Begining to dry out after the floods and am looking to build a wooden flood barrier in my back garden to prevent water coming accross it towards my house .This has only happened twice in twenty years and this year was the worst rain for 100 years and the water subsides quickly so not going to have to hold it back for weeks for example. My plan would be 4 inch square 6ft posts which would be 3ft in ground with concrete and 3ft out .These would be 7ft apart with beams 14ft long 8inch deep and 3 inch thick.All would be treated wood and depending on cost would prefer hard wood.Questions are please-
Anybody got any idea how long I could expect this to last if maintained?
Anyone got the same and could advise ?
Any advice re pitfalls ?
Also got a water pump and saving for bigger one following advice from guys previously so prepping coming together .(Not getting caught out like that again)
Cheers
DT
If you are only using 4 inch square posts I would triangulate off the back as well personally
I think I would use either 6 or 8 inch if I could get them and probably still triangulate off those with 4 inch
Each 1000 litres of water 3 ft x 3 ft x 3 ft is around a ton in weight so there is with what behind it going to be a fair force on your 3 ft height and 7 ft width between posts
Only other thing I would add would be a large stash of sandbags covered on a pallet
As above, 4" posts are unlikely to be man enough for what you want.
But also any barrier that you erect will be pointless unless you first have a means of sealing off "ALL" of the drains and sewers etc that connect to your garden and house etc.
Also the planks that you are going to fit between the posts, what are you going to do to seal the gaps between the individual planks?? Professional systems would use a tongue and grove type of system with rubber seals, you could alternatively wrap the entire barrier with a sheet of visqueen, but this all takes time which you may not have.
If it was me, I would look at building something more permanent such as a blockwork wall with a waterproof render, then all you need to do is erect a barrier over any gateways and here you could have preformed slots into which you simply slide in a pre-made barrier/floodgate - however, the point about the drains above still stands!
It's hard to advise without seeing what you're working with, maybe a sketch of your house boundary, with water courses, drains, usual flood points and high/low points would help?
I live near Mytholmroyd which was really bad earlier this year, we drove through a few days later and a few residents had tried to erect barriers, but all it did was move where the water got in, water will find it's way through granite over time, but if in your case, the water comes and goes pretty quickly, then you might be ok just moving it along to buy time.
I would go with H section RSJ's with used British wooden sleepers slotted between them - the ones that are sat in creosote for a couple of years before use! However sleepers are not light, they would be a 2 man lift minimum and assembly wouldn't be quick
If guns are outlawed then only the outlaws will have guns....
One thought, if you builds barrier across your garden what happens to the water that goes round it?
You could have a couple of issues:
1. Diverting water onto someone else land could cause them problems and then they come knocking on your door
2. Water goes round the ends and still affects you
Not knowing the geography of what your dealing with, I could be wrong
How deep is the water lightly to be on the barrier? As mentioned already water is very heavy. Are you planning on it being permenent or a removable barrier, and is it spanning a gap in say walls or does it need to be three sides (or all four) ?
I would suggest you consult an structural engineer, if your barrier fails suddenly it might be a lot worse than just having it flood naturally, they also pick up on stuff you or I might not know about, things like ground seepage and load factors.
In your place I'd be looking at a solid wall, probably backed by an earth bank, but I'm just guessing without knowing the layout.
Hi all ,thankyou for all the feedback and all helpful.The point I will put the barrier has only ever had flood water twice in twenty years.This was the worst went from 18 inches down to about 6inches near the house .So thinking that will make the barrier 30-36 inches above ground.From the feedback before buying wood I will look at sandstone blocks and if to dear and need to use wood then -
Will use sleepers for the posts and sleepers for the barrier as they are long.(concrete three feet deep)
Will use the angle supports but use concrete for them to hold against.
The depth will not affect others land and will use rubber between the sleepers to stop leaks.
Have already sandbags away in the garage and the ones lying out need a tarp to cover but doing that this weekend.
