Aluminum Roofing Sheet Purchasing Guide: From Selection to Installation, Every Step Must Be Correct

The aluminum roofing tile market is growing rapidly, but this has also led to inconsistent product quality and a mix of reputable and unreliable suppliers. Buyers who are not careful may end up purchasing products that 'look the same but perform drastically differently.'

I. Four pitfalls in the selection phase

Pitfall 1: Focusing only on thickness, ignoring alloy composition

'Our tiles are 1.2 millimeters thick'—this is a common sales tactic. But the problem is that different alloys vary drastically in strength and corrosion resistance.

With the same thickness of 1.2 mm, the tensile strength of 1060 pure aluminum is only about 70 MPa, while that of 3003 aluminum-manganese alloy reaches over 95 MPa, and that of 5052 aluminum-magnesium alloy exceeds 195 MPa.

Tips to avoid pitfalls: Ask about the alloy grade, not just the 'thickness'. Coastal projects require at least 3003, preferably 5052; inland projects can barely use 1060, but 3003 is more reliable.

Pitfall 2: Blindly believing in the word 'fluorocarbon' without asking about the fluorocarbon content.

'Our boards are fluorocarbon coated'—just like roll-coated boards, fluorocarbon coatings are also graded.

The national standard requires that the fluorocarbon resin content in fluorocarbon coatings be no less than 70%. Some manufacturers, in order to reduce costs, reduce the content to 50% or even lower. While the test reports may label them as 'fluorocarbon,' their actual weather resistance is significantly worse.

Tips to avoid pitfalls: Request a third-party testing report from the supplier for the coating, specifically checking the 'fluorocarbon resin content.' If it's below 70%, it's not recommended for outdoor projects.

Pitfall 3: Neglecting panel design leads to poor drainage and leaks.

The shape (waveform) of aluminum roofing sheets directly affects drainage efficiency and wind resistance.

Tips to avoid pitfalls: Select the appropriate corrugated sheet type based on the annual rainfall and basic wind pressure of the project location. Generally, the 750 or 840 type is recommended for industrial plants, while the 836 type is recommended for residential buildings.

Pitfall 4: Failure to calculate purlin spacing will cause the boards to warp after installation.

The load-bearing capacity of aluminum roofing sheets is closely related to the spacing between the purlins. If the purlin spacing is too large, the aluminum roofing sheets will show obvious indentations when stepped on or when snow accumulates.

Avoidance of pitfalls: Calculate a reasonable purlin spacing based on the slab thickness, slab type, and climate conditions of the region of use. It is generally recommended not to exceed 1.5 meters; confirm the specific values with the supplier's technical personnel.

II. Acceptance Phase

1 : Only look at the surface and ignore the cut cross-section.

Many buyers only check for scratches on the surface when receiving goods, ignoring the more important factor—the quality of the base material.

The cross-section of primary aluminum from large manufacturers is fine and uniform, with a clear metallic luster; the cross-section of recycled scrap aluminum has large particles and a dark color. This difference will manifest as a gap in corrosion resistance after two or three years.

Avoidance method: Cut off a small piece of waste material and examine the cut surface. If possible, take a sample for spectral analysis; the composition will be immediately apparent.

2 : Failing to measure coating thickness, being misled by the 'thin board, thick paint' claim.

Some manufacturers use very thin substrates but apply very thick paint, misleading buyers into thinking the boards are very 'solid'.

Tips to avoid pitfalls: Carry a magnetic thickness gauge (they cost a few hundred yuan each) with you to measure the coating thickness. Fluorocarbon coatings should be ≥20μm thick on one side, and polyester coatings should be ≥15μm thick on one side.

III . Five Key Technical Points for Aluminum Roofing Tile Installation

1. Purlin Spacing Control

The load-bearing capacity of aluminum roofing sheets is directly related to the spacing between the purlins. It is recommended that the purlin spacing not exceed 1.5 meters, but the specific spacing should be calculated based on the sheet thickness, sheet type, and climatic conditions of the region where it is used.

2. Fastener Selection

Stainless steel or aluminum self-tapping screws must be used; ordinary iron nails are strictly prohibited.

3. Expansion Joint Installation

Aluminum has a coefficient of thermal expansion of approximately 23 × 10⁻⁶/℃, which is higher than that of steel. For long-span roofs (≥40 meters), expansion joints or sliding connectors should be installed to release stress caused by thermal expansion and contraction.

4. Overlap length

The longitudinal overlap length of aluminum roofing sheets should not be less than 200 mm, and the transverse overlap should have at least one crest. The overlap should be reinforced with special waterproof tape or sealant.

5. Precautions for trampling

During installation, try to step on the purlins and avoid stepping directly on the middle of the slab span.

IV . One table to understand: Good aluminum roofing sheets vs. inferior aluminum roofing sheets

V. Summary

There's no perfect answer when it comes to purchasing aluminum roofing sheets, but there are better options. From selection to acceptance to installation , as long as the standards are clearly defined and a responsible supplier is chosen, these pitfalls can be avoided in advance.

Truly professional procurement doesn't choose the 'cheapest,' but rather the 'least risky.'

Why choose DIXXIN as your project supplier ?

Advantage 1: Complete range of specifications, including alloys, thicknesses, and plate shapes.

DIXXIN offers a variety of aluminum alloys, including 1060, 3003, 3004, and 5052, with thicknesses ranging from 0.5mm to 2.0mm. Whatever your project's requirements, we can match them.

Advantage 2: Quality is verifiable, and each batch is traceable.

Every batch of Yucheng aluminum roofing sheets undergoes alloy composition testing, coating thickness testing, and bending testing. Customers are welcome to witness the process on-site or commission third-party testing.

Advantage 3: Extensive experience, verifiable project case studies.

DIXXIN Aluminum Roofing Sheets are exported to Southeast Asia, the Middle East, Africa, and other regions, covering various projects including industrial plants, commercial buildings, and residential homes. If needed, we can provide case studies of similar projects and customer feedback.