Product Description

TWPro 125mm Twin Wall Ventilated Firestop Support Kit Matt Black

Model: 37-125-077

Support a 125mm TWPro chimney where it passes through a suitable floor or ceiling with the TWPro 125mm Ventilated Firestop Support Kit. The complete kit contains two ventilated firestop plates and a support clamp.

The firestop plates help protect the opening around the chimney while still providing the ventilation required by the TWPro system. Meanwhile, the support clamp carries up to 3 metres of vertical chimney when the complete kit is fitted correctly.

This matt-black kit is suitable for correctly designed T600 all-fuel installations. However, a suitably competent installer must check the building structure, appliance requirements and complete chimney design before installation.

Key Features

• Complete ventilated firestop and support kit
• Designed for 125mm TWPro twin-wall chimney
• Includes two ventilated firestop plates
• Includes one load-bearing support clamp
• Supports up to 3 metres of vertical chimney
• Suitable for T600 all-fuel installations
• Helps maintain ventilation around the chimney penetration
• Matt-black finish
• Suitable for compatible solid-fuel, gas and oil appliances
• Compatible with TWPro and corresponding KW Flue components
• Product model: 37-125-077

TWPro Ventilated Firestop Support Kit Specification

• Download the TWPro Information Sheet
• Download the TWPro Installation Sheet
• Brand: TWPro
• Manufacturer: MI Flues
• Product type: ventilated firestop support kit
• Nominal internal chimney diameter: 125mm
• Approximate chimney external diameter: 175mm
• Finish: matt black
• Maximum vertical support: 3 metres
• Installation type: T600 all-fuel firestop installation
• Minimum system distance to combustible materials: 50mm
• Maximum system temperature class: T600
• Product model: 37-125-077

What Is Included?

• 2 x TWPro 125mm ventilated firestop plates
• 1 x TWPro 125mm support clamp
• Finish: matt black
• Model: 37-125-077

What Does the Firestop Support Kit Do?

The kit performs two important jobs. First, the ventilated plates cover the opening around the chimney where it passes through a suitable floor or ceiling. At the same time, their openings allow air to move around the chimney as required by the system design.

Second, the support clamp helps carry the weight of the chimney above the installation point. When correctly fitted, the complete assembly can support up to 3 metres of vertical TWPro chimney.

The kit must form part of a complete fire-stopping detail that suits the surrounding floor or ceiling construction. Therefore, always follow the TWPro installation instructions and relevant Building Regulations.

Application

Use this kit where a 125mm TWPro insulated chimney passes vertically through a suitable internal floor or ceiling and needs both fire stopping and vertical support.

It can form part of a correctly designed chimney serving compatible appliances such as:

• Wood-burning stoves
• Multifuel stoves
• Other suitable solid-fuel appliances
• Compatible gas appliances
• Compatible oil-fired appliances

Always check the appliance manufacturer’s instructions. In addition, confirm the required chimney diameter, temperature class, support positions and fire-stopping method before starting the installation.

Three-Metre Vertical Support

The support clamp can carry up to 3 metres of vertical TWPro chimney above the support point when the full kit is installed correctly.

However, this limit does not replace the need for any additional supports required by the complete chimney design. Bends, offsets, exposed sections and other structural loads may require extra support components.

Therefore, calculate the chimney height and support positions before fitting. Never allow the support kit to carry more chimney than the manufacturer permits.

Why Is the Firestop Ventilated?

The openings in the firestop plates allow ventilation around the outside of the insulated chimney. This airflow forms an important part of the approved TWPro installation arrangement.

For this reason, do not cover, seal or block the ventilation openings with insulation, plaster, sealant or decorative materials. Doing so may prevent the component from working as designed.

TWPro System Construction

• Inner casing: 0.4mm 316L-grade stainless steel
• Outer casing: 0.4mm 304-grade stainless steel
• Outer finish: matt-black powder coating
• Insulation: 25mm injected mineral wool
• Insulation density: 190kg/m³
• Joint system: push fit with locking band
• Maximum operating-temperature class: T600

These construction details describe the TWPro insulated chimney used with the support kit. Its twin-wall construction helps maintain the flue temperature while reducing heat transfer to the outer casing.

Approvals and System Classification

• HETAS-approved chimney system
• EN 1856-1 T600 N1 W V2 L50040 G50
• EN 1856-1 T200 P1 W V2 L50040 O20
• Suitable for compatible negative-pressure applications up to T600
• Suitable for compatible positive-pressure applications up to T200

The required classification depends on the appliance, fuel and complete chimney design. Therefore, check every component in the proposed installation before fitting.

Distance to Combustible Materials

The TWPro system requires a minimum distance of 50mm from the outside of the chimney to combustible materials under its T600 G50 classification.

Keep this space clear around the chimney and firestop opening. Do not fill the clearance with insulation, timber, plasterboard or another combustible material.

The appliance or surrounding construction may require a greater distance. Therefore, always follow the largest clearance stated in the appliance, chimney and building instructions.

Installation Guidance

• Confirm that the kit suits the floor or ceiling construction
• Check that the installation requires a ventilated T600 firestop
• Maintain a minimum 50mm clearance from combustible materials
• Keep every ventilation opening clear and unobstructed
• Fit one firestop plate on each side of the penetration as instructed
• Secure the support clamp to a suitable load-bearing structure
• Use appropriate fixings for the supporting construction
• Do not support more than 3 metres of vertical chimney from this kit
• Add further supports where the chimney design requires them
• Keep the chimney vertical through the support assembly
• Fit all TWPro joints and locking bands correctly
• Follow the appliance and TWPro installation instructions
• Comply with Building Regulations and relevant standards

This kit carries part of the chimney’s weight and forms part of its fire-stopping arrangement. Therefore, a suitably competent installer should design and complete the installation. For solid-fuel systems, use a HETAS-registered installer where appropriate.

Compatibility

This kit fits the 125mm TWPro and corresponding KW Flue chimney systems only. Twin-wall systems from different manufacturers use their own dimensions, support methods and tested installation details.

Therefore, do not use this kit with another chimney brand unless the manufacturer confirms compatibility in writing.

The stated 125mm measurement refers to the internal chimney diameter. Because TWPro uses 25mm of insulation around the inner casing, the connected chimney has an external diameter of approximately 175mm.

Inspection and Maintenance

Check the support kit during routine chimney inspections. Make sure the plates, clamp and fixings remain secure. Also check that the ventilation openings remain clear.

Building movement, decorating work or added insulation can affect the required clearance. Therefore, inspect the area whenever work takes place near the chimney penetration.

TWPro Warranty

• 25-year system warranty, subject to the manufacturer’s terms and conditions
• 2-year warranty on the painted finish

Correct product selection, installation, fuel use and maintenance may affect warranty cover. Therefore, keep your proof of purchase and follow all manufacturer instructions.

Why Choose the TWPro Twin-Wall System?

TWPro combines a 316L stainless-steel inner casing with dense mineral-wool insulation and a durable outer casing. As a result, it provides a strong insulated chimney system for a wide range of compatible heating appliances.

Its push-fit connections and locking bands also help installers form neat and secure joints. In the UK, the same system may carry the KW Flue name. However, always check the product codes and joint design before combining components.

Why Buy from SNH Tradecentre?

SNH Tradecentre works closely with MI Flues, the supplier behind the TWPro chimney system. Therefore, our team can check technical details, confirm availability and help you select compatible supports, firestops and chimney components.

We also work closely with MI Flues to process orders quickly. As a result, we can often arrange same-day dispatch for eligible in-stock orders placed before the daily cut-off time. Stock and delivery times can vary, so please contact us if your order is urgent.

• Close working relationship with MI Flues
• Fast dispatch on eligible in-stock orders
• Nationwide UK delivery options
• Experienced stove and chimney product advice
• Extensive range of matching TWPro components
• Help checking product and system compatibility
• Secure online ordering
• Support before and after your purchase

If you need help planning the supports or firestops for your chimney, contact SNH Tradecentre before ordering.