Settling Issues – Understanding Building Settlement
When a new house or extension is finished, the structure doesn’t stay perfectly still. The soil underneath shifts, the concrete shrinks, and the whole building settles a bit. That movement is normal, but it can also create cracks and other problems if you don’t know what to look for. Below you’ll get the basics on how long settlement lasts, how to spot trouble, and what to do when you see it.
How Long Does Settlement Take?
Most new builds settle noticeably during the first 12 to 24 months after construction. The biggest changes happen in the first six months when the concrete and mortar lose moisture and shrink. After that, the rate slows down, but small movements can still occur for up to five years, especially if the ground is soft or the foundation was built on fill.
Factors like soil type, weather, and the size of the structure affect the timeline. Clay soils swell when wet and shrink when dry, causing more visible movement. Sandy soils drain quickly and tend to settle faster but with less dramatic cracks. Knowing your local ground conditions helps you predict how much movement is realistic for your project.
Spotting and Dealing With Settling Problems
The first sign of settlement is usually a hairline crack in plaster or drywall. If the crack widens beyond 0.3 mm (about the thickness of a grain of rice) over a few weeks, it’s worth measuring. Use a simple ruler or a crack width gauge – many home‑improvement stores sell cheap ones – and note the size.
Other clues include doors that stick, windows that don’t close properly, or uneven floors you can feel when you walk. A quick way to test floor level is to place a long straight edge (like a 2‑metre piece of wood) across the room and see if any gaps appear underneath.
If you spot cracks larger than 1 mm, or if doors and windows start to misalign, call a structural engineer. They’ll assess whether the movement is within normal limits or if the foundation needs reinforcement. Ignoring serious settlement can lead to costly repairs later on.
For minor cracks, you can often fix them yourself with a flexible filler and a good quality plaster. Apply the filler, smooth it out, and allow it to cure fully before repainting. Remember that the filler should be able to move a little with the building – otherwise it may crack again.
Prevention starts at the construction stage. A well‑compacted sub‑base, proper damp‑proofing, and a correctly designed foundation reduce future movement. If you’re building a new extension, ask your contractor about expansion joints – they give the structure room to move without cracking.
In summary, settlement is a normal part of any new build, but it becomes an issue when cracks widen, doors stick, or floors become uneven. Keep an eye on the first year, measure any cracks, and don’t hesitate to get professional help if the signs point to deeper problems. With a bit of vigilance, you can protect your home and avoid expensive fixes down the line.
