How Does a Light Steel Roof Work?
On light steel buildings, the roof is built on cold-formed steel roof trusses. The truss system is manufactured in a factory and assembled on site within a few days. Any roof covering can be chosen on top of these trusses: tile, trapezoidal sheet, or sandwich panel. All three options are technically compatible; the real difference lies in budget, aesthetics, and insulation performance.
A light steel roof truss is not the roof covering itself — it's the load-bearing frame system. Which covering you place on top is a separate decision. This article is written to make that decision easier.
Option 1: Tile Roof
This is Turkey's most widely recognized roof covering type. It is frequently chosen for light steel structures, especially in residential projects.
| Property | Value |
|---|---|
| Material types | Concrete tile, ceramic tile, natural tile |
| Approximate cost (material + labor) | 350 – 600 TL/m² |
| Installation time (100 m²) | 3 – 5 days |
| Lifespan | 30 – 50 years |
| Thermal insulation | Moderate (extra insulation required) |
| Sound insulation (rain) | Good |
| Maintenance required | Low (replacing broken tiles) |
| Aesthetics | Traditional, residential look |
Advantages:
- Provides a classic residential aesthetic; easy to get municipal and neighbor approval.
- The roof type that best insulates against rain noise.
- Individual broken pieces can be replaced; no need to renew the entire roof.
- Excellent compatibility with light steel roof trusses; no extra reinforcement needed.
Disadvantages:
- The slowest option with the highest labor cost.
- Provides no thermal insulation on its own — mineral wool must always be added beneath the roof.
- A sloped roof is mandatory (min. 30% slope); cannot be applied to flat or low-slope roofs.
Tile is ideal for residential projects, especially when aesthetics matter and long-term maintenance ease is desired. Most of our customers in the Tekirdağ and Thrace region prefer tile.
Option 2: Trapezoidal Sheet
This is produced by shaping galvanized or painted steel sheet. Standard in industrial structures, this option can also be used in residential projects.
| Property | Value |
|---|---|
| Thickness options | 0.40 – 0.70 mm |
| Approximate cost (material + labor) | 180 – 320 TL/m² |
| Installation time (100 m²) | 1 – 2 days |
| Lifespan | 20 – 35 years (depending on quality) |
| Thermal insulation | Poor (extra insulation mandatory) |
| Sound insulation (rain) | Poor (mineral wool required) |
| Maintenance required | Low–moderate (repainting) |
| Aesthetics | Industrial look |
Advantages:
- The fastest installation: large panels cover quickly, keeping labor costs low.
- The lowest material cost.
- Can be applied to flat or low-slope roofs (min. 5% slope).
- Wide range of color options; produced in the RAL color scale.
Disadvantages:
- Provides zero thermal insulation on its own — mineral wool underneath is mandatory.
- The roof type that transmits the most rain noise; unlivable without 50 mm of mineral wool beneath it.
- Municipal aesthetic review may be unfavorable for residential projects.
- Long-term risk of paint fading and rust (choose galvanized).
Ideal for warehouses, garages, agricultural structures, and industrial facilities. Suitable when speed and budget are the priority and aesthetics are secondary. For residential projects, be sure to add mineral wool underneath.
Option 3: Sandwich Panel
This is a modern roof covering produced by compressing thermal insulation material between two metal surfaces. In recent years it has become increasingly common in residential projects as well.
| Property | Value |
|---|---|
| Fill types | Polyurethane (PUR/PIR), mineral wool (fire-rated) |
| Thickness options | 40 – 120 mm |
| Approximate cost (material + labor) | 550 – 950 TL/m² |
| Installation time (100 m²) | 2 – 3 days |
| Lifespan | 25 – 40 years |
| Thermal insulation | Very good (no extra insulation needed) |
| Sound insulation (rain) | Moderate–good |
| Maintenance required | Very low |
| Aesthetics | Modern, flat or lightly sloped look |
Advantages:
- The best indoor thermal performance — cool in summer, warm in winter. No additional roof insulation needed.
- A single product completes both covering and insulation; installation is fast and clean.
- Delivers long-term energy savings; heating/cooling costs drop.
- Low load on the light structure; simplifies truss design.
- Can also be comfortably used on low-slope roofs.
Disadvantages:
- Higher upfront cost than tile or trapezoidal sheet.
- Damage (scratches, holes) may require replacing the entire panel.
- In some areas its appearance may not suit traditional residential neighborhoods.
- For fire rating, mineral-wool-filled panels are recommended over polyurethane (A2 fire class).
When energy efficiency is the priority — especially in regions with extreme heat or cold, in large residential projects, or when modern architectural design is desired — sandwich panel is the most efficient option. Its long-term low-maintenance advantage is also significant.
Three-Way Comparison Table
| Criterion | Tile | Trapezoidal Sheet | Sandwich Panel |
|---|---|---|---|
| Cost (m²) | 350–600 TL | 180–320 TL | 550–950 TL |
| Installation speed | Moderate | Fast | Fast |
| Thermal insulation | Moderate* | Poor* | Very Good |
| Sound insulation | Good | Poor* | Moderate |
| Aesthetics (residential) | Traditional | Industrial | Modern |
| Long-term maintenance | Easy | Moderate | Very Little |
| Lifespan | 30–50 years | 20–35 years | 25–40 years |
| Slope requirement | Min. 30% | Min. 5% | Min. 5% |
* Performance improves significantly with the addition of mineral wool.
Roof Slope and Design Constraints
The choice of roof material directly determines the roof slope angle:
- Tile: A minimum 30% (approximately 17°) slope is required. Water pools and leaks on flat or low-slope roofs.
- Trapezoidal sheet: Usable from 5% (approximately 3°) slope upward. Suitable for flat-looking structures.
- Sandwich panel: Applied from 5% slope upward. Ideal for a modern flat-roof aesthetic.
Floor height and zoning conditions may restrict roof slope. Some municipalities require a tile roof — check the zoning status document before starting your project.
Which Roof Should You Choose?
| Situation | Recommendation |
|---|---|
| Residential, traditional look, long lifespan | Tile |
| Residential, energy efficiency priority | Sandwich Panel (mineral wool) |
| Warehouse, garage, agricultural structure | Trapezoidal Sheet |
| Modern architecture, low-slope roof | Sandwich Panel |
| Limited budget, fast delivery | Trapezoidal Sheet + Mineral Wool |
| Quiet roof, rain noise is bothersome | Tile |
| Long-term maintenance-free use | Sandwich Panel |
Frequently Asked Questions
Is snow load a problem for a light steel roof?
No. Light steel roof trusses are calculated according to snow load under TBDY 2026. Standard snow load calculation for the Thrace and Tekirdağ region is already included in our truss design. Additional calculation is performed in regions with heavier snowfall (rural Edirne, higher elevations).
Is condensation a problem with sandwich panel?
A quality sandwich panel's interior surface prevents condensation. The point that needs attention is the roof-wall junction details and ridge flashing application. If these details are not done correctly, condensation can occur at edge points.
Does a trapezoidal sheet roof cause dampness?
If mineral wool is not applied beneath trapezoidal sheet, condensation forms between the sheet and the roof truss, and the truss can rust. Mineral wool both prevents condensation and provides sound and thermal insulation. When trapezoidal sheet is chosen, mineral wool cannot be skipped.
Can I change the roof later?
Yes. The light steel roof truss supports different covering types. Years after trapezoidal sheet is installed, you can switch to sandwich panel or tile. Conversion is possible as long as the roof slope and truss design allow it.
The roof material decision varies by project, budget, and zoning conditions. Call 0553 543 02 12 or share your project through the contact form; let's determine the best option for you together.