Mary Dhonau Associates

How Do I Protect My Home From Flooding?

How Do I Protect My Home From Flooding? The big question many families have to ask themselves. Some people prefer to try to keep the water way from their homes. Self rising flood barriers are a good option – it uses the water to activate closure. As does Watergate, which pictured below following a successful deployment. Also Flood stop  has proved successful, especially in surface water flooding.

Five million people live with the threat of being flooded from the river and sea and 200,000 of those are considered to be at very high risk. In addition, as yet there is no definitive number for those who are at risk of flooding from urban drainage. Bearing in mind that approximately two thirds of the insurance claims from the catastrophic floods of summer of 2007 were from this form of flooding, it’s no wonder the insurance industry is jittery about the amount they have to pay out for flood damage.

This gloomy scenario threatens to become even worse with the effects of climate change and the pressure to build new homes.


Preparation is essential!

One way of avoiding being flooded is to check if your home is at risk of flooding before you consider buying it. Go to the Environment Agency’s website at  and check there if your proposed property is deemed at risk of being flooded. In addition, there are many companies, such as Landmark Home Check which for just a few pounds will give you details of all forms of flood risk including surface water (pluvial) flooding (flooding caused by excessive rainfall and as a consequence the drains just not being able to cope.) If you are already living in a house deemed at risk of being flooded, apart from moving or having flood defences, your only alternative is to plan and prepare for the threat of being flooded.


But it is not all doom and gloom! Home owners and businesses can put in protection measures that will help to minimise the damage and speed up the repair time. This is known as ‘Flood Resistance’ ~ this means protecting  a property, using flood protection products or building materials to try to prevent floodwater from entering a property and damaging its fabric and contents. (Or, in the worst case scenario, they will at least give homeowners time to move their possessions to a safe place.)


These measures will involve some expense but will pay for themselves in the long term and will represent time and money well spent  and, hopefully, reduce the distress flooding causes. They are far superior to the humble and inefficient traditional sandbags which often only filter the water. This type of intervention is only applicable if the flood water is no more than 0.9 of a metre deep (.6 in a new property) and if the floodwater does not lurk about for too long, e.g. a flashy type flood such as we experience as a result of a heavy downpour, following an intensive localised rainstorm, or in an area where a river rises and falls very swiftly.

A first port of call, of course, is to sign up to the Environment Agency’s flood warning system. Telephone Floodline on 0845 988  1188. If your area, or type of flooding is not covered by a flood warning, then invest in a ‘flood alarm’ There are quite a few types on the market varying in their level of sophistication.

Photo:  A flood alarm and a telemetry system ( the latter can ring up many people to alert that a flash flood is imminent.)


The Environment Agency has tested some flood protection products for reliability and these have been given a ‘kite mark,’ details of these products can be found on the Environment Agency’s website


The Property Care Association has a list of reputable flood protection firms on their website.  In addition,  the Know Your Flood Risk campaign has a comprehensive guide called ‘the Home-owners guide to Flood Resilience’, .It  can be found by visiting


Protecting airbricks

I spoke with many people after the floods of 2007 and I was often told that the flood water entered their homes only though their airbricks. This type of flooding is easily preventable. There are quite a few different varieties of airbrick protection.

  • An ‘elastoplast’ type~ one use only ‘stick on’ variety.( Good to have for peace of mind if you live in a low risk flood area)
  • Covers that can be screwed into the holes.
  • Some that have a fixture permanently on the wall so that, once you have a flood warning, you can easily clip the protection cover in place.
  • Relatively new on the market a ‘fit and forget’ air brick replacement, which basically is self activating and gives the homeowner peace of mind in that the airbrick will be protected should a flood occur when they are away from their home.



Protecting doorways

Floodwater can often enter a home via the doorway sometimes entering a home through the front door and leaving via the back door destroying everything en route. This type of flooding could well be prevented, or at the very least lessened, by fitting doorway flood protection. This can be easily fitted in front of your doors, should you receive a flood warning or else think a flash flood might be likely when a  heavy thunderstorm is forecast. Also think about keeping a supply of ‘sandless sandbags’~ they are a bit like disposable nappies for giants and can soak up to about 20 litres of water.( These can mop up any residue.) You can also replace your existing door with what effectively looks like a ‘normal’ door but has built in flood protection. ( pictured) This type of door will save you having to fit  the  flood protection during the night, if you get a flood warning. ( Flood warning do have a habit of arriving during the hours of darkness!) They will also always be in place when you are at work or on holiday. In addition, the insurance industry do prefer this type of protection, as it removes the need for human intervention!

The photos below show various kite marked flood doors working in anger and a ‘passive front door’


Other types of resistance products

Floodwater can enter your home or business in many ways, and not only through the front door and airbricks. Many people report that the first thing that alerted them to the fact that they were flooding is when their carpets became saturated. In this situation using a pump in a sump under the floor could help to keep the water level down. It is sensible to get the advice of an expert qualified in flood risk to help you make informed decisions before selecting such products. Anti back flow valves are very useful to stop sewage entering your home via the toilet. Failing that consider investing in a ‘toilet bung’ which can be easily fitted to stop the floodwater over topping the toilet. Floodwater will find the easiest point of entry, even via your washing machine or similar outlets. Again, you can purchase quite cheap anti backflow valves for these items. Also think about the condition of your external brick work, as floodwater will find the easiest port of entry. So have a good look at the outside of your property and repair any suspect mortar and cracked bricks. Also on the market are sealants which will make the brickwork more resilient to leaking but, at the same time, will allow the bricks to breath. Pictured below are Hydrosacks and Hydro Snakes ( one version of other similar intervention on the market) which are a useful addition to try to combat surface water flooding and also to supplement other forms of household flood mitigation.



A second option is to make your home ‘flood resilient’ – With means: Adapting a property to minimise the effect of floodwater, so that no permanent damage is caused and the structural integrity is maintained. Thus reducing the amount of time homeowners are out of their properties and the amount of money your insurance firm will have to pay out, helping you to be able to maintain your insurance cover. It is my view that, sadly, every flood defence will be over topped one day and that flood resilience is going to be the only sensible option when we adapt to living with the increased threat of flooding.


If a home owner is putting in resilience measures as part of the repair work after a flood, some changes would cost little more than putting it back to how it was before.


Examples of flood resilience include putting the plug sockets, boilers and service meters higher up the walls – above previous flood levels, installing tiled floors over a concrete floor, fitting plastic skirting boards, or using wood such as oak which is more resilient to floodwater. I used normal skirting board, but coated it with several layers of yacht varnish, when I was flooded again in 2007 and my skirting boards were fine! Replace your kitchen units with stainless steel, plastic carcasses (on which ‘normal’ doors can be fitted and removed before a flood) or else use solid wood rather than MDF or chipboard units (as these disintegrate with the effects of floodwater.)

Failing this, raise the units so flood water can run beneath them into a drain.





Replace ordinary plaster with lime-based plaster or cement render. Fit lightweight internal doors with rising hinges, so if you get a flood warning you can lift the doors off and out of harm’s way. Also, keep items of sentimental value upstairs where the floodwater can’t reach them. For more details see ‘how to restore your home following a flood,’ a publication written by the Association of British Insurers, which is available on their website .


In December 2006 the Labour government brought out new planning guidelines for future development (PPS25). This has now been updated by the government. ( Planning policy framework – details under useful links) With the threat of global warming and the pressure to build more and more houses, developers have now got to plan for the future and build-in flood resilience before the onset of any future flooding.PPS25 and subsequent guidance will help developers shape the way new homes are built in the future.


Statistics show that more people are at risk of being flooded than being burgled or seeing their house catching fire. Yet although people are prepared to protect themselves from burglary or fire, few actually take steps to cut down the effect that flooding will have on their homes, businesses and the devastation it brings to their lives. However, with the threat of increased flooding and the insurance industry breathing down our necks, we will soon be faced with no alternative but to do so!


Disclaimer: Before following any of my advice always seek advice from a qualified flood risk surveyor.
Whilst I have given various examples of flood mitigation products to enable you to see what can be done to reduce their own flood risk. I do not endorse any product.