First noticed this problem end of June following the very heavy rain. At that point we didnt notice till it was 3 inches deep throughout the ground floor of the house. It drained away by itself by the end of the day.
It returned again following the recent flooding in Gloucestershire and was double the depth once discovered and still rising - at that point we started to bail the water out of the void to prevent ingress through the actual floorboards. Eventually we pumped all the water out.
We now have some floorboards up in all the affected rooms (we have an extension on the side of the house with a concrete sub floor which was unaffected) so as to dry out the void.
However yesterday we had another couple of heavy downpours and the water entered again - nothing on the scale previously but we have now discovered its entry point - through the base of the bay window in the lounge.
Please can anyone offer me suggestions as to where I go from here. Have had a couple of different solutions but would appreciate more.
Digging a 3 foot trent across the front of the property to create a land-drain which will T off into the front lawn and enter a soak away, wait to see if that solves the problem - or put down concrete floors as well with relevant membrane, insulation, concrete and 3" screed. The void by the way is 12" deep. The other option offered is to tank the void and then put in a membrane, insulation and top up with concrete - this builder feels that land drain is not necessary.
Confused & frustrated - please help.