CORE Twin Wall - The double-walled stainless steel chimney system
Highlights
The simple push-fit connection gives a smooth finish, with limited ridges to make the chimney system aesthetically pleasing.
Core Twin Wall features a distinctive rockwool insulation that maintains its properties even under extreme temperatures, reaching up to 1200°C.
Core Twin Wall's thermal expansion capability of up to 18mm ensures that it retains its structural integrity.
The Core Twin Wall range includes all the required accessory components for standard installations both internally and externally
- Simple push fit design with easy locking mechanism.
- Smooth design, with limited ridges.
- Excellent finish to match most appliances.
- Suitable for low and high kW stove systems.
- Safe from bottom to top, with excellent insulation and low distances to combustible.
- High quality manufacturing process and completely safe.
- Both wood and solid fuel can be used.
G60 and G50 firestop plates to allow 60mm and 50mm distance to combustibles on internal installations.
The Core Twin Wall range includes all the required accessory components for standard installations both internally and externally.
Simple push-fit installation, designed with the installer in mind.
Smooth finish with limited ridges for enhanced aesthetics.
Core Twin Wall installation examples
Non-combustible floor installation example and external example.
Chimney information and guides
Helpful sections for chimney installers
Details & Services
The simple push-fit connection with a smooth design and limited ridges. The finish is in matt black designed to match most appliances.
The structure of the system
For internal routing through wood joist floors, the stove connects to a Core flue. Ventilated firestop plates are installed at each ceiling level to maintain safe clearances from combustible materials.
The system passes through the roof using flashing and terminates with a rain cap to ensure proper draw and protection.
For homes without masonry chimneys, the stove connects to a Core pipe passing through an insulated wall sleeve. Outside, a 135° Tee with cleaning access anchors the vertical flue. Secured by brackets, the chimney rises to the roofline, ending with a rain cap to ensure proper draw and weather protection.
Technical data
| Basic data (dimensions, weight & co.) | |
Diameter (internal) |
100, 130, 150 mm |
Diameter (external) |
150, 180, 200 mm |
Wall thickness per diameter (internal) |
0.4 mm |
Insulation thickness per diameter |
25 mm |
Wall thickness per diameter (outside) |
0.5 mm |
Weight per diameter |
5.8 - 8.4 kg/m |
| Application | |
Flue gas temperature (dry) |
450 °C |
Material (Inner liner) |
AISI 316L-EN 1.4404 |
Material (Insulation) |
Mineral fibre |
Material (Outer case) |
Material No.: 1.4301 |
Thermal resistance by insulation thickness |
0.37 m²K/W |
| General product features | |
Notes |
Thermal expansion: 18 mm / Max. length free standing: 2.0 m above the last support / Max. support spacing (lateral support): 3.0 m |
Technical data
Fuel type
Wood, solid fuel, gas, oil
Diameter (internal)
100, 130, 150
Diameter (external)
150, 180, 200
Liner thickness (internal)
0.4mm
Insulation thickness per diameter
25mm
Weight per diameter (kg/m)
5.8 kg /m - 8.4 kg/m
Outer case thickness
0.5mm
Flue gas temp (dry)
≤ 450°C
Liner material
High grade stainless steel liner 316 liner
Outer case finish
304 stainless steel - painted black (RAL 9005)
Insulation type
High density, rockwool insulation
Thermal expansion
18mm
Max. length free standing
2.0 m above the last support
Max. support spacing (lateral support)
3.0 m
Average thermal resistance (200°C)
0.37m2 k/W
Tools for professionals
Stove shops and chimney installers
Helpful sections for chimney installers
HETAS TRAINING COURSES
A set of training courses at our centre in Washington, Tyne & Wear.
PRODUCT INFORMATION HANGOUTS
We're available to discuss the technical aspects of our product range.
Architects and specifiers
Helpful sections for chimney installers
BIM OBJECTS
3D modelling object available for download.
REMOTE PRODUCT SEMINARS
We're available to discuss the technical aspects of our product range.
Additional tools and resources
Helpful sections for chimney installers
SHOP - PRODUCT INFORMATION
Products available to purchase, as well as full information on our range.
Our range of mobile apps
Apps designed for seeing how our stoves and outdoor appliance look like in your homes and gardens, using the latest technology. We also have our excellent stove and chimney installation app, which has all the technical information and guides for installing our systems.
AUGMENTED REALITY CHIMNEY BUILDER FOR STOVES
This App allows the user to see what a wood burning stove looks like in a room, as well as calculating the components required.
AUGMENTED REALITY OUTDOOR GARDEN FIREPLACE DESIGNER
Simply point and see – it’s as simple as that with our new AR Outdoor Fireplace Designer.
THE SCHIEDEL INSTALLATION ASSISTANT APP
This app was designed for installers to have all the information they require in a few quick clicks.
The Core monthly giveaway
At Schiedel, we value the craftsmanship and dedication of our registered installers. To demonstrate our commitment to your business growth, we are launching an exclusive monthly prize draw from August 2026.
By simply registering your Core TW installations on the Installer Rewards portal, you will automatically gain entry into our monthly draw. Each registration represents an opportunity to win premium Schiedel components, with our inaugural draw taking place in August. Enhance your inventory, reduce your next project costs, and continue delivering excellence with Core TW.
Registering with Schiedel's Installer Rewards means you get points for every install which can be redeemed for Love 2 Shop vouchers!
How to enter
Entering the competition is straightforward. Simply install a system and register it through the Schiedel warranty system. Winners are drawn randomly from the previous month’s registrations and announced on the first working day of every month. Results will be published on Schiedel’s website and social media channels, and winners will also be notified via the retailer where the kit was purchased.
Step 1
Install a Core TW system.
Step 2
Register the install on the Installer Rewards portal. Click here if you have not already registered for the scheme
Step 3
Every registration counts as one automatic entry for that month.
Core giveaway prizes
Our reward scheme operates on a continuous monthly cycle, ensuring regular opportunities for our network of installers. Every Core TW registration counts as an automatic entry for that specific month. With draws taking place on the first working day of every month, a steady rotation of premium components is up for grabs. Install this month, win next month, and select the exact product diameter you need to complete your next full system build.
August
Prima Smooth to Core adaptor
September
Raincap with 25mm mesh
October
Roof support
November
Adjustable starter section 600mm
December
Tapered terminal
January
Tapered terminal
February
Adjustable wall band 90-200mm
March
Anchor plate (screwtype)
April
Anti-splash / anti-downdraught
May
Guy wire bracket
June
Adjustable starter section 1037mm