Are you an architect, engineer, or contractor contemplating the adoption of a double roofing system for your projects? The innovation and benefits associated with double roofing are increasingly gaining attention in the construction industry. In this comprehensive guide, we explore the applicability of double roofing and delve into the meticulous process of Onduline Double Roof System installation.


Preparation: Site Inspection and Assessment

Before diving into the installation process, it's crucial to conduct a thorough site inspection and assessment. Here are the key steps:

1. Roof Surface Cleaning 
Ensure a clean and debris-free existing roof surface.

2. Evaluate Roof Condition and Support Structure 
Examine the condition of the roof and support structure. Check rust levels for steel purlins. Assess termite penetration for wooden purlins.

3. Material Estimation and Preparation 
Leverage the Onduline Roofing Calculator on the main page for precise product and accessory estimates.

Installation Process: Step-by-Step Guide

Step 1: Determine Rust and Penetration Levels

Check roof framing and rust levels for steel purlins, apply water-based metal roof paint.
For wooden purlins, use termite control pesticides.

Step 2: Measure Slope and Inspect Purlin Spacing

Install main support battens vertically at 800 cm spacing using tekscrews.
Screw vertical framings to existing purlins.
Apply horizontal battens based on slope: 240 mm on below 10 degrees, 450 mm on 10–15 degrees, 450 mm on >15 degrees.

Step 3: Lay Sheets and Fix Battens

Lay sheets on fixed battens, fixing at the opposite end of prevailing winds.
Apply 1 corrugation side lap with 20 cm end overlap and minimum 1 corrugation side overlap.

Step 4: Use Onduline Screws

Always use Onduline Screw.
Drill screws through the top of the corrugation, aligning with the center of purlins.
Follow specific screw placement guidelines.

Reminders: Minimum of 14 screws/sheet
5 screws at each corrugation at the end lap
3 screws at the first intermediate purlin of sheet
3 screws at the second intermediate purlin of the sheet
3 screws at the third second intermediate purlin of the sheet 

Step 5: Ensure Waterproof Quality

Adhere to overlapping rules to ensure long-term waterproofing.

Step 6: Fix the Ridge

Start fixing the Onduline ridge cap at the opposite end of prevailing winds.
Fasten the ridge at each corrugation of the overlapped sheet.
Maintain a 22 cm minimum overlap between ridges.

Benefits of Onduline Double Roof System Installation


Cost Efficiency and Time Savings:

Reduced installation costs and quicker project completion.

Additional Roof Layer Protection:

Enhanced durability and resistance to extreme weather conditions.

Rust-Free and Wind Resistance:

Onduline's materials provide rust-free longevity and increased wind resistance.

Unique System:

Innovative double roofing approach for optimal results.

15 Years Warranty:

Onduline offers a 15-year warranty, ensuring impermeability and lasting quality.

ONDULINE® Seal smart Technology: A Key Component of Double Roofing Success

Incorporating ONDULINE® Seal smart technology ensures immediate waterproofing at fixing points and overlaps. The technology utilizes micro bitumen exudation to create a secure long-term waterproofing barrier. High-quality bitumen impregnation, homogenous application, and unique overlapping systems make ONDULINE® sheets both watertight and waterproof.


The Role of Embossed Lines and Importance of Bitumen Content

Embossed lines optimize roof durability and ease of installation, reducing necessary overlap distance and assisting installers. The high bitumen content and homogeneous impregnation in ONDULINE® sheets contribute to their exceptional waterproofing capability. With a focus on monolayer technology, ONDULINE® maintains an impregnation rate of 90%, ensuring long-lasting protection.

Elevate Your Roof with Onduline's Double Roof System

Upgrade your roofing system with Onduline's double roofing solution, incorporating advanced technology, efficient installation practices, and durable materials. Experience the benefits of cost efficiency, longevity, and waterproofing excellence. With a focus on innovation and sustainability, Onduline offers a reliable roofing solution for both residential and commercial needs.

Double Roofing Introduction

Double Roofing Installation