In the renovation of old houses, roof renovation is often one of the most investment-intensive and technically complex stages. The traditional "tear-off and re-roofing" process not only requires a long construction period and generates significant noise but also poses considerable challenges in terms of debris removal and disposal of old tiles. In recent years, a technique known as "stone coated metal roofing tile direct overlay" has gradually become a new favorite in the market. This article will provide a detailed explanation of this efficient solution, focusing on three core aspects: quantity calculation, installation要点, and after-sales service.

I. Direct Overlay: Prerequisites for Saving Time and Effort

The so-called direct overlay involves installing stone coated metal roofing tiles directly onto the existing roof tiles, provided that a professional assessment confirms the original roof structure is safe, the base layer is stable, and there is no severe damage. The advantages of this approach are evident: it eliminates the demolition and removal process, shortens the construction period by approximately 30%-50%, and avoids the dust and noise pollution associated with tear-off.

However, not every old roof is suitable for direct overlay. A thorough pre-construction "physical examination" of the roof is crucial. It is essential to ensure the existing roof is in good condition, structurally sound, and free from significant damage or deformation . If the original roofing shows signs of warping, rot, or potential leaks, these issues must be addressed with localized repairs first to provide a flat and solid base for the new stone coated metal roofing tiles .

II. Scientific Calculation: How to Accurately Estimate Material Quantities

Accurate calculation of material quantities is key to controlling costs and avoiding construction interruptions. The calculation method for stone coated metal roofing tiles differs from traditional tiles, with the core principle being to understand their "effective coverage area."

Taking the common Bond series Roman-style tile available in the market as an example, its typical specifications are as follows:

• Actual Size: 1340mm × 420mm

• Installation Size (Effective Coverage): 1280mm × 370mm (after deducting the overlapping parts)

Calculation Formula:
Quantity per square meter (pieces) = 1㎡ / (Effective Length × Effective Width)

Based on the specifications above:
Effective coverage area per tile = 1.28m × 0.37m ≈ 0.4736 ㎡
Quantity per square meter ≈ 1 / 0.4736 ≈ 2.1 pieces

Procurement Recommendations:
After calculating the theoretical quantity, it is advisable to add an extra 5%-10% for waste factor. This accounts for cutting waste at complex areas such as ridges, eaves, and chimneys, as well as potential damage to some tiles during transportation or on-site cutting.

(Note: Different product series, such as Spanish, Shake, or Roman styles, may have slightly different effective coverage areas. Please be sure to verify the specific technical parameters of the product you are using before placing an order .)