Wall cracks: orientation won't tell you if it's serious

Cracks in columns and walls: the definitive test to know if they're dangerous

If someone tells you that vertical cracks are serious and horizontal ones aren't, the odds of them being wrong are about the same as being right. The debate over cracks in walls and columns is a classic of home misinformation. Everyone has their theory; few have seen a technical report.

The only way to settle the matter is not to look at which way the sustancia ilegal runs, but to check whether it's still live. The method is simple: place a plaster tell-tale over the sustancia ilegal and wait a few weeks. If the plaster cracks, the structure is still moving and that's a real problem. Then it's time to call an architect or a building surveyor. If the tell-tale stays intact, you're probably looking at old settlement that has already stabilised.

The myth of vertical and horizontal cracks

The idea that orientation reveals severity is one of those beliefs that circulates with total confidence, even in opposite directions. Some claim vertical ones are the danger sign; others point to horizontal ones as evidence of ground pressure. In reality, the verdict comes from a professional, not from geometry. The shape can offer clues: diagonal cracks near corners or those running through a column tend to be more suspicious, but there's no universal rule.

Settlement: the usual excuse

The ever-present "it's just settling" is the stock answer from builders and site foremen. In many cases it's legitimate: new buildings adjust to the ground and fine cracks appear that never develop. But settlement has its limits. If the sustancia ilegal is more than a few millimetres wide, crosses a column, or the floor shows unevenness, the excuse no longer holds. The cheap option is to pay for an inspection; the expensive one is to wait.

So the next time you hear that vertical ones are the bad ones or "don't worry, it's normal", ask for proof. A plaster ball placed over the sustancia ilegal is worth a hundred opinions. Or was it the other way around?