MASC - Gutter seam system for watertight metal gutters, clamp, Nanofil seam insert & sealing rivets, choose from variants

✔ Watertight gutter joints in no time – No soldering, completely weather-independent
✔ Professional system as a set or individual components – Gutter seam clamp, Nanofil seam insert & sealing rivets
✔ Permanently plastic & self-welding – Extremely durable for decades
✔ Enormous savings in time and costs – Ready for use immediately after installation
✔ Universally applicable – Perfect for semicircular metal gutters made from all common materials 

The perfect professional gutter connection for sheet metal workers & roofers

The MASC - Gutter seam clamp & seam insert (Nanofil) is the innovative system solution for sheet metal workers, roofers and plumbers to efficiently create completely watertight joints in semicircular metal gutters. Forget laborious soldering in wind and weather: With the professional combination of the nickel-plated gutter seam clamp and the highly elastic Nanofil sealing insert, you can quickly create precisely fitting, watertight and mechanically extremely strong joints.

Especially for demanding roofing projects, this professional tool from MASC delivers consistent, professional results and maximum safety on the job site.

An overview of all MASC system variants and components

To make sure you’re perfectly equipped for every gutter and project size, the MASC system is available in the following configurations and individual components:

1. MASC gutter seam clamp 33 (Item no. RNZ33)

• The solution for large gutters: This nickel-plated special clamp features a movable jaw and is precisely designed for 33-size gutters (6-piece) sized. It provides the optimal pre-tension for the gutter seam before riveting.

2. MASC gutter seam clamp 28 (Item no. RNZ28)

• The solution for standard gutters: Identical in design to the larger version, but perfectly suited to 28-size gutters (7-piece). Also nickel-plated to a high standard and equipped with a movable jaw for maximum precision.

3. MASC gutter seam set (Item no. RNS)

• The practical combo pack: Ideal for getting started quickly or for smaller projects. The set includes 1 roll of Nanofil seam insert (6 m) and 200 matching stainless steel sealing rivets (3.2 mm).

4. MASC Nanofil seam insert (Item no. NE)

• The key to sealing: A 25 mm-wide sealing insert on a 6-meter roll. The ready-to-use, non-reactive material remains permanently flexible, age-resistant, and self-bonding for decades.

5. MASC sealing rivets (item no. DNE32)

• For mechanical fastening: High-strength rivets made of Stainless steel (3.2 mm) in a handy Pack of 200. They ensure lasting contact pressure across the gutter connection through the sealing insert.

Work efficiently and save time on the roof

With the MASC gutter seam system, you can work on gutter connections much faster and more flexibly than with traditional methods such as soft soldering. Its simple mechanical application offers:

✔ Completely weather-independent (Can also be installed in cold or damp conditions)
✔ No heat generated (ideal for pre-coated or delicate gutters)
✔ Works immediately with no cooling or drying times
✔ Huge cost savings by reducing time spent on the job site 

Versatile & eco-friendly for every project

The Nanofil seam insert is a true all-rounder in sheet metalworking supplies:

• Material compatibility: Highly compatible with most metallic building materials and other materials.
• Durability: Completely resistant to aging, weather, UV, water, and vapor, as well as dimensionally stable and solvent-free.
• Sustainability: Physiologically safe, environmentally friendly, and with an almost unlimited shelf life.

Ideal for:

• Half-round metal gutters for new builds & renovations.
• Secure gutter connections in regions with heavy snowfall or strong winds.

Application & professional tip for the job site

How to use:

1. Stick the Nanofil insert to the inside of the cleaned gutter, peel off the backing strip, and join the gutters.
2. Securely prestress the seam with the silver MASC gutter seam clamp.

Rivet the connection directly through the sealing insert using stainless steel sealing rivets spaced 20 to 25 mm apart. Important: Always start at the gutter bead, drill one hole at a time, and rivet it immediately.

💡 Sheet metal worker tip:

For easily accessible gutters, position the seam directly in the bracket area and set the rivets just beside the gutter bracket. When using the gutter seam clamp, attach or slide the gutter bracket into place only after the seam has been fully formed. For a flawless finish, the rivets can then be touched up with a suitable paint pen.

Why the MASC gutter seam system is a must-have

The major advantage lies in the unbeatable combination of Cost-effectiveness, durability, and easy installation. You achieve permanently watertight gutter joints with minimal tool use and become completely independent of the weather.

Get original MASC system components from the well-stocked roofing supply store at your roof specialist Roofify – for professional sheet metal work at the highest level.

The MASC gutter seam clamp & seam insert (Nanofil) is a mechanical system for sheet metal workers, roofers, and plumbers to create watertight joints in semicircular metal gutters without soldering. Depending on the task, clamps, seam insert, sealing rivets, and a set are available as matching system components.

Key features and technical specifications

• Gutter sizes: Gutter seam clamps for size 28 gutters (7-piece) and size 33 gutters (6-piece).
• Clamp design: Nickel-plated finish with movable jaw to pre-tension the gutter seam before riveting.
• Seam insert: Nanofil sealing insert, 25 mm wide, on a 6 m roll.
• Seam insert properties: Non-reactive, permanently plastic, self-fusing, resistant to aging, and UV-, water- and vapor-tight.
• Sealing rivets: Stainless steel, 3.2 mm diameter, 200 per pack.
• Set contents: The set includes a 6 m roll of Nanofil seam insert and 200 stainless steel sealing rivets with a 3.2 mm diameter.

Comparison, what makes this product stand out

Recommended applications

• Making gutter joints in half-round metal gutters in new construction.
• Renovation work on existing gutters, where a mechanical connection without soft soldering is required.
• On-site work in cold or damp conditions, when weather makes soldering impractical.
• Work on pre-coated or heat-sensitive gutters where heat must not be applied.
• Gutter joints in regions prone to snow or wind, where a mechanically secured seam is required.

Frequently asked questions