Flood Prevention Measures
It is possible to either assess the risk yourself or engage a risk assessment consultant to do it on your behalf to find out which strategy you will need to implement for flood prevention. There are four main groups:
- Very low risk, no flood prevention required.
- Low risk of river, seawater or flash floods but a risk of basement/cellar ingress from rising groundwater.
- Requirement to prevent normal flood levels from entering a single property.
- Requirement to prevent normal flood levels from entering an area or several properties.
It should be said that if flooding reaches over a metre in depth it will certainly cause structural damage to most buildings if kept out. This is because of the enormous weight differential between the outside and inside of the walls, so less damage will be caused overall if flooding at this depth is actually allowed inside the building.
How water enters a property
There are two main points of entry for water; above ground and below ground.
Above ground water can ingress through:
- doors and windows - look for gaps and cracks in joint sealant
- gaps around pipes, cables and other services that pass through the walls
- vents from boilers, washing machines and tumble dryers
- cracked or damaged mortar or cracks in the brickwork
- permeable stone, block or brick walls
- party walls
- at the damp proof course
Below ground water comes through:
- blocked drains or sewers which can backflow into a property
- rising groundwater can flood a basement/cellar that is not tanked effectively,
- cracks in solid floors
- the space below suspended floors
Featured Company - Floodplan
One of the most effective methods to protect your home from severe flooding is to install flood boards or flood barriers. Floodplan has developed an effective flood protection system which offers a full guarantee and complete customer confidence in the reliability of their products.
Once the installation is complete it is very easy to respond to flood warnings by placing the barriers in front of your doors.
The barriers are very easy to set up once the initial installation is complete, taking a matter of only 30 seconds! The company also supply air vents covers to seal other areas of potential water ingress around your home.
Floodplan offers a cost effective and highly knowledgeable service to help you secure you home from flooding. Call 01260 289089 or email email@example.com
Keeping a single property dry
This is probably the most satisfactory solution for most home owners. A dry home can be achieved relatively economically and will avoid damage to furnishings, furniture and possessions as well as minimising the stress that flooding causes. However, flooding will still cause damage to your garden; any outside structures such as garages or sheds and your car may still be at risk.
Once you have surveyed the property take the following actions:
- Repair any weak or broken brickwork or mortar
- Consider replacing your doors or windows with flood resistant doors or flood resistant windows
- Seal gaps around services that pass through the walls
- Install a Sump and Pump Systems if required. See above for details.
- If you are in a semi-detached or terraced house, check with your neighbours what measures they intend to take.
Each property will require a different portfolio of measures, typically:
- A supply of sandbags or custom made removable barriers to block doors, windows and patio doors. Note that although many local authorities and emergency services have a stock of sandbags; when a flood arrives they are unlikely to be available to individual homes or businesses as priority is given to hospitals, nursing homes and other vulnerable groups.
- Purchase drainage plugs and covers that can be fitted once a flood warning has been issued or fit permanent non return valves to drains that will prevent backflow and the extremely unpleasant prospect of sewage entering your property.
- Protect airbricks and vents with covers. Some can be fitted permanently and will close in the event of a flood. Other types are clipped in place once a flood warning is issued.
- For commercial premises at risk consider installing commercial flood proof doors and windows or installing permanent flood barriers that can be operated hydraulically to seal off large door spaces.
See also: You have been flooded
Tanking Systems provide a waterproof lining for a basement or cellar by covering the inside walls with a coating or membrane bonded to the structure. The treatment should be guaranteed to withstand the expected head of water, typically 5 metres or more that will cater for the height of the basement and the expected above-ground floodwater.
Sump and Pump Systems can be operated at basement and ground floor levels. They work by providing a sump (a lined hole 60cm in diameter and deep enough to provide sufficient capacity) into which rising groundwater or floodwater will flow and a pump is installed to remove it outside of the building. The most important factor is sizing your system correctly to cope with the anticipated load. A 1 kW pump is adequate for most homes but bear in mind that the electricity supply to drive the pump may be cut off in a flood so consider a battery or solar driven pump as a back-up measure.
Area or multiple property protection
Larger areas or multiple properties can be protected by permanent or removable barriers or portable dams. They avoid the need to do work to your property and are available as:
- Barriers that are installed into prepared fittings in embankments or riversides
- Portable coffer dams
- Plastic membranes that can be deployed around a property
- Permanently installed and hydraulically deployed barriers
- Pallet barriers
- See our Supplier Pages for links to suppliers of Removable Barriers, Permanently Installed Flood Barriers and Portable Dams.