How to Write a Paint Specification for Construction Projects
Guide for architects, engineers and project managers on preparing paint specifications. Standards, surface-based product selection and system selection tables.
Why Paint Specifications Matter
In construction, a paint specification documents technical performance, product approvals and application conditions. Incomplete specs lead to early defects, warranty disputes and cost overruns.
Specification Components
- 1Scope — Areas, surface types and square meterage
- 2Technical Properties — VOC limits, coverage rates, drying times
- 3Product Approvals — Accepted brand/product list or equivalent criteria
- 4Application Conditions — Temperature, humidity, surface preparation
- 5Quality Control — Dry film thickness (DFT) and adhesion tests
- 6Warranty — Product and application warranty terms
Area-Based Product Selection Table
| Area / Surface | Recommended System | Min. DFT | Standard |
|---|---|---|---|
| Interior wall — residential | Water-based matt | 40 µm | EN 13300 |
| Wet area | High moisture-resistant water-based | 50 µm | EN 13300 |
| Exterior facade — plaster | Elastomeric acrylic | 80 µm | EN 1062 |
| Metal door/window | Alkyd enamel + anti-rust | 60+40 µm | ISO 12944 |
| Industrial floor | Epoxy 2K | 150 µm | EN 1504 |
| Steel structure | Epoxy anti-rust + PU | 80+60 µm | ISO 12944-C3 |
Technical Requirements
| Property | Exterior Min. | Interior Min. |
|---|---|---|
| Water tightness (w1) | < 0.1 kg/m²·h | — |
| Vapor permeability (sd) | < 0.14 m | — |
| Contrast ratio | ≥ 0.95 | ≥ 0.95 |
| VOC (Cat. A) | < 40 g/L | < 30 g/L |
Frequently Asked Questions
Who prepares a paint specification?
Architects, project engineers or paint consultants. MST Paint's technical team provides free support for project-specific spec drafting.
What do ISO 12944 C3 and C4 mean?
C3 is urban industrial, C4 is coastal or heavy industrial. Coating system and DFT values change by environment class.
Are equivalent products accepted in specs?
Yes, using "approved equivalent" language with technical criteria (DFT, coverage, VOC, test certificate).
