Preparing for flooding

[adam2]

Thought others might be interested to know of preps made by a friend who lives in an area prone to flooding.
Moving from the area was considered and then rejected as too expensive, they have therefore decided to stay in the district and ensure that they will not only survive a bad flood, but also suffer minimum financial loss.

Following the last flood, they purchased, very cheaply, a flood damaged house near theire original home.
The following work was done to make the house flood tolerant.

The downstairs wooden floors had rotted due to past floods, replaced with concrete, well insulated and with wet type underfloor heating.

A non load bearing internal wall was replaced with masonry, both to increase thermal mass, and to better support the floor above and allow all manner of heavy items to be stored above.
This upper floor was renewed, with joists at half the usuall spacing, in order that the floor can support 10 tonnes with an ample safety margin.
This room contains batteries, bottled water, tinned food, candles, a spare woodstove, and all the other heavy supplies.

The house was re wired throughout, with all downstairs socket outlets 2M above floor level, and all lightswitches ceiling mounted and cord operated, fuse box and meter at high level.
A small 12 volt PV powered lighting system was installed, the batteries and controls being upstairs of course.

The food preparation area was placed upstairs since cooking and laundry appliances are expensive to replace after water damage.
Although the main living room is downstairs, the most expensive contents are TV/Hi Fi/IT equipment, this is located above the 50 year flood level, and can be taken upstairs if worse flooding is expected.

Main heating is by a gas boiler, heating radiators upstairs and underfloor heating downstairs. The boiler, pump and controls are upstairs.
Secondary heating is by a very cheap woodstove, at less than £60, replacement after a flood is viable, though it might survive OK

Downstairs floor covering is a mixture of ceramic tiles (only need pressure washing and disinfecting after a flood) and carpet tiles that are very cheap to replace.

Downstairs walls were stripped back to bare bricks, and left thus if attractive, and painted with exterior paint otherwise, would only need pressure washing and disinfecting after the flood.

A door has been installed opening from the upstairs landing onto the flat garage roof, to permit access via a boat if required.
The garage roof was strengthened in order that several persons could stand there, together with a generator.
A large water tank, filled by rain from the house roof, is placed on the garage roof, this is normally used to water the garden but could be used for drinking if suitably treated.
A strong concrete coal bunker is placed next to the garage, in order that persons may board a boat from this, if the water is too deep for wading, but not deep enough to reach near the garage roof. (these arrangements would provide handy access for thieves, therefore the door is a thief resistant type with good locks)

All downstairs doors and windows are UPVC and thief resistant with good locks.
The main bathroom is upstairs with a second WC downstairs, which is equiped with an anti backflow valve to prevent sewage/floodwater entering via the soil pipe.

To facilitate prompt repairs and drying out after a flood, the store room also contains a couple of industrial dehumidifiers, spare carpet tiles, paint, tools, together with spare parts for almost everything (though that is more in case of general disaster rather than flooding)

All this entailed very considerable expense, but has resulted in a house much larger and better equiped than could have been afforded otherwise, and in the right location for schools and work.
Many of the preps are of course useful for other problems as well.

The only thing that cant be saved is the car (unless time permits of driving it to high ground) It however is worth less than £2,000, and wont be replaced with anything worth more.

[Adam1]

Is it also not worth getting this sort of thing?

http://www.floodcontrol.co.uk/flood-barrier.htm

[adam2]

Is it also not worth getting this sort of thing?

http://www.floodcontrol.co.uk/flood-barrier.htm

If only relativly minor flooding is expected, such defences can be very valuable, however they are of limited use against water more than about 1M deep.
Although the barriers can be made much more than a metre high, remember that floodwater on only the outside of the building will apply considerable sidewards pressure on the walls. Unless of greater than normal strength, the walls will be liable to collapse with more than about a metre difference in external and internal water levels.

Also any such structure is unlikely to be completly water tight, in all but very short term floods, the internal water level would soon approach the external level. The water that gets in around or under the barrier can of course be pumped out, but this will require an engine driven pump (preferably in duplicate in case of failure) and ample petrol/diesel.

[DominicJ]

Can the upstairs heating be isolated?
Might be worth looking into, if it does flood, the under floor heating will be trying to heat a river, and your(his) boiler just wont stand a chance

[adam2]

Can the upstairs heating be isolated?
Might be worth looking into, if it does flood, the under floor heating will be trying to heat a river, and your(his) boiler just wont stand a chance

No such facility was installed, it would be simple to add though, and I will suggest it.

[Andy Hunt]

A really interesting post adam2, thanks for posting.

Was any consideration given to the location of toilets (i.e. upstairs to prevent sewage backflow into the house)?

[2 As and a B]

Interesting. Our house has an integral garage so the upstairs is bigger than the ground floor. However we are nowhere near a flooding danger.

One thought occurred to me. If the food preparation room is upstairs, where do they eat?

[Mark]

The National Flood Forum is a good source of info on flooding matters:
http://www.floodforum.org.uk/
They have put together a "Blue Pages" which is a directory of flood protection products and services.
It gives details of what a product does, where it can be obtained and contact/web site details:
http://www.floodforum.org.uk/folder.200 ... h%2009.pdf

Also, IEMA are running an event for businesses on 18th June called 'Flooding, Vulnerability & Resistance' in Manchester:
https://www.iema.net/?module=ievents&fu ... 10&eid=893

[adam2]

Interesting. Our house has an integral garage so the upstairs is bigger than the ground floor. However we are nowhere near a flooding danger.

One thought occurred to me. If the kitchen is upstairs, where do they eat?

Snacks and quick meals are eaten where prepared, main meals normally downstairs, especialy if watching TV at the same time.

[adam2]

Update to this old thread.
They have just had a flood, about 600mm of water downstairs which has now drained way.
A cheap carpet and a cheap sofa are the only items needing replacement, the flood occured at night or the carpet could have been saved, but the sofa wont go up the stairs.
A PC was lost by being dropped down the stairs.

Cleaning up underway, expense about £2,000 including the PC which was only indirectly lost by the flood.
Carpet tiles also need replacing, but these cost nothing from office refurbs.

[biffvernon]

Well done that man. Shame about dropping the pc!

Next month our local authority, police, fire etc are organizing a big exercise involving evacuating 150 people from one of the coastal villages, moving them inland, giving them lunch and taking them home again. I've volunteered. (Well, there's a free lunch in it.)

[adam2]

Update time.

They have recently been flooded, several times only slightly but the worst was nearly 1M deep.
All electronic goods taken upstairs in case the water got deeper, theough they would have just survived if left in situ.
Carpet all thrown out, but replacement carpet tiles cost nothing from office refurbs.
Cheap sofa destroyed, other downstairs furniture either taken upstairs or saved by being placed atop the sofa.
No damage to electrical installation as it is all at high level.

Downstairs all pressure washed and disinfected as the floodwater probably contained sewage.

The only other loss was the fire wood, which all floated away.
The coal was soaked but should be fine when dried.

In case of severe flooding they have a boat, but conditions were not so bad as to need it.
An inflatable was rejected due to the risk of puncture on sharp debris.
A wooden boat needs a lot of TLC especialy if stored in the open.
They therefore selected a rigid hulled aluminium boat, this has a double skinned hull with rigid foam between. The bouyancy of the foam renders the boat unsinkable, even if holed or swamped it will still float, though much lower in the water.

[ujoni08]

Very interesting, and thanks for the update.
Something to think about more if we get big rises in the sea level.

[JavaScriptDonkey]

I wonder what structural damage is being caused by regularly swamping the soil surrounding the foundations?

I also wonder how they are cleaning out the foul water left between the walls.

[adam2]

I wonder what structural damage is being caused by regularly swamping the soil surrounding the foundations?

I also wonder how they are cleaning out the foul water left between the walls.

It is a fairly damp and low lying area in any case, and I doubt that water 1M above the ground for a day or two every few years, or just above the ground for a few days a year, has a much different effect to that of the normaly high water table.

The walls are solid.

They have insurance against most perils, EXCEPT for flood damage to contents, fixtures and fittings.
Fire and theft are covered, as is damage to the structure from flooding, but NOT non structural flood damage.