Laying foundations in ground with a high water table

[Terry Hoy]

Please can anyone advise. I'm digging the ground to lay a foundation for a conservatory to the side of my bungalow. I've dug to a depth of 650mm and the trench is constantly being filled with water to a depth of about 100mm. The council made the builders of my bungalow put the their footings in very deep because of the high water table level, how deep I'm not sure, I havn't found the top of them yet. So how can I lay concrete foundations in these conditions? I have tried pumping out the water but it fills back quite quickly. Thanks in advance. Terry

[Stuart]

Is 650mm really deep enough?

If there is no way (and there usually is) of creating a dry trench to pour the concrete in, then special conretes are available that are designed to set under water!

[Terry Hoy]

On Sat, 24 Apr 2004 11:25:45 +0100, "Stuart" wrote: The good news is that having pumped the water out again the level is returning to a lower level, so I think that I will win the race. I had considered going down to a meter depth but this water problem would have made getting there a bit more difficult. Terry

[N. Thornton]

I thought any old concrete would set under water. I would assume continuous pumping would be the way, perhaps someone else knows another approach, but I cant imagine how else one would do it. I might dig a small hole in the bottom to sit the pump in, and whip it out the second before the concrete goes in.

Regards, NT

[Stuart]

Yes, any portland based concrete will, howevr the concretes designed for underwater use are better at it!

[The Natural Philosopher]

Easy. Fill the rench with concrete. The water will overflow and run away. The concrete will then set with a nice layer of water on top which will stop premeture drying.

Only the very top layer may not set so brush any loose dust off after it has all dried out.

[Michael Mcneil]

Couldn't a few piles be sunk into the earth as the only weight they will be taking is light panelling?

[IMM]

Is this just drainage and not a high water table? If only drainage, on the outside of the concrete you pour, dig further out and lay hardcore and maybe a French drain. This will keep the water away from your foundations.

[NALLA]

replying to Terry Hoy, NALLA wrote: use pile foundations,this will be better or use trash motors and quick setting cement

[Brian Gaff]

Worrying that somebody would use this usenet interface. Would you trust foundations laid by a user of this interface? Brian

[Andrew]

FFS, read the DATE of the post (2004).

if this house is in Suffolk or similar then it will now be part of the sea bed.