Following a flood, be prepared to make difficult decisions about what to keep and what to throw out. Household items that have been contaminated by sewage or that have been wet for a long time, will have to be bagged, tagged, and discarded according to local bylaws.

Prior to conducting an assessment of potential flood damage in your home, it is important to assemble the equipment and supplies:

• Gloves, masks (N95 respirators), and other protective gear
• Pails, mops, squeegees, plastic garbage bags, and unscented detergent
• Large containers for wet bedding and clothing, and lines to hang them to dry
• You may also need to rent extension cords, submersible pumps, wet/dry shop vacuums, and humidifiers or heaters

Where there is extensive flood damage or if flood waters show evidence of being heavily contaminated by sewage, it may be necessary to do a more extensive cleanup in the home (carpets, crawl spaces, heating ducts). If you have extensive water damage or a wide spread mould problem develops, professional assistance should be obtained. Remember to contact your insurance agent immediately.

In situations with a small amount of flood damage with no indication of sewage contamination of flood waters, the Canada Mortgage and Housing Corporation recommends four steps for flood cleanup.

When cleaning after a flood, remember to:

• Store valuable papers that have been damaged in a freezer until you have time to work on them.
• Remove all soaked and dirty materials and debris, including wet insulation and drywall, residual mud and soil, furniture, appliances, clothing, and bedding.
• Hose down any dirt sticking to walls and furnishings, then rinse several times, removing the remaining water with a wet/dry shop vacuum. Rinse, then clean all floors as quickly as possible. Flooring that has been deeply penetrated by flood water or sewage should be discarded.
• Work from the top down. Break out all ceilings and walls that have been soaked or that have absorbed water. Remove materials at least 500 mm (20 in.) above the high-water line. Removing only the lower part of the wall applies if action is taken immediately after the flood or wetting event. Gypsum board walls that have been exposed to high humidity or standing water for a prolonged period of time should be removed in their entirety and discarded. Ceiling tiles and panelling should be treated like drywall.
• Wash and wipe/scrub down all affected or flooded surfaces with unscented detergent and water. Rinse. Repeat the process as needed. Concrete surfaces can be cleaned with a solution of TSP (tri-sodium phosphate) in water (one half cup of TSP to one gallon of warm water). When using TSP, which is highly corrosive, wear gloves and eye protection.
• Surfaces that are dry and/or have not been directly affected by the flood water should be vacuumed with a HEPA vacuum cleaner. Further cleaning of concrete surfaces can be done with TSP. Washable surfaces can be washed with unscented detergent and water. Surface mould on wood can be removed with a vacuum-sander. Do not sand without simultaneous vacuuming. Wood that looks mouldy after sanding may need to be replaced.
• After cleaning the surfaces, ventilate or dehumidify the house until it is completely dry. Rapid drying is important to prevent mould growth. When the outside weather permits (low humidity and moderate temperature), open doors and windows and hasten the drying process with fans. If the outside weather is not suitable and you notice that drying is not happening fast, use dehumidifying equipment, renting extra units as necessary.

To determine if the outdoor air can help dry the air inside, place a hygrometer in the area to be dried. Let it stabilize then open a window and monitor the Relative Humidity (RH). If it goes down then it means the air is dry enough to assist the drying process. If the RH increases, close the window.

• Carpets must be dried within two days. Sewage-soaked carpets must be discarded.
• Where large areas of soaked carpets cannot be dried using fans alone, a qualified professional is required.
• Ensure that all interior cavities and structural members are completely dry before closing cavities. Note: This could take weeks.