideline for contractors who work on flood-affected homes.

Introduction.

This guideline was created to assist with flood recovery. This guideline addresses immediate problems, long-term and mid-term restoration, and restoration.

The largest investment in a person’s life is a house. During the restoration and repair process, there is often an emotional attachment to the home. The immediate concerns of the homeowner are whether insurance covers the damage and whether they will be able to continue living in the house during the restoration process. This guideline is for restoration and repair only.

Urgent Issues

Before you begin the cleanup, make sure that there is no immediate danger to the property’s occupants. This means that the power supplier has cut off the power supply or verified that the installation and supply are safe. Individually, gas and electrical appliances, devices, and services must be checked and marked as safe or disabled. This will indicate that the sewage system is safe for workers and poses no risk to their health during cleaning.

It is a good idea, especially if the owner’s insurance company does not have the opportunity to inspect the area, to take photographs of any damage or items that are being removed.

Safety And Health

While restoration and repair work is being done, some houses can still be lived in. Some houses will remain vacant while the restoration and repair work is underway. This will make it possible to strip out, dry out, and restore without having to take into account the owner’s immediate needs. Before full restoration, some houses may need to be removed and made safe for use. The house can be lived in if:

* it is safe to live there

* the initial cleanup of water, mud, and debris has been completed

* the power supply has been restored safely

* all water sources and sewage systems have been tested and checked and repaired as necessary * some wall sheeting may need to be removed to allow for drying. It is important to remove nails and splinters from wall framing, make sure power outlets are safe, and ensure that any electrical wiring is securely clipped and certified by an electrician before allowing the house to be occupied.

Cleaning Up

All wet items (furniture and bedding, carpets, clothes, appliances, books, papers, etc.) should be taken outside to dry out. Items that are unable to be cleaned due to water contamination must be disposed of. This includes plasterboard, other wall linings, and glass fiber insulation. It may also include carpets, mattresses, lounge furniture, etc.

Nothing should be kept in the house that could trap moisture or slow down the drying process. To allow these damp and dark spaces to dry out, remove the plinths (kickers) from under the kitchen and bathroom cabinets. To access pockets of water and debris, you will need to:

* Remove all skirtings, cupboard kick panels, and front panel to baths;

* remove internal wall linings enough to allow for the cleaning of the external cavity. It is necessary to remove the plasterboard from the closest joint to the flood level (i.e., 1200mm, 1350mm, or full height).

* Drilling holes in ceilings or removing water logged ceilings.

* disconnecting power supply.

Use shovels or squeegees to remove mud and other debris.

If you have enough water, then use a hose that has moderate nozzle pressure to remove the dirt and mud. Start at the highest point of flooding and work your way down to the basement or floor. To flush out dirt, place the hose in any spaces that are not visible. To reduce flood-carried infections, the surfaces should be cleaned with a biocide disinfectant or diluted bleach. Because of the building paper and the need to replace insulation materials, it is easier to clean the exterior wall cavities from inside the house than the outside.

There is a possibility that silt could have built up between the exterior wall cladding of the building paper and flood waters. If this is the situation, the cladding must be removed enough to allow for the silt to be lifted. It will impact the performance of the paper. For timber-clad exteriors, removing or wedging out the bottom two to three weatherboards in the wall cavity will allow drainage and flushing of any silt that extends beyond the floor. This will allow for better ventilation and aid in drying. Sheet-clad houses may require the removal of all sheets.

Sub-Floor Spaces

To prevent moisture from lingering, it is important to dry out the area under the floor. Flood waters could have caused a change in the ground profile beneath a house, allowing water to pool. You can drain the water from the floor by:

* Digging drainage channels to drain it out

* Pumping water out

* Digging a pit to collect the water, and then pumping it out.

To prevent water from ponding beneath a house, it is important that the subfloor ground surfaces be higher than the ground around it. After the subfloor water has been a drained, it is time to remove any debris that has been left under the house. To prevent water ponding, sub-floor spaces should allow for drainage to the exterior. Sub-floor services like drains, pipes, and wiring should be checked and repaired. Floodwater can carry silt into the storm water and sewage drains through the gully traps. It may be necessary to flush the area with clean water. To dry the underfloor space, you should clear debris from the exterior of the building. 

Drying The House

After all wet materials have been removed, the house can be dried out. It is best to dry quickly. It is possible to speed up drying by removing linings. When the house is dry, internal linings can be easily replaced. You should not re-line a timber wall frame if the moisture content has fallen below 16%. To maximize ventilation and drying, it is a good idea to keep windows and doors wide open on dry days. It is possible for windows and doors to become difficult to open because they may have swelled from the water. Keep windows open on wet days to allow for ventilation. These items will dry faster if drawers and cupboard doors are left open. You can dry moisture using fans and heaters, but it is important to avoid heating too much as this can cause wood to split and warp. To remove warm moist air from a house, ventilation is important. A heat gun or light sanding can help dry a suspended timber floor.

* ensuring good ventilation inside and out

* lifting waterproof floor coverings such as vinyl sheets, vinyl tiles, or ceramic tiles. You should not attempt to straighten a damaged or buckled timber floor until the entire house has dried and the moisture content is below 16%.

Interior walls

You can scrub hard linings such as wood paneling and villaboard with a stiff bristle toothbrush using lots of water and detergent to remove dirt from cracks and corners. You should rinse the surfaces with cold, clean water. Plasterboard has a low tolerance for water. It will need to be removed and replaced when it becomes damaged or delaminated. Plasterboard should be removed from the closest joint above the inundation point. These will be at full height, 1200mm, or 1350mm. Composite wood materials such as MDF (Medium Density Fiberboard) and particleboard are less tolerant to water immersion than other materials. They will need to be replaced. This includes doors, skirtings, and architraves, as well as window reveal, jamb lines, and joinery units like kitchen cabinets, vanity units, and wardrobes.

Doors, Cabinets

Doors and cabinets are usually made of timber-based products. After being inundated, they will swell and become unusable. Many cabinets are made from plywood or particleboard, which can delaminate and become disintegrated over time. Cabinets and doors that have been submerged even partially will need to be repaired. Water “wicking” through the end grain can cause veneered doors to delaminate or be damaged. Wood panels or solid wood doors can also swell and then shrink, which could cause cracks and open joints. All doors and cabinets that are partially or fully submerged in water will need to be replaced.

Exterior Walls

Many houses are made of brick, brick veneer, or solid blockwork. To aid in the drying out of the wall cavity, weep holes must be removed. After drying out, renders and other applied finishes should be carefully examined to determine if there has been any delamination. If it has, it should be removed and replaced. All perimeter vents should be opened for houses with elevated floors to allow as much cross-ventilation as possible and air movement in the crawl space. To minimize moisture damage, it is important to dry the floor joists, floor sheets, or floorboards completely from the underside.

Electrical And Appliance

The electric motors of most appliances are mounted low to the ground. This can cause damage to bearings and motors. After testing and inspection by an electrician or mechanical contractor, these should be replaced if necessary. 

Repairs

Owners want their houses to be restored to their original condition as quickly as possible. However, it is important that the house is adequately dry before any repairs are made. It is possible to cause damage to the structure or finishes if the house has not dried properly. In-service moisture content for timber in houses is usually between 9% to 13%.

The timber absorbs moisture from water, and it will take some time before the moisture content returns to its original level. Before wall linings are replaced, they must be below 16%. It is possible that damaged building paper will need to be replaced. The damaged areas of cladding will need to be removed from the exterior of the house. It is not enough to attach a new piece of cladding between the studs.

All work done to reinstate a structure must comply with the Building Code. If possible, tie-down straps should be added between the bottom plates and studs. Also, check the number of foundation bolts to ensure they are adequate. Use a straight edge to check for swelling on particleboard floors. The floor should be flatly sanded if it has more than 4mm of swelling.

Replace the floor if it is more than 6-8mm. Doors (including cupboard doors) that have been damaged by swelling, blistering, or peeling surfaces should be replaced. Sometimes, existing frames can be kept. After the house has been cleaned and dried, the following items can then be reinstalled:

* appliances

* hot cylinders

* air conditioner condensers

* central heating and vacuum systems

* toilet mixers

* and electrical fittings.

* carpet that does not have rubber backing (rubber underlay) will limit the final drying.

You should not paint until the humidity levels are below 16%. If ventilation holes in foundation walls have been damaged or removed, they should be vermin-proofed to aid drying.

Testing For Moisture

A moisture meter should first be used before any wall linings can be replaced. This will determine if the framing moisture level is at an acceptable level. Plasterboard fixers must ensure that moisture levels meet the standards of the product manufacturer.

A flooring hygrometer is the best way to determine concrete floor dryness. The following methods will provide a general indication as to the level of moisture if one is unavailable.

Tape the four edges of a 1mx1m clear polyethylene sheet to a floor area that is not in direct sunlight. Cover the area with a blanket, and let it dry for 24 hours. Condensation may form on the floor’s underside. This indicates that the floor is not suitable for vinyl or carpet with rubber backing or underlay. If the floor is too damp, lift the polyethylene. Do not leave the taped piece on the floor. Before you lay the floor covering, wait until the polyethylene taped in is dry.