Seamsil Cut Edge Corrosion Treatment

Specialist System for Repairing and Protecting Metal Roof Sheet Edges

Seamsil cut edge corrosion treatment is a silicone-based system designed to stop corrosion on the cut edges and laps of metal roof sheets. It seals and protects vulnerable areas where factory coatings break down, preventing leaks, rust progression and costly roof deterioration.

Total Cladding & Roofing Ltd is approved to install Seamsil as part of HD Sharman’s industry-standard metal roof refurbishment system.

What Is Seamsil Cut Edge Corrosion Treatment?

Seamsil is a specialist silicone system engineered to address one of the most common metal roof failures: cut edge corrosion.
This occurs when the protective coating on a steel roof sheet deteriorates, exposing bare metal at sheet edges, laps and fixings.

Seamsil provides:

• A flexible, long-term corrosion barrier

• Excellent adhesion to exposed steel and coatings

• High UV and weather resistance

• A durable seal that prevents further moisture ingress

It is typically installed before applying Delcote®, creating a complete refurbishment solution.

Why Cut Edge Corrosion Happens

On metal roofs, corrosion typically forms at:

• Sheet overlaps

• Drip edges

• Side laps

• End laps

• Fixing points

These areas are vulnerable because factory coatings wear away first, exposing raw metal to water and oxygen.
If untreated, corrosion spreads beneath the existing coating, eventually causing leaks and significant structural damage.

Seamsil stops this process and stabilises the affected areas.

Benefits of Seamsil Cut Edge Treatment

Seamsil provides several key long-term benefits:

• Arrests corrosion before it spreads

• Prevents further breakdown of steel roof sheets

• Seals laps and edges to stop leaks

• Very high flexibility — adapts to roof movement

• UV and weather resistant for long-term durability

• Suitable for most metal roof profiles

• Compatible with Delcote® for complete metal roof refurbishment

Where Seamsil Is Used

Seamsil is ideal for treating:

• Side laps and end laps

• Corroded sheet edges

• Drip edges over gutters

• Areas where coatings have lifted or flaked

• Corroded fixings and washers

• Roofs on supermarkets, warehouses and industrial units

It is widely used across retail, logistics, manufacturing and commercial buildings.

System Longevity

Seamsil typically provides 15–20+ years of protection when installed correctly and used as part of a full roof refurbishment system.
When combined with Delcote®, lifespan performance can extend even further.

How Seamsil Stops Leaks and Corrosion

The system works by:

• Stabilising and sealing exposed metal

• Forming a flexible, impermeable silicone barrier

• Preventing water from entering laps and interfaces

• Stopping oxidation and coating delamination

This restores the integrity of the roof without replacing sheets.

Installation Process

Inspection: Identify areas affected by cut edge corrosion and coating failure.
Preparation: Clean, abrade and remove loose coatings; treat any active rust.
Application: Apply Seamsil to edges, laps, fixings and joints.
Integration: Combine with Delcote® where full roof protection is required.
Completion: Final inspection and warranty issue.

FAQs

Why do metal roofs need Seamsil?
Because factory coatings deteriorate first at cut edges, leading to exposed metal and corrosion.

Can Seamsil be installed without a full roof coating?
Yes, but it is most effective when used alongside Delcote®.

Is Seamsil flexible?
Extremely — its silicone base allows movement without cracking.

How long does cut edge treatment last?
Generally 15–20+ years depending on exposure and installation quality.

Why Choose Total Cladding & Roofing Ltd?

We are approved installers of Seamsil and Delcote systems.
Our teams perform detailed surveys, accurate specifications and long-term corrosion repair to metal roofing across the UK.

Request a Seamsil Cut Edge Corrosion Survey

We offer nationwide surveys to identify and treat cut edge corrosion using the Seamsil system.
Our specialists will assess your metal roof and provide a detailed refurbishment plan and quotation.

Contact us today to arrange your Seamsil cut edge corrosion survey.