Making a home flood resistant

If you live in a flood risk area you should always have preparations ready in case of a flood. Preparing a plan for what you should do in the event of a flood is well worth the time it may take – it could save you a lot of money, inconvenience and stress.

Sandbags

It is a good idea to always have a supply of sandbags at hand if you live in a flood risk area. If you do not have sandbags you can use alternatives such as pillow cases or refuse sacks filled with garden soil. Remember not to fill them too early or far away from the site where you may need them as they can get very heavy, very quickly.

  • When filling a sandbag wear protective gloves as sand is abrasive.
  • Do not fill the bags more than half full. It is not necessary to tie the ends of the bags, simply tuck the open ends underneath when you are stacking them.
  • Remove any debris from the area where the bags are to be placed.
  • Place the half-filled bags length ways and parallel to the direction of the water flow.
  • Place bags in layers like a brick wall, make sure that in the next layer each bag overlaps the one below by half.
  • Stamp bags firmly into place to eliminate gaps and create a tight seal.
  • If you need sandbag protection which is more than three layers high, build them up in a pyramid style: begin with a base more than four sandbags thick and then build upwards, tapering towards the top.
  • For extra waterproofing cover your sandbag wall with plastic sheeting, making sure to weigh it down with additional sandbags on the ground.

Although sandbags are a popular defence against floods they do have their disadvantages:

  • During an emergency, sufficient quantities may be difficult to obtain.
  • They are time-consuming and require two people to fill.
  • They can be difficult to handle, particularly for the elderly or infirm.
  • When they come into contact with floodwater, they tend to retain contaminants such as sewage.
  • Sacking material is biodegradable and can disintegrate if left in place for long periods of time.
  • Sandbags are not 100% watertight and it may still be necessary to have measures in place for removing water behind them.

Floodboards

Floodboards (or flood barriers) are removable barriers that can be placed across openings, such as doors, in the event of a flood. There are a number of specifically designed, commercially available products that can be bought and fitted. If you buy floodboards, you should look for a product that has a quality assurance mark.

It is also possible to make your own floodboards, although care should be taken to make sure that the barrier is strong enough and that it fits properly in the opening for which it is intended to form a proper seal.

The easiest way to make floodboards is to construct a wooden or metal barrier that is secured flat against a wall, door or across gateways or paths by means of a frame. The pressure of the floodwater itself will help seal the barrier. The efficiency of the boards will be determined by the strength of the walls and the durability of the frame fittings. The most common type of flood board is one which can slide down into the frame, as this can be removed easily when not needed. But you can also make a hinged variety which can swing closed across any gaps. It is important that floodboards fit precisely. If in doubt it may be best to buy specialist items.

Wrapping

Wrapping is an advanced method of reducing the effects of floodwater by enclosing the bottom 600-900mm (2-3 feet) of a property in plastic sheeting.

The process involves digging a trench in front of the wall you wish to protect. The plastic sheeting is attached to the wall above the expected height of the floodwater. It is run down the wall and placed over a drainpipe at the base, before being run through the trench and secured on the other side with weights or sandbags. Wrapping a building takes some DIY ability and needs to be started well before any floodwater arrives as it does take some time. Alternatively there are commercially available products that can be bought and fitted to your property.

Flood protection products can be effective in mitigating against the adverse consequences for properties at risk of flooding.  They can reduce the damage caused to contents, furniture and fittings in a house or business, but are not applicable in all situations.  In cases of severe flooding (where floodwater rises above 1 metre), keeping water out of your property can be more harmful than letting it in. The stress on the building caused by that amount of water can damage the structure and foundations of the building. Therefore you should never block doors, windows or air-vents over 1 metre in height.

Property owners considering the use of such methods should seek the advice of an appropriately qualified expert on the suitability of measures for their property, and consider the possible requirements for environmental assessment.

Floodgates

These slide in front of entrances such as driveways and doors, to stop floodwater entering your property.

Air Vent Covers

Air vents or air bricks must be sealed during a Flood Risk Period. A number of types of temporary covers are available to seal these openings.

Barriers

These come in a variety of shapes and sizes, and can be used to prevent floodwater entering your property.