# Overview of Finishes in Building Materials

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.