Rising damp guide
High Ground Levels and Damp Walls
A wall that became damp after a patio, driveway or garden alteration deserves a very close look outside. The timing may be more useful than the appearance of the internal stain.
How levels change over time
New paving is often laid over old paving. Gardens are raised, borders are filled and driveways resurfaced. Over decades the outside level can creep upwards until the lower brickwork and DPC are partly buried.
What to look for
Try to identify the DPC and measure its relationship to the finished ground. Also look for render dipping into soil, blocked vents and places where water ponds against the wall.
Why injection may miss the point
If water is entering the wall above the existing barrier, adding another chemical barrier lower down may not alter the route the water is using.
Possible remedies
Solutions can include adjusting levels, forming a properly drained channel or correcting bridging finishes. The right detail depends on the wall, drainage and adjoining surfaces.
Want somebody local to look at it?
If you would rather have the damp investigated in person, you can use our help page to describe the problem and decide what sort of specialist you need.