UNDERPINNING SPECIALISTS Foundations sinking - Cracks in walls? Doors and Windows not closing? WHAT IS UNDERPINNING? WHY DO WE NEED UNDERPINNING? The word underpinning is used to describe a problem situation, that affects a number of buildings, who's owners find that their building is sinking - cracking of walls - cracking of floors - windows and doors will not open or close properly. CAUSES OF NEEDING UNDERPINNING This is due to three main reasons, the most common cause is due to footings set in reactive soils. It does not matter how good the footings are, in coastal Queensland, we are subject to prevailing east/southeast winds, that bring quite a lot of rain at times. The buildings east facing flank, gets wetter than the west facing flank, swelling the ground unevenly, resulting in fracturing of slabs and walls.