nigel lewis wrote:
Over the past few months I have noticed water (2" deep)in the ground floor
void (approx 2'- 2 1/2'deep). I have checked all the main drains as it only
occurs during heavy rainfall. The water table is relatively high for this
area. I have considered filling the ground floor voids to either just below
the existing wooden floor joists or to complete the concrete screed at the
existing floor level. The fill would consist of hard core, sand blinding,
dpm, insulation, and concrete, floor joists and boards above. Concrete
screed to top that if I decide on finishing at floor level(within joists and
boards).

Anyone got any suggestions/advice?

Whatever you do, don't do that.

I had similar here, till I pulled the ruddy place down. There was a
small lake under the living room. The more rubble there was under the
house, the more it sucked up water and the easier it was to get into the
massive chimneys and rot any timbers anywhere near them.

What you need to do, apart from ripping up the ghastly wood floors and
laying a solid floor on top of a DPM having first put DPM of some sort
onto any walls..a BIG job..and then you might have to underpin as the
soil humidity will probably change and smash the (minimal) foundations
to pieces..

....is to dig a bloody great moat around the house, called a French
Drain, and fill it with a perforated pipe, and some shingle, and find a
lower part of the world to lead a 4" pipe to. In our case a nice
fishpond ;-)

This essentially acts as a drain for water trying to run under the house
in heavy weather..and since the house has a roof, the only other way in,
is via the water table, and, if you do that drain right, it will lower
that by a couple of feet naturally.

If you are on flat land, a soakaway may work..these can absorb temporary
high rainfall levels by lowering the actual water table locally in drier
spells.

If things are really bad and none of these solutions work, digging a
sump and putting in a pump and a float switch is not unusual.