Product Description

TWPro 125mm Twin Wall Adjustable Base Support Matt Black

Model: 37-125-060

Provide secure vertical support for a TWPro chimney with the TWPro 125mm Twin Wall Adjustable Base Support. Installers can use this load-bearing component inside or outside a building to support the weight of a correctly designed chimney system.

The support offers a small adjustment from 50mm to 80mm from the wall surface. Therefore, the installer can level the chimney and fine-tune its position before securing the complete assembly.

Important: Use only suitable structural fixings for the supporting wall or building surface. The correct fixings will depend on the construction material, condition of the wall and load imposed by the chimney.

Key Features

• Designed for 125mm TWPro twin-wall chimney
• Provides vertical load-bearing support
• Suitable for internal or external installation
• Adjusts from 50mm to 80mm from the wall surface
• Provides 30mm of levelling adjustment
• Helps align the vertical chimney route
• Suitable for use at the base of a correctly designed chimney
• Matt-black powder-coated finish
• Fully welded construction
• Compatible with TWPro and corresponding KW Flue components
• Suitable for correctly designed T600 chimney systems
• Product model: 37-125-060

TWPro 125mm Adjustable Base Support Specification

Read: Why We Think TWPro Twin-Wall Flue Is the Best

• Download the TWPro Information Sheet
• Download the TWPro Installation Sheet
• Brand: TWPro
• Manufacturer: MI Flues
• Product type: adjustable load-bearing base support
• Compatible internal flue diameter: 125mm
• Compatible pipe external diameter: approximately 175mm
• Adjustment range: 50mm to 80mm from the wall surface
• Total adjustment: 30mm
• Installation position: internal or external
• Application: vertical chimney support
• Finish: matt black
• Construction: fully welded
• System joint method: push fit with locking band
• Maximum system operating-temperature class: T600
• Declared chimney clearance from combustible materials: 50mm
• Product model: 37-125-060

What Is Included?

• 1 x TWPro 125mm Adjustable Base Support
• 1 x compatible locking band
• Matt-black finish
• Model: 37-125-060

Please note: Wall fixings are not specified because the correct type depends on the supporting surface. Ask the installer or a suitable fixing manufacturer to select fixings that can safely carry the calculated chimney load.

What Is an Adjustable Base Support Used For?

The adjustable base support carries the vertical weight of the chimney and transfers that load safely to the supporting building surface. Therefore, it performs a different job from a standard wall band, which normally provides lateral support only.

Installers may position the base support below a compatible tee or at another approved load-bearing point within the chimney route. The exact position will depend on the complete TWPro design.

Internal and External Installation

You can use this support in suitable internal or external chimney installations. For example, it may support an external chimney at the base of a vertical rise. Alternatively, an installer may use it at an approved load-bearing point inside a building.

For external installations, make sure the supporting surface remains sound and suitable for the expected load. In addition, use corrosion-resistant fixings that suit both the wall construction and the local environment.

50mm to 80mm Adjustment

The support allows the chimney position to adjust between 50mm and 80mm from the wall surface. This provides 30mm of movement for levelling and final alignment.

As a result, the installer can line up the vertical chimney with the tee, wall penetration or other components. However, this product only offers a small adjustment range.

If the installation requires a greater distance from the wall, choose a compatible longer adjustable base support or another approved TWPro support arrangement.

Application

This component supports a correctly designed 125mm TWPro chimney serving a compatible heating appliance. Depending on the complete system specification, suitable appliances may include:

• 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 particular, confirm the required flue diameter, chimney classification, support positions and permitted chimney height.

Vertical Support Versus Lateral Support

This base support provides vertical load-bearing support. In other words, it helps carry the weight of the chimney sections above it.

Standard wall bands normally control sideways movement instead. Therefore, the complete installation may require both a load-bearing base support and separate wall supports.

Do not rely on ordinary wall bands to carry the chimney’s vertical weight unless the manufacturer clearly approves that arrangement.

Choosing the Correct Fixings

The wall fixings play an important part in the safety of the installation. Therefore, choose fixings that suit the building material and the total calculated load.

Suitable fixing requirements may vary for:

• Solid brickwork
• Concrete
• Blockwork
• Stone walls
• Timber structures
• Walls with external insulation or cladding

Do not fix the support into weak mortar, damaged masonry or decorative cladding alone. Instead, secure it to a suitable structural surface.

If the wall condition is uncertain, ask a structural specialist or suitable fixing manufacturer for advice before installation.

Planning the Support Position

Plan the base-support position before forming wall openings or fixing other chimney components. First, confirm the centre line of the vertical chimney. Then, check the distance from the wall and the position of any tee or connecting pipe.

The chimney must remain straight, stable and correctly aligned. Therefore, use the 50–80mm adjustment for final positioning rather than to correct a poorly planned chimney route.

TWPro System Construction

• Chimney inner casing: 0.4mm 316L-grade stainless steel
• Chimney outer casing: 0.4mm 304-grade stainless steel
• Outer finish: matt-black powder coating
• Chimney insulation: 25mm high-density mineral wool
• System joint method: push fit with locking band
• Maximum operating-temperature class: T600

These construction details describe the connected TWPro insulated chimney system. The adjustable base support carries and positions the compatible chimney components at an approved load-bearing point.

Approvals and System Classification

• Designed for use with a 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 before installation.

Distance to Combustible Materials

The declared minimum distance from the TWPro insulated chimney system to combustible materials is 50mm under its T600 G50 classification.

The support must not reduce this required air gap. In addition, the appliance or another part of the installation may require a greater distance.

Always follow the largest clearance stated in the appliance and chimney-system instructions.

Installation Guidance

• Confirm that this support suits the proposed chimney layout
• Check that the supporting wall can carry the chimney load
• Inspect the wall before drilling or fitting the support
• Mark the required chimney centre line
• Set the support between 50mm and 80mm from the wall
• Use suitable structural fixings for the building material
• Level the support before fully tightening the fixings
• Fit the TWPro component fully into the support connection
• Install the supplied locking band correctly
• Add separate lateral wall supports where required
• Maintain all required distances from combustible materials
• Follow the appliance and TWPro installation instructions

A suitably competent installer should design and fit the chimney. For solid-fuel installations, use a HETAS-registered installer where appropriate.

How Much Chimney Can It Support?

The permitted chimney height above a base support depends on the complete TWPro installation and the manufacturer’s published load limits. It may also depend on the number of bends, tees, offsets and other support points.

Therefore, do not select the support by pipe diameter alone. Instead, calculate the full chimney load and follow the current TWPro technical information.

Additional load-bearing supports may be necessary on taller or more complex chimney routes.

Compatibility

This support fits the 125mm TWPro and corresponding KW Flue systems only. Twin-wall chimney systems from other manufacturers may use different outer diameters, joint profiles and locking methods.

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

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

Inspection and Maintenance

Inspect the base support and its wall fixings during routine chimney maintenance. Check for movement, loose fixings, corrosion or damage to the supporting surface.

External fixings may experience wind, rain and changing temperatures. Therefore, inspect them regularly and replace any damaged or corroded parts with approved components.

If the chimney moves or the support becomes loose, stop using the appliance and ask a competent installer to inspect the system.

TWPro Warranty

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

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

Why Choose the TWPro Twin-Wall System?

TWPro combines a 316L stainless-steel inner casing with dense mineral-wool insulation and a durable matt-black outer casing. In addition, its push-fit joints and locking bands help installers create a neat and secure chimney route.

The support range includes load-bearing, lateral, ceiling and roof components. Therefore, installers can build a complete supported chimney using matching parts from the same tested system.

Why Buy from SNH Tradecentre?

• Specialist supplier of chimney, flue and stove products
• Wide range of matching 125mm TWPro components
• Practical advice from an experienced team
• Close working relationship with MI Flues
• Fast nationwide UK delivery options
• Secure online ordering
• Support before and after your purchase

SNH Tradecentre works closely with MI Flues to process TWPro orders quickly. As a result, we can often arrange same-day dispatch on eligible in-stock orders placed before the relevant cut-off time.

Stock levels, order size and delivery location may affect dispatch times. Therefore, contact us before ordering if you need the component urgently.

Need help selecting the correct chimney support? Call the SNH Tradecentre team on 01843 842727.

Frequently Asked Questions

What does the adjustable base support do?

It provides load-bearing vertical support for a compatible 125mm TWPro chimney and transfers the chimney weight to a suitable structural surface.

Can I install it indoors or outdoors?

Yes. Installers can use the support internally or externally when the location and fixing surface suit the complete chimney design.

How much adjustment does it provide?

It adjusts from 50mm to 80mm from the wall surface. Therefore, it provides 30mm of movement for levelling and alignment.

Does it provide sideways support?

Its main purpose is to provide vertical load-bearing support. The chimney may also need separate wall bands to control lateral movement.

Are the wall fixings included?

Suitable wall fixings must be selected for the supporting surface and calculated chimney load. Do not use unsuitable general-purpose fixings.

Can I fix it to any wall?

No. The supporting surface must have enough strength to carry the chimney load. Avoid fixing into weak masonry, damaged mortar or decorative cladding alone.

Can it support a 135-degree or 90-degree tee?

It may form part of a base-support arrangement for a compatible TWPro tee. However, the installer must follow the approved layout and current TWPro instructions.

What diameter pipe does it fit?

It fits 125mm internal-diameter TWPro pipe, which has an external diameter of approximately 175mm.

Does it fit other twin-wall chimney brands?

No. It is designed for compatible TWPro and corresponding KW Flue components. Do not mix chimney systems unless the manufacturer confirms compatibility.

How far must the chimney remain from combustible materials?

The declared clearance is 50mm under the T600 G50 classification. Always follow any greater clearance required elsewhere in the installation.