Damp issue

[Montana3827]

My husband and I are renovating a 1930’s house that we recently purchased. After removing the floorboards from the suspended floor we discovered there are damp patches in the ground underneath (please see photos included). There are no visible leaks and it has not rained recently. It appears to be coming up from the rear of the property. We’ve just had the drains checked and it was determined they are working properly. The underfloor is clean, air bricks are clear and well-ventilated. The damp doesn’t seem to go past the DPC as the bricks above it are all dry. My question is, is this something to be concerned about and does anyone have an idea what the cause of this could be? We are planning on insulating between the joists under the finished floor and want to get this issue dealt with (if intervention is necessary) before installing it. Any input is appreciated.

 

[Water Sourcer]

Hello Montana3827,
Natural water flows can move with time. Would you like me to see if I can detect a natural issue of this sort or possibly a leak? I will need a Google Earth photo of the property with map reference to match it up on my big screen.
Water Sourcer.