Overview of Finishes in Building Materials

Don't use the wrong finishes, or else!

Finishes in architecture serve two main functions: protection and aesthetics. They enhance the durability of materials, improve resistance to environmental factors, and contribute to the overall look and feel of a space. Choosing the right finish is as important as choosing the material itself, as incompatible finishes can reduce performance and even cause material failure.

This article provides a summary of common finishes, their correct applications on various building materials, and highlights commonly misunderstood or misapplied combinations.


Types of Finishes

1. Paint

A liquid or mastic composition that, when applied to a surface, forms a protective and decorative coating.

  • Acrylic Emulsion Paint – Used for interior walls and ceilings

  • Enamel/Alkyd / Oil-Based Paint – Durable, used for timber and metal surfaces

  • Epoxy Paint – Industrial-grade, highly resistant to chemicals and abrasion

  • Intumescent Paint – Fire-resistant coating used on steel

2. Powder Coating

A dry finishing process where a free-flowing, dry powder is electrostatically applied and cured under heat. Provides a durable, uniform, high-quality finish.

3. Laminate

A thin layer of material (plastic, veneer, or film) bonded to a substrate. Commonly used for timber products, furniture, cabinetry, and interior wall panels.


Common Building Materials and Compatible Finishes

Material
Suitable Finishes
Common Locations
Notes

Stainless Steel

Brushed, polished, hairline, bead-blasted

Railings, lift interiors, signage

Avoid painting unless special primers are used. Maintains self-protecting oxide layer.

Galvanised Steel

Paint (with primer), powder coat (if degreased and primed), epoxy coating

Railing, linkway/roof structures, fences, structural framing

⚠️ Powder coating directly over galvanised steel without surface prep can cause peeling (outgassing).

Aluminum

Anodising, powder coating, fluoropolymer coating

Facade cladding / rainscreens, window frames

⚠️ Painting directly on aluminum without etching primer leads to poor adhesion.

Timber

Stain, varnish, lacquer, oil, paint

Doors, feature walls panels, flooring

Depends on wood species. Softwoods often painted, hardwoods stained or oiled.

Plywood

Laminate, veneer, clear varnish, paint

Cabinets, wall panelling, ceilings

Interior-grade plywood may warp if improperly sealed.

Gypsum Board

Acrylic emulsion paint, wallpaper, skim coat

Interior walls and ceilings

Ensure joints and screws are flushed before finishing.


Commonly Misunderstood or Misapplied Finishes

Incorrect Pairing
Why It’s a Problem
Better Alternative

Paint directly on aluminum

Poor adhesion due to non-porous surface

Use etching primer or anodise first

Powder coat on galvanised steel (untreated)

Outgassing during curing causes bubbles/peeling

Pre-treat by degreasing and passivating

Epoxy paint on raw timber

Doesn't penetrate wood grain well, peels easily

Use timber sealers or alkyd paint

Emulsion paint on metal

Low adhesion and durability

Use metal primer first


Performance Considerations When Selecting Finishes

When selecting finishes, consider the following:

Consideration
Why It Matters

Material Porosity

Affects adhesion of paints and coatings

Environmental Exposure

UV, moisture, and salt exposure dictate finish durability

Maintenance Level

Some finishes (e.g. clear varnish) require regular reapplication

Fire Rating

Required in some materials like gypsum and steel framing

VOC & Sustainability

Low-VOC finishes are preferred for indoor air quality and green certifications (e.g. Green Mark, BCA Singapore)


Conclusion

Finishes are not just cosmetic — they directly impact a building material's durability, performance, and compliance. Understanding the right finish for the right material is critical to delivering a building that stands the test of time and climate, especially in humid tropical climates like Singapore.

In future articles, we’ll dive deeper into performance-based selection of coatings, green-certified finishes, and detailing for long-lasting performance in architecture.


Source:

  • BCA Good Industry Practices: Wet Trades, Finishes & Cladding

  • SS 345: Specification for aluminium powder coatings (Singapore Standards)

  • "Finishes in Architecture", Architecture Singapore Journal, SIA Publications

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