Top 10 New Build Snagging Defects — and How to Get Them Fixed

Buying a new-build should be hassle-free, but hidden workmanship issues can cause leaks, damp, or costly repairs later. A professional New Build Snagging Survey highlights these problems so the developer puts them right.

At ONFORM, we inspect new homes across Bournemouth, Christchurch, Poole, Ringwood, Salisbury, Fordingbridge, New Forest, Hordle, Lymington, Dorset, Hampshire, Wilshire and surround areas. Here are the 10 most common defects we find, and how they should be resolved.

1) Cavity trays and weep vents missing, blocked or poorly detailed

Why it matters: Without correctly installed cavity trays and clear weep vents, water cannot discharge, leading to damp inside walls.
Fix: Ensure trays are continuous with proper stop-ends, aligned with clear weep vents at correct centres. Remove render, mortar or obstructions and reinstate neat openings.

2) Bridged damp-proof course (DPC)

Why it matters: Render, paving, soil or insulation bridging the DPC allows rising damp.
Fix: Maintain minimum 150mm clear upstand; cut render back, lower paving/soil, and add drip beads where needed.

3) External penetrations not sealed correctly

Why it matters: Gaps around pipes, vents and cables cause water ingress, drafts, heat loss and an entry point for insects.
Fix: Use correct collars, gaskets and sealants while maintaining fire, acoustic and weather ratings.

4) Incorrect drainage to level thresholds/doors

Why it matters: Missing or poorly laid drainage channels let water pool against doors, flooding interiors.
Fix: Install linear drainage with proper falls and keep external levels below the damp-proof course.

5) Downpipes not fitted or connected correctly

Why it matters: Misaligned downpipes or missing connections cause walls and foundations to become saturated.
Fix: Reset brackets and outlets, connect to gullies correctly, and check gutter falls.

6) Insulation incorrectly fitted

Why it matters: Gaps, compression and thermal bypass reduce energy performance and can cause condensation.
Fix: Refit insulation continuously.

7) Doors & windows not fitted correctly

Why it matters: Poor alignment leads to drafts, leaks and security issues.
Fix: Re-square frames, adjust hinges and locks, seal perimeters correctly, and ensure trickle vents are installed.

8) Kitchen & bathroom defects

Why it matters: Misaligned units, poor sealing and loose fittings can lead to leaks and damage.
Fix: Re-align units, reseal joints properly, and re-fix or replace faulty fittings.

9) Internal doors not latching or catching

Why it matters: Poorly fitted doors can damage frames and fail to meet fire resistance standards.
Fix: Adjust hinges and keeps, plane doors where needed, and confirm fire doors meet gap and hardware specifications.

10) Poor plaster, decoration and sealant finishes

Why it matters: Rushed or incomplete finishes make a new home look poor and can leave surfaces unprotected.
Fix: Repaint or redecorate with correct surface prep, and replace messy or missing sealant with neat, continuous application.

Why a professional snagging survey matters

While some snags are cosmetic, others - like drainage, DPCs or insulation - can cause long-term structural or performance issues. A professional snagging survey by ONFORM ensures:

• Every defect is independently recorded with photos.

• You have clear evidence to present to your developer.

• Issues are resolved before they become costly.

📞 Contact ONFORM today to book your New Build Snagging Survey in Bournemouth, Christchurch, Poole, Ringwood, Salisbury, Fordingbridge, New Forest, Hordle, Lymington, Dorset, Hampshire, Wilshire and surrounding areas.