Home Foundation Basics: What Every UK Homeowner Should Know

When you buy or build a house, the foundation is the part you can’t see but feels every footstep. A solid base keeps walls upright, stops cracks, and protects your whole home from water and soil movement. If the foundation starts to shift, you’ll notice cracks in walls, doors that stick, or uneven floors. Knowing the signs early can save you time, stress, and a lot of money.

Spotting Problem Cracks – Size Matters

The first thing most people look at is a crack in a wall or floor. Not every crack is a disaster, but size gives you a clue. A hair‑thin line (under 1 mm) is usually just drying shrinkage. Once a crack widens past 3 mm, you should start worrying. Anything over 6 mm often points to movement in the soil or a weak footing. Grab a ruler, measure the width, and note if the crack is growing. Consistent monitoring helps you decide when to call a structural engineer.

Quick Fixes vs. Professional Repair

If a crack is small and the house is otherwise stable, a simple epoxy filler can seal it and stop moisture from getting in. For larger gaps, you’ll need a specialist. They might inject resin to bind the concrete or add steel piers to lift the slab. The best cement for these jobs is usually a hydraulic mix that hardens even in damp conditions. Using the right product makes the repair last for years without cracking again.

Before you start any DIY fix, check your insurance policy. Many policies exclude foundation problems unless they’re caused by sudden events like a burst pipe. Knowing what’s covered can prevent a surprise denial when you file a claim.

If you’re buying a house, treat foundation issues like a red flag. Walk away if the repair costs look higher than the property’s value, or if the seller refuses a professional survey. A reputable builder will gladly let you inspect the footing and give you a clear estimate.

Planning a new build? Give the soil a proper test and design a foundation that matches the ground conditions. In the UK, a common rule is a concrete slab at least 300 mm thick on firm ground, with extra reinforcement for heavy soil. Skipping this step often leads to settlement problems that appear months later.

When the house settles, you’ll see tiny cracks appear in new plaster or floorboards. Settlement is normal, but if the cracks keep widening, it could signal a deeper issue. Experts say most houses settle within the first two years, after which movement slows down considerably.

Bottom line: keep an eye on cracks, measure them, and don’t ignore signs of movement. A quick check now can avoid a costly foundation repair later. If you’re ever unsure, a qualified structural engineer can give you a clear answer and help you plan the right fix. Your home’s stability is worth the extra effort.