Digging with high water table

[Tony L]

@Alan Ambrose you asked me to report back when we started to dig the trench foundations.

 

Just to recap, we have a high water table.  I did some research - it's usually at its lowest during the first week in October, so I booked the groundworks team.  Then we had the wettest September I can remember.  We dug some test holes a while back & the BCO came for a look & told us we'd need 1M deep trenches.  This is what had been specified on the new build right next door to us.  We were expecting to have to shutter the trenches to prevent them collapsing between the dig & the pour. A different BCO came to inspect the trenches once we'd started digging.  He told us he wanted to see 2M.  Due to the ground conditions, this work has been very much more difficult than digging 1M trenches.  As the pictures show, I don't have a nice, neat 60cm wide trench describing the outline of my house.  The reclaimed boards I'd collected to deal with the shuttering were deemed too weak to risk using for these ground conditions.  OSB (as they used next door) would also be too weak, so the pictures show lots of very expensive plywood, & 2 x 4 braces (these won't be left in).  The water you see in the pictures is being pumped - if the pump is off overnight, it's up over the boards the next day.  

[Tony L]

[ProDave]

We have a seasonal high water table, Mid summer perhaps June or July is the driest.  I would never have thought of digging in September let alone October.

 

We were about 1.5 metre without shuttering but needed a pump to keep the water out.  BCO inspection and pour same day.