Construction Flaws You Need to Know About
When you’re adding a conservatory, extending a loft or just buying a new build, you’ll run into a few things that can go wrong. Knowing what to look for saves time, money and headaches. Below we break down the top flaws you’ll see on UK projects and what you can do about them.
Spotting Foundation Problems Early
The foundation is the base of any build, so cracks or uneven settling are red flags. A hairline crack (less than 1 mm) is usually harmless, but once you see a gap wider than 3 mm, call a structural engineer. Look for diagonal cracks that widen over time – that usually means movement in the soil.
Quick checks you can do yourself: use a ruler to measure crack width, tap the floor with a hammer to listen for hollow sounds, and check if doors or windows stick. If anything feels off, get a professional opinion before you pour more money into finishes.
Common Mistakes in Extensions and Loft Conversions
Many homeowners push the limits of permitted development and end up with planning permission headaches. The UK allows a modest rear extension without consent, but if you go beyond 4 m in height or exceed 50% of the original floor area, you’ll need approval. Read the local council’s guidance or ask a qualified architect.
Loft conversions have their own set of pitfalls. Low headroom, inconvenient truss layouts or inadequate fire routes can turn a dream bedroom into a costly retrofit. Measure the headroom at several points – you need at least 2.2 m of clear space for a comfortable room.
Materials matter too. Using cheap, moisture‑prone timber in damp climates leads to rot and warping. Opt for treated joists and a good vapour barrier. It might cost a bit more now, but it prevents repairs later.
Finally, always check the work of subcontractors. A lower‑tier contractor may deliver on time, but if they skip steps or use sub‑standard mixes, you’ll see cracks in walls and floors later. Request a written guarantee and keep records of every material batch.
By keeping an eye on these common flaws, you can catch problems before they become expensive fixes. Remember: a small inspection now beats a big repair later.
