Reference
Facade & finishing glossary
Plain-English definitions of the facade, surface, coating and rectification terms that come up on a handover — for anyone specifying, procuring or closing out finishing work.
- Airless spray
- A spraying technique that pushes paint at high pressure through a fine tip to atomise it without compressed air, giving fast coverage and a heavy, even film. It is commonly used for large facade areas and primers.
- Anodised finish
- An electrochemical treatment that thickens the natural oxide layer on aluminium to give a hard-wearing, colour-stable surface. Anodised finishes cannot be re-anodised in place, so on-site rectification relies on specialist colour-matched touch-up systems.
- Back-charge
- A cost one party deducts from or bills to another to recover the expense of fixing that party's defective or incomplete work. On finishing trades, back-charges often arise where damage, poor colour match or failed seals require rework.
- Backing rod
- A compressible foam rod pushed into a joint before sealant to control the sealant depth and create the correct hourglass profile. It also stops the sealant bonding to the back of the joint, which would otherwise restrict movement (three-sided adhesion).
- Colour matching
- The process of measuring and reproducing an existing colour so a repair or new coating blends with the surrounding finish. Best practice is to prepare a sample and confirm the match on site under actual lighting before mass application.
- Defect list (punch list)
- The register of incomplete or non-conforming items identified at or before handover that must be rectified. A long facade and finishes defect list can delay sign-off, hold up following trades and put retentions at risk.
- Defects liability period (DLP)
- The set period after practical completion during which the contractor must rectify defects that appear, at their own cost. Retention money is commonly held until the DLP ends and outstanding defects are closed out.
- Electrostatic spray painting
- A spray method that gives the paint particles an electric charge so they are attracted to an earthed metal surface, wrapping around edges and reducing overspray. It is well suited to on-site recoating of railings, frames and other metalwork without full removal.
- Facade commissioning
- The structured checking, testing and sign-off of a facade to confirm it performs as designed, including water penetration and sealant integrity checks. It confirms the envelope is weathertight before the trade hands over.
- French polishing
- A traditional timber finishing method that builds many thin layers of shellac, hand-applied with a pad, to produce a deep, high-gloss surface. It is used on quality joinery and feature timber, and is repaired by re-bodying rather than stripping the whole piece.
- Hold point
- A stage in the ITP where work must stop until a nominated party inspects and approves it before the next step begins. Missing a hold point can mean work is re-opened or rejected later.
- Inspection and Test Plan (ITP)
- A document that sets out the inspection and testing points for a work package, who signs off each hold or witness point, and the records required. On facade and finishing works it evidences that each stage met specification before the next trade proceeded.
- Mill finish
- Aluminium in its raw, untreated state straight from the mill, with no coating or anodising applied. It marks and oxidises easily, so it is usually coated or protected before or after installation.
- Movement (expansion) joint
- A deliberately sized gap, filled with a flexible sealant over a backing rod, that allows building elements to expand, contract and move without cracking the finish. Correct joint width-to-depth ratio is critical to how the sealant performs over its life.
- Powdercoat (powder coating)
- A dry finish where charged powder is electrostatically applied to metal and cured under heat to form a hard, durable layer, common on aluminium facade framing and windows. Damage or fading is generally repaired on site by colour-matched spray rather than by re-baking, which would mean removing the section.
- Practical completion
- The contractual milestone where the works are complete enough for the principal to use them, apart from minor defects and omissions still to be finished. It typically triggers handover, release of part of the retention and the start of the defects liability period.
- Primer
- A preparatory coat applied to a substrate to improve adhesion, seal porous surfaces or promote sealant bond. Skipping or mismatching the primer is a common cause of coating and sealant failure.
- Rectification
- The repair or making-good of defective, damaged or non-conforming work to bring it back to specification. On facades and finishes this covers recoating, resealing, colour-matched touch-ups and joinery repair, often across several trades.
- Retention
- A percentage of each payment withheld by the principal as security that the contractor will complete the works and rectify defects. It is usually released in stages at practical completion and at the end of the defects liability period.
- Silicone sealant
- A flexible, weather-resistant sealant used to close joints against water and air. Its performance depends on correct joint design, clean substrates and, where needed, a compatible primer and backing material.
- Substrate
- The underlying surface or base material a coating or sealant is applied to, such as aluminium, glass, timber, stone or plasterboard. Correct surface preparation of the substrate largely determines how well the finish adheres and how long it lasts.
- Two-pack (2K) coating
- A high-performance paint or finish supplied as two components mixed before use, curing by chemical reaction to a hard, durable surface. It is used where a tough, long-lasting finish is needed on metal and joinery, and has a limited working time once mixed.
- Weather seal
- A sealant joint on the external face of a facade whose job is to keep water and air out of the building. It is the first line of defence at panel and window perimeters and is a frequent source of handover defects if poorly tooled.
- Wet seal
- A remedial method of restoring weathertightness by applying a continuous silicone seal over an existing joint or glazing line, typically where original seals have failed. It is used for targeted facade repairs without dismantling the panel.
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