







SLIMFLEX-ISO offers a streamlined, high-performance solution for modern chimney renovation installations. Designed for tight masonry flues, it enhances efficiency and durability while simplifying the installation process.
Featuring an integrated 13mm thick sleeved insulation, this flue liner is specifically designed for installation in tight masonry flues. The insulation helps maintain higher flue gas temperatures, significantly enhancing appliance performance while reducing the risk of corrosion caused by condensation at the dew point. The result is a more durable, efficient, and easy-to-install flue liner system.
It is available in 4 diameters (Ø80, Ø100, Ø130 & Ø150) and is supplied in 25m de-coiling boxes or a selection of cut lengths.
The necessary GRIPFLEX fitting, is a required component that ensures the insulation and sleeve remain together with the liner during the installation through the masonry stack and its offsets and bends. Designed for top entry installation and to reinstate the chimneys full system integrity.
> Slim & Flexible: Easy to install in tight and complex chimney layouts
> Enhanced Efficiency: Insulation improves draught and can reduce fuel use
> Durable Design: Avoids dew point and is corrosion-resistant. W V2 suitable for smokeless coal, wood, oil and gas.
>Soot Fire test : @ T450 G
> Easy to Install: GRIPFLEX fitting ensures quick, secure setup
> Space Saving: The 150Ø I.D. 188Ø O.D. fits inside 203 x 203 square Masonry chimney
> Certified: BS EN 1856-2 compliant, CE marked T450N1WV2L50010G
Complete range of ancillaries available
> Compatible with Starflex liner accessories: Pot hanger terminals, clay pots, rain caps, top plate with clamp, register and closure plates and push-fit, clip-on or screw-fit flex adaptors to connecting flue pipe
> Enamel or stainless connecting flue pipes, fire sealing rope, air-vent, CO alarm, paint, thermometer, moisture meter, mastic, sealant, fire-cement, smoke pellet and more.
All of the products offered by Cheminées Poujoulat have been rigorously tested in every configuration by the CERIC Laboratory to ensure they meet highest standards (Building Regulation Document J - Amendments to Approved Documents).
Slimflex-ISO
SLIMFLEX-ISO is slim, strong, and flexible, featuring 13mm high-performance insulation within a tough, temperature-resistant outer sleeve.
The insulation helps maintain flue gas temperatures, which enhances appliance efficiency by improving draught stability, accelerating cold starts, and increasing overall chimney performance. It also prevents condensation at the dew point, reducing the risk of corrosion.
> Operating Temperature Limitation 450°C to 550°C & Soot Fire 1000°C
> CE marking: 0071-CPR-22012 & UKCA 8521-CPR-38868
> Designation: T450 N1 W V2 L50010 G
Gripflex
The GRIPFLEX end fitting is an essential component that securely connects the insulated fabric sleeve to the stainless-steel inner flue. This connection provides a streamlined profile, making it easier to guide the liner through masonry stacks, including any offsets or bends.
GRIPFLEX is fitted at the bottom end of the liner. Below it, a metal nose cone—TireFlex (sold separately)—should be attached. This tool is used in conjunction with a rope to pull the liner smoothly down the chimney stack.
> Agile: Its profiled shape helps with navigating through offsets
> Quick and Easy Installation: Designed for fast and simple setup.
> Includes a Clamping Jubilee clip for the top end of the liner to secure the insulation.
Note: GRIPFLEX is an essential component for the installation of the SLIMFLEX-ISO liner and must be fitted on every installation.
Lining an Existing Chimney
> Older masonry chimneys often need to be relined, as traditional brickwork alone is not suitable for the safe and efficient evacuation of combustion gases. Over time, existing liners may deteriorate, become oversized, or lose their airtightness—posing risks such as poor draught, increased condensation, and even chimney fires. The recommended solution is to reline the chimney with a flexible stainless steel liner, restoring safety, performance, and compliance with current standards and where possible with an insulated replacement liner.
Why Slimflex-ISO?
> Slimflex-ISO is Poujoulat’s next-generation insulated flexible liner system, purpose-built for relining masonry chimneys.
> For even greater efficiency, a pre-insulated liner such as Poujoulat’s Slimflex-ISO is ideal. Its ultra-thin, high-performance insulation enhances flue gas temperature retention, improves appliance performance, and stabilises chimney draught. The Slimflex-ISO system is installed in a single continuous length in CE-marked 316L stainless steel, offering excellent corrosion resistance for long-term durability. Thanks to its slim profile, it’s perfectly suited for tight chimney spaces—broadening installation possibilities while ensuring reliable, high-quality operation.
> Ultra-thin insulation: With just 13mm of high-performance thermal insulation, Slimflex-ISO delivers maximum heat retention while broadening installation options—even in chimneys with tight internal dimensions.
> Improved draught and cold-start performance: The insulation maintains higher flue gas temperatures, significantly improving draught during operation and cold starts, particularly for EcoDesign-ready appliances which have lower flue gas temperatures.
> Enhanced corrosion resistance: By avoiding flue gas temperature lowering to dew point and the associated condensation plus corrosion issues, Slimflex-ISO helps to eliminate internal corrosion, significantly extending the lifespan of your chimney liner.
> Space-saving design: A 150mm internal diameter Slimflex-ISO liner can fit comfortably within a standard 8" x 8" internal brick chimney.
> Perfect for challenging installations: Its exceptional flexibility and compact form allow installation in tight bends or narrow chimney stacks.
> Unique GRIPFLEX end fitting: Secures the insulation and outer sleeve firmly to the stainless steel inner flue—maintaining structural integrity throughout installation, especially in complex chimney routes.
Should I Insulate My Chimney?
> Yes— Modern Eco Design stoves have lower flue gas temperatures and so, to create sufficient draught, the flue gas temperature needs to be maintained as high as possible and especially for masonry chimneys that are exposed. While internal stacks benefit from ambient insulation from the house, exposed stacks and chimneys - such as those on gable ends or above roof level - lose heat rapidly. Insulating these sections is crucial for maintaining strong draught and preventing flue gas condensation. Slimflex-ISO is specifically engineered to address this, making it ideal for these conditions.
Sweeping & Maintenance
> All chimneys serving solid fuel appliances must be swept regularly to remove soot, tars, and corrosive residues. HETAS recommends at least once annually for occasional use and twice annually for more regular operation. Proper maintenance helps prevent blockages and chimney fires and ensures your liner and appliance remain in optimal condition.