Snagging at the End of a London Building Project: What to Check and How

Snagging refers to the systematic identification of defects, incomplete works, and non-conformances at the end of a construction project — before practical completion is formally certified.

• **Practical completion vs. final completion:**
• In most standard building contracts, there are two key completion milestones:
• •**Practical completion** — the point at which the works are substantially complete and the client can take possession and use the property. Minor snags may remain at this point.
• •**Final completion** — the point at which all outstanding snagging items have been resolved and the contractor's liability for defects under the contract is satisfied.

Between practical completion and final completion, a 'defects liability period' (typically 6–12 months in residential contracts) runs during which the contractor is obliged to return and rectify defects that appear.

**Who should produce the snagging list:** A conscientious contractor should produce their own internal snagging list and resolve all items before presenting the works to the client. The client walk-through should then be the final check — not the first time defects are being recorded. A contractor who presents works with obvious unresolved defects and waits for the client to find them is not operating to a professional standard.

A thorough snagging walk-through should cover every room and every element of the works systematically. The following is a room-by-room and element-by-element guide:

• **External and structural:**
• •External finish — render, masonry, or cladding: no cracks, missing pointing, or poorly finished sections
• •Roof covering — no missing tiles/slates visible, no poorly dressed flashing, lead correctly formed at abutments and valleys
• •Rooflights and dormer windows — operation tested, no condensation between panes, flashings correctly formed
• •External doors — opening, closing, and locking correctly; threshold weathertight
• •Windows — opening lights operate correctly; no visible gaps in seals

• **Floors:**
• •No hollow or loose tiles (tap test)
• •No squeaking boards (walk test)
• •Junctions between different floor finishes are neat and level
• •No chipping or cracking of floor tiles at waste positions, door thresholds, or heavy furniture positions

• **Walls and ceilings:**
• •No cracking at joints between plasterboard sheets (hairline cracking at taped joints is common and almost always opens up in the first heating season — but significant cracks, hollowing plaster, or cracking at structural junctions should be flagged)
• •No visible shadows on painted surfaces from poor plasterboard fixing
• •Ceiling/wall junctions: neat, no gaps at coving or no-coving junction
• •Outlet and switch face plates: level, flush, fully fixed — no exposed gap at back box

• **Joinery:**
• •All doors open and close smoothly without catching or rattling
• •Door furniture (handles, hinges, latches) complete and tight
• •Skirting board and architrave: mitred corners tight, no visible gaps, fully fixed — no movement
• •Staircase: balustrade rigid (no movement), baluster spacing compliant (must not allow a 100mm sphere to pass through — Building Regulations requirement), tread and riser joints tight

• **Kitchens:**
• •All cabinet doors and drawers open and close without catching; soft-close mechanisms operating correctly
• •Worktop joints tight and sealed
• •Upstand seal between worktop and wall tile fully sealed — no gap
• •Appliances connected and operational
• •Splash-back complete and fully grouted/sealed

• **Bathrooms:**
• •All grout lines complete — no voids or cracked grout, particularly at shower enclosures
• •Silicone seal complete at all junctions — bath-to-wall, shower tray-to-wall, basin-to-wall. Silicone should not be cracked, gapped, or missing
• •WC pan firmly fixed to floor — no movement
• •All tap and valve fittings: tight, no drips
• •Shower enclosure: glass panels fully installed and sealed; door opens and closes without dragging on tray
• •Towel rail and accessories: fixed and in correct position

• **Mechanical and electrical:**
• •All sockets and switches: operational (test with a phone charger)
• •All light fittings: operational and correctly fitted
• •Heating system: operational, all radiators or UFH zones confirmed working
• •Ventilation: extractor fans operational in kitchen and bathrooms
• •Any alarm systems: operational and installed as specified

• **Documenting snags:**
• Snags should be documented in writing — not verbally. The best approach is a written (or photographed) snagging list with:
• •Item description
• •Location (room/element)
• •Photograph where helpful
• •Agreed remediation (what will be done)
• •Target date for completion

**Agreeing the snagging list:** Both client and contractor should agree the snagging list before it is finalised. Items where there is a disagreement about whether something is a defect or a design/specification issue should be identified and discussed explicitly — not left ambiguous.

**Retention:** In most standard residential building contracts, a proportion of the contract sum (typically 5%) is retained by the client until the defects liability period has passed and all snagging items are complete. This gives the contractor a financial incentive to complete the snagging and return for any post-completion defects. If no retention is provided for in your contract, the leverage to get snagging items completed is reduced.

• **What is NOT a snag:**
• Some things that clients sometimes raise as snags are actually:
• •**Shrinkage cracking** at plasterboard joints — almost universal in the first heating season; the contractor should return to fill and redecorate (this is a valid defect liability call-back, not something that should hold up practical completion)
• •**Naturally occurring variation** in natural materials (stone, slate, timber) — variation in colour and character is inherent; it is only a defect if it falls outside the agreed specification or sample
• •**Client change of mind** about design decisions that were agreed before works began — this is a variation, not a snag, and will typically require payment

**When snagging reveals more significant issues:** If the snagging walk-through reveals defects that go beyond minor finishing items — significant structural cracking, failed waterproofing, non-compliant work — these should be treated as a dispute rather than a snagging item, and independent advice should be sought. An independent building surveyor or specialist can assess whether the defect is within acceptable tolerance, requires remediation, or constitutes a contract breach.